Tsubota Toshio
| Faculty of Veterinary Medicine Veterinary Medicine Environmental Veterinary Sciences | Professor |
| Hokkaido University Museum | Professor |
Last Updated :2025/11/06
■Researcher basic information
Mail Address
- tsubota
vetmed.hokudai.ac.jp
Researchmap personal page
Home Page URL
J-Global ID
Research Keyword
Research Field
Educational Organization
- Bachelor's degree program, School of Veterinary Medicine
- Doctoral (PhD) degree program, Graduate School of Veterinary Medicine
■Career
Career
Educational Background
Committee Memberships
- 2019 - Present
Japanese Society of Zoo and Wildlife Medicine, Advisor - 1997 - Present
日本獣医学会, 評議員, Society - 1995 - Present
ヒトと動物の関係学会, 評議員, Society - 2017 - 2020
Japanese Society of Veterinary Science Wildlife Biology Section, Chair of Section - Sep. 2017 - Sep. 2019
Japanese Society of Veterinary Science, Board member - 2013 - 2018
Japanese Society of Zoo and Wildlife Medicine, President - 2007 - 2012
Japanese Society of Zoo and Wildlife Medicine, Secretary General - 2001 - 2006
Japanese Society of Zoo and Wildlife Medicine, Vice President - 1997 - 2000
日本繁殖生物学会, 編集委員, Society - 1995 - 2000
日本野生動物医学会, 事務局長, Society - Hokkaido Brown Bear Association, President
- Japan Bear Network, President
- Japan Mammalogical Society, Council
- 日本哺乳類学会, 編集委員, Society
Position History
■Research activity information
Awards
Papers
- Molecular and Functional Characterization of Sika Deer ACE2 as a Receptor for SARS-CoV-2.
Anastasiia Kovba, Manabu Igarashi, Keita Mizuma, Yuma Ohari, Manabu Onuma, Michito Shimozuru, Kotaro Shimizu, Masami Yamanaka, Keita Matsuno, Toshio Tsubota
Microbiology and immunology, 30 Sep. 2025, [International Magazine]
English, Scientific journal, Surveillance of SARS-CoV-2 in white-tailed deer (WTD, Odocoileus virginianus) has revealed its widespread and sustained transmission across North America, with evidence suggesting possible transmission from deer to humans. In the following surveillance studies in other deer species, however, little evidence of infection spread was found, including in sika deer (Cervus nippon) in our previous study. Differences in the structure of the virus entry receptor angiotensin-converting enzyme 2 (ACE2) are known to act as one of the functional barriers to SARS-CoV-2 infection. To investigate the molecular basis of the lack of SARS-CoV-2 transmission to sika deer, we performed structural and functional analyses of the sika deer ACE2 in comparison with WTD ACE2. Comparison of sika deer ACE2 sequence and those of cervid species with WTD ACE2, followed by in silico molecular dynamics analysis, revealed a substitution of lysine to asparagine in position 31 commonly found in cervid ACE2s can potentially alter binding to the SARS-CoV-2 spike (S) protein receptor-binding domain (RBD). Functional assays in cells expressing sika deer and WTD ACE2s showed minimal differences in viral binding and replication, demonstrating that SARS-CoV-2 can similarly utilize ACE2 from both species. These findings suggest that sika deer and possibly other cervids may be highly susceptible to SARS-CoV-2 and highlight the need to investigate other factors impacting virus spread in deer populations. - Understanding Suitable Habitats and Anthropogenic Mortality Risks for King Cobras in Nepal.
Rishi Baral, Binaya Adhikari, Abhisek Sapkota, Saroj Panthi, Chiranjeevi Khanal, Sandesh Gurung, Keshab Raj Sapkota, Naresh Subedi, Bishwanath Rijal, Raju Acharya, Michito Shimozuru, Toshio Tsubota
Ecology and evolution, 15, 9, e72030, Sep. 2025, [International Magazine]
English, Scientific journal, The king cobra (Ophiophagus hannah), the world's largest venomous snake, is a vulnerable species with an expanding distribution in Nepal. This study modeled its current climatically suitable habitat and predicted future changes (2050 and 2070) under the SSP2-4.5 climate change scenario. Using 553 occurrence records and a combination of climate and topographic variables, we developed an ensemble habitat suitability model in BIOMOD2, identifying 23,702.62 km2 of suitable habitat. Under the SSP2-4.5 scenario, the king cobra's climatically suitable habitat is projected to decline by 22% by 2050, with a relatively lower decline of 9% by 2070, indicating a potential partial shift or recovery over time. Within Nepal's protected areas, the currently suitable habitat of 3088.34 km2 is expected to decrease by 14% by 2050 and 13% by 2070, highlighting vulnerabilities even within formally conserved regions. The analysis highlighted Bagmati Province (7311.19 km2) and Gandaki Province (5935.10 km2) as key regions, with significant habitats in Chitwan National Park and Annapurna Conservation Area. However, most suitable habitats (over 60%) are located outside protected areas, emphasizing the need for effective conservation strategies. The distribution of king cobra habitats was found significantly influenced by precipitation during the warmest quarter. Analysis of 94 king cobra mortality records (2000-2024) across Nepal identified eastern lowland and mid-hill regions as critical hotspots, highlighting the urgency for focused conservation initiatives in these high-risk zones. These insights underline the need for urgent conservation measures to protect this species and its rapidly changing habitat under future climate scenarios. - Evaluating the vector potential of deer keds Lipoptena fortisetosa for selected pathogens in Hokkaido sika deer (Cervus nippon yesoensis).
Kotaro Shimizu, Michito Shimozuru, Masami Yamanaka, Genta Ito, Ryo Nakao, Toshio Tsubota
Parasitology international, 107, 103053, 103053, Aug. 2025, [International Magazine]
English, Scientific journal, Deer keds (Lipoptena fortisetosa) are hematophagous insects that parasitize various ungulates, including Hokkaido sika deer (Cervus nippon yesoensis). Although deer keds are potential vectors for several pathogens, their role in disease transmission in Japan remains unclear. This study aimed to evaluate the potential of L. fortisetosa as a vector for selected pathogens in sika deer. Blood samples were collected from 32 sika deer and 149 deer keds (64 from deer and 85 from the environment) from the Rusha area of the Shiretoko Peninsula, Hokkaido, Japan. Nested PCRs and sequencing were performed to detect 18S rRNA gene of Theileria sp. Thrivae, 16S rRNA gene of Anaplasma sp. AP-sd (AP-sd), and flagellin B gene of Borrelia sp. in deer and deer keds. In sika deer, the infection rate was 84 % for Theileria sp. Thrivae, 75 % of AP-sd, and 3 % of Borrelia sp. The prevalence in deer keds collected from deer was 62 % for Theileria sp. Thrivae, 2 % AP-sd, and 1 % Borrelia sp. No pathogens were detected in nonparasitic deer keds captured from the environment. Notably, Theileria sp. Thrivae and AP-sd were detected in deer keds collected from PCR-negative sika deer, suggesting that deer keds acquired pathogens from a previously infested host. The absence of pathogens in non-parasitized deer keds suggests that they do not play as a biological vector for the tested pathogens. This study suggests a potential role for L. fortisetosa as a mechanical vector, emphasizing the need for additional experiments, including infection studies. - Epigenetic Clock in Bears: A Simple Cost-Effective Blood DNA Methylation-Based Age Estimation Method Applicable to Multiple Bear Species.
Michito Shimozuru, Shiori Nakamura, Jumpei Yamazaki, Yojiro Yanagawa, Hiroo Tamatani, Misako Kuroe, Koji Yamazaki, Shinsuke Koike, Yusuke Goto, Tomoko Naganuma, Kahoko Tochigi, Akino Inagaki, Naoki Takekoshi, Seungyun Baek, Nobutaka Sato, Yusuke Honda, Toshio Tsubota, Hideyuki Ito
Ecology and evolution, 15, 5, e71424, May 2025, [International Magazine]
English, Scientific journal, Age is an essential factor to understand the life history and demographic parameters of wildlife. Previously, we established an age estimation method for brown bears based on blood DNA methylation level. In this study, we first applied the brown bear-specific age estimation model to other bear species, including Asian black, polar, sun, and Andean bears. Using blood DNA, we performed bisulfite pyrosequencing to determine the methylation levels at four cytosine-phosphate-guanine (CpG) sites adjacent to a single gene, SLC12A5. The best model specific to brown bears estimated their ages with satisfactory accuracy, with mean absolute error (MAE) of 1.5, 2.1, 2.2, and 0.4 years for Asian black (52 samples from 16 captive and 36 wild bears), polar (27 samples from 21 captive bears), sun bears (11 samples from 8 captive bears), and Andean bears (one captive bear), respectively. Then, we established an Asian black bear-specific age estimation model and a common age estimation model applicable for other bear species (i.e., a pan-bear model) using the methylation levels of the four CpG sites. The best model specific to Asian black bears had high accuracy with MAE of 1.1 after leave-one-out cross-validation (LOOCV). In addition, the best pan-bear model achieved accuracy with MAE of 1.3, 1.2, 2.1, and 2.2 years after LOOCV for brown, Asian black, polar, and sun bears, respectively. The results suggested that the pan-bear age estimation model using the aging marker (CpG sites adjacent to SLC12A5) is a simple, highly accurate, and cost-effective tool that is applicable to Ursidae. - Patterns of intestinal parasite prevalence in brown bears (Ursus arctos) revealed by a 3-year survey on the Shiretoko Peninsula, Hokkaido, Japan
Mizuki Moriyoshi, Naoki Hayashi, Nariaki Nonaka, Ryo Nakao, Masami Yamanaka, Toshio Tsubota, Michito Shimozuru
International Journal for Parasitology: Parasites and Wildlife, 101048, 101048, Elsevier BV, Feb. 2025
Scientific journal - Epidemiological Survey of Canine Distemper Virus Infection: Exploring the Link Between Virus Spread and Invasive Raccoon (Procyon lotor) Population Growth in Hokkaido, Japan
Miku Minamikawa, Mebuki Ito, Anastasiia Kovba, Yumi Kobayashi, Go Abe, Takanori Kooriyama, Ken Maeda, Michito Shimozuru, Toshio Tsubota, Mariko Sashika
Integrative Zoology, Wiley, Dec. 2024
Scientific journal, ABSTRACT
Invasive raccoons (Procyon lotor) naturalized in Hokkaido, Japan, potentially spreading infectious diseases. Canine distemper virus infection is a serious epizootic disease, for which the raccoon is one of the hosts. We investigated the virus's prevalence in Hokkaido's wild raccoons, using 611 serum samples collected from captured raccoons in 2007–2012, 2021, and 2022. Higher seropositivity rates were confirmed in 2007 (32.7%), 2021 (46.4%), and 2022 (46.8%) than in 2008–2012 (0.00%–6.06%), suggesting the occurrence of an epidemic in 2007, 2021, and 2022 and its disappearance in 2008–2012. However, the infection status has recently changed, with high seropositivity rates consecutively confirmed in 2021 and 2022. Logistic regression analysis was performed to investigate the relationships among the catch per unit effort (an index of animal population density), host and environmental factors, and antibody status. The catch per unit effort correlated with seropositivity in 2007. As for environmental factors, the forest area ratio had a weak influence on seroprevalence in 2007; however, the residential area ratio had a clear influence on seroprevalence in 2021 and 2022. The epidemic occurred in forested areas in 2007; nonetheless, recent raccoon population growth and habitat expansion may have caused widespread infections even around residential areas in 2021 and 2022. Continuous monitoring of the infection and reinforcement of raccoon control programs are necessary to avoid serious damage through disease transmission to sympatric native raccoon dog (Nyctereutes procyonoides) and fox (Vulpes vulpes) populations, as well as health consequences for domestic dogs (Canis familiaris). - Regulation of mitochondrial metabolism by hibernating bear serum: Insights into seasonal metabolic adaptations
Mohamed Elfeky, Ayumi Tsubota, Michito Shimozuru, Toshio Tsubota, Kazuhiro Kimura, Yuko Okamatsu-Ogura
Biochemical and Biophysical Research Communications, 736, 150510, 150510, Elsevier BV, Dec. 2024
Scientific journal - Correction to: Predicting the potential habitat of bears under a changing climate in Nepal.
Rishi Baral, Binaya Adhikari, Rajan Prasad Paudel, Rabin Kadariya, Naresh Subedi, Bed Kumar Dhakal, Michito Shimozuru, Toshio Tsubota
Environmental monitoring and assessment, 196, 12, 1233, 1233, 21 Nov. 2024, [International Magazine]
English - Seasonal infestation patterns of ticks on Hokkaido sika deer (Cervus nippon yesoensis).
Kotaro Shimizu, Michito Shimozuru, Masami Yamanaka, Genta Ito, Ryo Nakao, Toshio Tsubota
Parasitology, 1, 9, 15 Nov. 2024, [International Magazine]
English, Scientific journal, Ticks prefer specific feeding sites on a host that are influenced by host–tick and tick–tick interactions. This study focused on the spatiotemporal distribution of ticks in Hokkaido sika deer, an important tick host in Hokkaido, Japan. Tick sampling was performed on the sika deer in the Shiretoko National Park between June and October 2022. Ticks were collected from 9 different body parts of the deer to compare their attachment site preferences. Interspecific and intraspecific relationships among ticks were examined using co-occurrence analysis. The collected ticks were nymphal and adult stages of 4 species: Ixodes ovatus, Ixodes persulcatus, Haemaphysalis japonica and Haemaphysalis megaspinosa. Seasonal variations in tick burden were observed, with I. persulcatus and I. ovatus peaking in June and declining towards October; H. japonica showing low numbers in July and August and increasing from September; and H. megaspinosa appearing from September onwards with little variation. Attachment site preferences varied among species, with a significant preference for the pinna in I. ovatus and I. persulcatus. Haemaphysalis japonica was mainly found on the body and legs between June and August, and shifted to the pinna from September. Haemaphysalis megaspinosa showed a general preference for areas other than the legs. Co-occurrence analysis revealed positive, negative and random co-occurrence patterns among the tick species. Ticks of the same genus and species exhibited positive co-occurrence patterns; I. ovatus showed negative co-occurrence patterns with Haemaphysalis spp. This study revealed the unique attachment site preferences and distinct seasonal distributions of tick species in the Hokkaido sika deer. - Environmental and host factors underlying tick-borne virus infection in wild animals: Investigation of the emerging Yezo virus in Hokkaido, Japan
Mebuki Ito, Miku Minamikawa, Anastasiia Kovba, Hideka Numata, Tetsuji Itoh, Takuma Ariizumi, Asako Shigeno, Yuki Katada, Shiho Niwa, Yurie Taya, Yuto Shiraki, Gita Sadaula Pandey, Nariaki Nonaka, Ryo Nakao, Ryosuke Omori, Yuma Ohari, Norikazu Isoda, Michito Shimozuru, Toshio Tsubota, Keita Matsuno, Mariko Sashika
Ticks and Tick-borne Diseases, 15, 6, 102419, 102419, Elsevier BV, Nov. 2024
Scientific journal - Environmental and host factors underlying tick infestation in invasive raccoons (Procyon lotor) in Hokkaido, Japan
Mebuki Ito, Miku Minamikawa, Anastasiia Kovba, Hideka Numata, Tetsuji Itoh, Yuki Katada, Shiho Niwa, Yurie Taya, Yuto Shiraki, Gita Sadaula Pandey, Samuel Kelava, Nariaki Nonaka, Ryo Nakao, Ryosuke Omori, Yuma Ohari, Norikazu Isoda, Michito Shimozuru, Toshio Tsubota, Keita Matsuno, Mariko Sashika
Ticks and Tick-borne Diseases, 15, 6, 102389, 102389, Elsevier BV, Nov. 2024
Scientific journal - Predicting the potential habitat of bears under a changing climate in Nepal.
Rishi Baral, Binaya Adhikari, Rajan Prasad Paudel, Rabin Kadariya, Naresh Subedi, Bed Kumar Dhakal, Michito Shimozuru, Toshio Tsubota
Environmental monitoring and assessment, 196, 11, 1097, 1097, 23 Oct. 2024, [International Magazine]
English, Scientific journal, In Nepal, the distributions of three bear species vary: sloth bears (Melursus ursinus) in the lowlands, Asiatic black bears (Ursus thibetanus) in the mid-hills, and brown bears (Ursus arctos) in the high Himalayas. We utilized 179 occurrence points for sloth bears, 199 for Asiatic black bears, and 41 points for brown bears to construct a habitat model incorporating climate and topographic variables. Employing various species distribution modeling algorithms in BIOMOD2, the model predicts suitable habitats spanning 10,971.75 km2 for sloth bears; 29,470.75 km2 for Asiatic black bears; and 6152.97 km2 for brown bears. Within protected areas, the habitat for sloth bears is 4120.56 km2, that for Asiatic black bears is 9688.67 km2, and that for brown bears is 4538.67 km2. Chitwan National Park emerged as the prime sloth bear habitat with a core area of 918.55 km2 and a buffer zone of 726.485 km2. The Annapurna Conservation Area was deemed suitable for Asiatic black bears and brown bears, covering 2802.23 km2 and 2795.91 km2, respectively. The models projected a significant reduction in the habitat of these bear species both inside and outside protected areas. As predicted under the Shared Socioeconomic Pathways (SSP)2-4.5 scenario, sloth bears may experience 54.9% (2050) and 44.7% (2070) losses, respectively, of habitat; Asiatic black bears, 11.2% (2050) and 16.8% (2070); and brown bears, 68.41% (2050) and 82.20% (2070) losses. The overlap between sloth bears and black bears spans 38.7 km2, and that between brown bears and black bears is 26.6 km2. Notably, all three bear species exhibited suitability correlations with the intermediate temperature of the driest quarter. Examining current and projected habitats provides essential information for guiding conservation strategies and ensuring the conservation of these bear species in the face of climate change. - Detection and characterization of vector-borne parasites and Wolbachia endosymbionts in greater one-horned rhinoceros (Rhinoceros unicornis) in Nepal.
Gita Pandey Sadaula, Prajwol Manandhar, Bijaya Kumar Shrestha, Amir Sadaula, Naoki Hayashi, Abdelbaset Eweda Abdelbaset, Pradeepa Silwal, Toshio Tsubota, Mackenzie L Kwak, Nariaki Nonaka, Ryo Nakao
Acta tropica, 107344, 107344, 01 Aug. 2024, [International Magazine]
English, Scientific journal, Vector-borne parasite infections affect both domestic and wild animals. They are often asymptomatic but can result in fatal outcomes under natural and human-induced stressors. Given the limited availability of molecular data on vector-borne parasites in Rhinoceros unicornis (greater one-horned rhinoceros), this study employed molecular tools to detect and characterize the vector-borne parasites in rescued rhinoceros in Chitwan National Park, Nepal. Whole blood samples were collected from thirty-six R. unicornis during rescue and treatment operations. Piroplasmida infections were first screened using nested polymerase chain reaction (PCR) targeting 18S ribosomal RNA gene. Wolbachia was detected by amplifying 16S rRNA gene, while filarial nematodes were detected through amplification of 28S rRNA, COI, myoHC and hsp70 genes. Our results confirmed the presence of Theileria bicornis with a prevalence of 75% (27/36) having two previously unreported haplotypes (H8 and H9). Wolbachia endosymbionts were detected in 25% (9/36) of tested samples and belonged to either supergroup C or F. Filarial nematodes of the genera Mansonella and Onchocerca were also detected. There were no significant association between T. bicornis infections and the age, sex, or location from which the animals were rescued. The high prevalence of Theileria with novel haplotypes along with filarial parasites has important ecological and conservational implications and highlights the need to implement parasite surveillance programs for wildlife in Nepal. Further studies monitoring vector-borne pathogens and interspecies transmission among wild animals, livestock and human are required. - Epidemiology and molecular characterization of Mycobacterium tuberculosis including a drug-resistant strain associated with mortality of Asian elephants in Nepal 2019-2022.
Arjun Pandit, Jeewan Thapa, Amir Sadaula, Yasuhiko Suzuki, Chie Nakajima, Susan K Mikota, Naresh Subedi, Bijaya Kumar Shrestha, Michito Shimozuru, Bhawana Shrestha, Bijendra Raya, Sanjay Chaudhary, Sarad Paudel, Toshio Tsubota
Tuberculosis (Edinburgh, Scotland), 148, 102550, 102550, 26 Jul. 2024, [International Magazine]
English, Scientific journal, Tuberculosis (TB) is an emerging threat to the survival of elephants in Nepal. We investigated the lung tissue samples from nine elephants that died from 2019 to 2022 in Nepal using culture, conventional PCR, and loop-mediated isothermal amplification (LAMP) and then performed genotyping of five PCR-positive isolates to understand the possible transmission dynamics of Mycobacterium tuberculosis (Mtb). Results showed that two-thirds (6/9) of elephants were confirmed to be infected from Mtb by LAMP, 5/9 by PCR, and 4/9 by culture. Genotyping of Mtb isolates showed that elephants were infected with the Indo-Oceanic and Beijing lineages including an isoniazid-resistant Beijing lineage. MIRU-VNTR-based phylogeny, gyrA, and katG sequencing showed the possibility of ongoing transmission of Indo-Oceanic lineages and likely transmission of the drug-resistant Beijing lineage from human to elephant. Implementation of comprehensive surveillance and preventive measures are urgently needed to address this zoonotic disease and protect elephants from TB in Nepal. - No Evidence of SARS‐CoV‐2 Infection in Urban Wildlife of Hokkaido, Japan
Anastasiia Kovba, Naganori Nao, Michito Shimozuru, Mariko Sashika, Chihiro Takahata, Kei Sato, Keiya Uriu, Masami Yamanaka, Masanao Nakanishi, Genta Ito, Mebuki Ito, Miku Minamikawa, Kotaro Shimizu, Koichi Goka, Manabu Onuma, Keita Matsuno, Toshio Tsubota
Transboundary and Emerging Diseases, 2024, 1, Wiley, Jan. 2024
Scientific journal, Various domestic and wildlife species have been found susceptible to and infected with SARS‐CoV‐2, the causative agent of COVID‐19, around the globe, raising concerns about virus adaptation and transmission to new animal hosts. The virus circulation in the white‐tailed deer population in North America has further called to action for virus surveillance in the wildlife. Here, we report on the first SARS‐CoV‐2 survey of wild animals in Japan, where frequent wildlife invasions of urban areas have occurred due to the limited predation, field abandonment, the increase of human acclimatization. Genetic testing using nasal swabs and serological screening have been conducted for sika deer, brown bears, raccoons, and raccoon dogs captured in Hokkaido prefecture from the end of the Delta variant wave to the spread of the Omicron variant, between March 2022 and February 2023. No viral RNA was detected in raccoons (0/184), sika deer (0/107), and brown bears (0/14) indicating that the virus was unlikely to spread within the population of these animal species. Among 171 raccoons, 20 raccoon dogs, 100 sika deer, and 13 brown bears, one raccoon, one brown bear, and two deer tested positive in the antibodies screening with multispecies SARS‐CoV‐2 N‐protein ELISA. Still, ELISA‐positive samples tested negative in three other serological tests, emphasizing the importance of confirming serological screening results. Our results suggested that SARS‐CoV‐2 was unlikely to spillback from humans to wildlife in Hokkaido during the study period, with the emergence of new variants, continuous surveillance is of utmost importance. - Age estimation based on blood DNA methylation levels in brown bears.
Shiori Nakamura, Jumpei Yamazaki, Naoya Matsumoto, Miho Inoue-Murayama, Huiyuan Qi, Masami Yamanaka, Masanao Nakanishi, Yojiro Yanagawa, Mariko Sashika, Toshio Tsubota, Hideyuki Ito, Michito Shimozuru
Molecular ecology resources, 23 Mar. 2023, [International Magazine]
English, Scientific journal, Age is an essential trait for understanding the ecology and management of wildlife. A conventional method of estimating age in wild animals is counting annuli formed in the cementum of teeth. This method has been used in bears despite some disadvantages, such as high invasiveness and the requirement for experienced observers. In this study, we established a novel age estimation method based on DNA methylation levels using blood collected from 49 brown bears of known ages living in both captivity and the wild. We performed bisulfite pyrosequencing and obtained methylation levels at 39 cytosine-phosphate-guanine (CpG) sites adjacent to 12 genes. The methylation levels of CpGs adjacent to four genes showed a significant correlation with age. The best model was based on DNA methylation levels at just four CpG sites adjacent to a single gene, SLC12A5, and it had high accuracy with a mean absolute error of 1.3 years and median absolute error of 1.0 year after leave-one-out cross-validation. This model represents the first epigenetic method of age estimation in brown bears, which provides benefits over tooth-based methods, including high accuracy, less invasiveness, and a simple procedure. Our model has the potential for application to other bear species, which will greatly improve ecological research, conservation, and management. - The dynamics of the microbiome in Ixodidae are shaped by tick ontogeny and pathogens in Sarawak, Malaysian Borneo.
Alice C C Lau, Wessam Mohamed Ahmed Mohamed, Ryo Nakao, Manabu Onuma, Yongjin Qiu, Nobuyoshi Nakajima, Michito Shimozuru, Jayasilan Mohd-Azlan, Mohamed Abdallah Mohamed Moustafa, Toshio Tsubota
Microbial genomics, 9, 2, Feb. 2023, [International Magazine]
English, Scientific journal, Tick-borne diseases have recently been considered a potential emerging public health threat in Malaysia; however, fundamental studies into tick-borne pathogens and microbiome appear limited. In this study, six tick species (Ixodes granulatus, Haemaphysalis hystricis, Haemaphysalis shimoga, Dermacentor compactus, Dermacentor steini and Dermacentor atrosignatus) collected from two primary forests and an oil palm plantation in Sarawak, Malaysian Borneo, were used for microbiome analysis targeting bacterial 16S rDNA using next-generation sequencing (NGS). In addition, bacterial species were further characterized in conventional PCRs to identify potential pathogens. Sequences generated from NGS were first filtered with the Decontam package in R before subsequent microbial diversity analyses. Alpha and beta analyses revealed that the genus Dermacentor had the highest microbial diversity, and H. shimoga significantly differed in microbial composition from other tick species. Alpha and beta diversities were also significantly different between developmental stages of H. shimoga. Furthermore, we observed that some bacterial groups were significantly more abundant in certain tick species and developmental stages of H. shimoga. We tested the relative abundances using pairwise linear discriminant analysis effect size (LEfSe), which also revealed significant microbial composition differences between Borrelia-positive and Borrelia-negative I. granulatus ticks. Finally, pathogenic and potentially pathogenic bacteria circulating in different tick species, such as Rickettsia heilongjiangensis, Ehrlichia sp., Anaplasma sp. and Bartonella spp. were characterized by PCR and sequencing. Moreover, Coxiella and Francisella-like potential symbionts were identified from H. shimoga and D. steini, respectively. More studies are required to unravel the factors associated with the variations observed in this study. - Regulation of protein and oxidative energy metabolism are down-regulated in the skeletal muscles of Asiatic black bears during hibernation
Mitsunori Miyazaki, Michito Shimozuru, Yu Kitaoka, Kenya Takahashi, Toshio Tsubota
Scientific Reports, 12, 1, Springer Science and Business Media LLC, 16 Nov. 2022
Scientific journal, Abstract
Hibernating animals exhibit an unexplained physiological characteristic of skeletal muscles being atrophy resistance, in which case muscle mass and strength remain almost unchanged both before and after hibernation. In this study, we examined the alterations in the regulatory systems of protein and energy metabolism in the skeletal muscles of Asiatic black bears during hibernation. Skeletal muscle samples (vastus lateralis muscle) were collected from identical individuals (n = 8) during the active (July) and hibernating (February) periods, while histochemical and biochemical analyses were performed. We observed no significant alterations in body weight, muscle fiber size, and fiber type composition during the active and hibernating periods, indicating that the skeletal muscles of bears are very well preserved during hibernation. In hibernating bear skeletal muscles, both regulatory pathways of muscle protein synthesis (Akt/mechanistic target of rapamycin and mitogen-activated protein kinase systems) and proteolysis (ubiquitin–proteasome and autophagy systems) were down-regulated. Gene expression levels of factors regulating oxidative metabolism were also decreased in hibernating bear skeletal muscles. This is likely an adaptive strategy to minimize the energy wasting of amino acids and lipids during hibernation, which is accompanied by a prolonged period of disuse and starvation. - Detection of a Babesia sp. genotype closely related to marsupial-associated Babesia spp. in male Haemaphysalis shimoga from Sarawak, Malaysian Borneo.
Alice Cc Lau, Yongjin Qiu, Mohamed Abdallah Mohamed Moustafa, Ryo Nakao, Michito Shimozuru, Manabu Onuma, Nobuyoshi Nakajima, Mariko Sashika, Jayasilan Mohd-Azlan, Toshio Tsubota
The Journal of veterinary medical science, 84, 11, 1469, 1473, 16 Sep. 2022, [Domestic magazines]
English, Scientific journal, In this study, Babesia screening was conducted in 55 rodents and 160 tick samples collected from primary forests and an oil palm plantation in Sarawak, Malaysian Borneo. PCR targeting the 18S ribosomal DNA revealed the presence of Babesia spp. DNA detected in two questing male Haemaphysalis shimoga ticks collected from the oil palm plantation. Sequence analysis revealed that both sequences were identical and had 98.6% identity to a Babesia macropus sequence obtained from Eastern grey kangaroos (Macropus giganteus) in Australia. Phylogenetic tree revealed clustering with marsupial-associated Babesia spp. in the Babesia sensu stricto clade. Whether or not H. shimoga is the competent vector and the importance of the Babesia sp. detected in this study warrants more investigation. - Estimation of breeding population size using DNA‐based pedigree reconstruction in brown bears
Michito Shimozuru, Mina Jimbo, Keisuke Adachi, Kei Kawamura, Yuri Shirane, Yoshihiro Umemura, Tsuyoshi Ishinazaka, Masanao Nakanishi, Mayu Kiyonari, Masami Yamanaka, Yukihiro Amagai, Ayaho Ijuin, Tomoki Sakiyama, Shinsuke Kasai, Takane Nose, Masataka Shirayanagi, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota, Keita Fukasawa, Hiroyuki Uno
Ecology and Evolution, 12, 9, Wiley, Sep. 2022
Scientific journal - Anthelmintic Baiting of Foxes against Echinococcus multilocularis in Small Public Area, Japan.
Kohji Uraguchi, Takao Irie, Hirokazu Kouguchi, Azusa Inamori, Mariko Sashika, Michito Shimozuru, Toshio Tsubota, Kinpei Yagi
Emerging infectious diseases, 28, 8, 1677, 1680, Aug. 2022, [International Magazine]
English, Scientific journal, We distributed anthelmintic baits on a university campus in Japan inhabited by foxes infected with Echinococcus multilocularis to design an effective baiting protocol for small public areas. High-density baiting can reduce the risk for human exposure to the parasite to near zero. However, monthly baiting is recommended to maintain this effect. - Diet selection and asocial learning: Natal habitat influence on lifelong foraging strategies in solitary large mammals
Mina Jimbo, Tsuyoshi Ishinazaka, Yuri Shirane, Yoshihiro Umemura, Masami Yamanaka, Hiroyuki Uno, Mariko Sashika, Toshio Tsubota, Michito Shimozuru
Ecosphere, 13, 7, Wiley, Jul. 2022
Scientific journal - Semen collection by urethral catheterization and electro-ejaculation with different voltages, and the effect of holding temperature and cooling rate before cryopreservation on semen quality in the Japanese macaque (Macaca fuscata).
Noboru Takaesu, Chihiro Kanno, Kosuke Sugimoto, Masashi Nagano, Akihisa Kaneko, Yoriko Indo, Hiroo Imai, Hirohisa Hirai, Munehiro Okamoto, Mariko Sashika, Michito Shimozuru, Seiji Katagiri, Toshio Tsubota, Yojiro Yanagawa
The Journal of veterinary medical science, 84, 3, 429, 438, 15 Mar. 2022, [Domestic magazines]
English, Scientific journal, In the Japanese macaque, semen has been collected by electro-ejaculation (EE), using the higher voltage stimuli compared to other species including genus Macaca. Semen coagulates immediately after ejaculation, which makes difficult to produce high-quality semen for artificial insemination. Recently, semen collection using urethral catheterization (UC) has been reported in carnivore and this technique may allow semen collection without coagulation in a less invasive manner. Further, the temporal preservation temperature and cooling rate of semen during cryopreservation affect post thawing sperm quality. In this study, to improve semen quality and quantity, as well as the animal welfare, semen collection was performed by EE with high (5-15 V) or low (3-6 V) voltage, UC and a combination of the two (EE-UC). It has been suggested that a high voltage is necessary for semen collection, but 10 V stimulation was effective enough and 15 V is for additional sperm collection. Also, liquid semen was collected by EE-UC and this could increase the total number of sperm. Further, to improve the post thawing sperm motility, semen was kept at four temperatures (4, 15, 25 and 37°C) for 60 min, and processed with two cooling procedures (slow cooling before second dilution and fast cooling after second dilution). Holding semen at 25°C and fast cooling after the second dilution maintained progressive motile sperm rate. The present results will contribute to the improvement of semen collection and animal welfare of Japanese macaques. - Habitat occupancy of sloth bear Melursus ursinus in Chitwan National Park, Nepal
Rajan Prasad Paudel, Rabin Kadariya, Babu Ram Lamichhane, Naresh Subedi, Mariko Sashika, Michito Shimozuru, Toshio Tsubota
ECOLOGY AND EVOLUTION, 12, 3, Mar. 2022
English, Scientific journal - Ovulatory follicle size investigated by ultrasonography and single artificial insemination with ovulation induction in the Japanese macaque (Macaca fuscata)
Noboru Takaesu, Masako Minami, Masashi Nagano, Akihisa Kaneko, Yoriko Indo, Hiroo Imai, Hirohisa Hirai, Mariko Sashika, Michito Shimozuru, Munehiro Okamoto, Seiji Katagiri, Toshio Tsubota, Yojiro Yanagawa
Japanese Journal of Veterinary Research, 70, 1, 5, 17, Feb. 2022, [Peer-reviewed]
English, Scientific journal - Diel and monthly activity pattern of brown bears and sika deer in the Shiretoko Peninsula, Hokkaido, Japan
Kei KAWAMURA, Mina JIMBO, Keisuke ADACHI, Yuri SHIRANE, Masanao NAKANISHI, Yoshihiro UMEMURA, Tsuyoshi ISHINAZAKA, Hiroyuki UNO, Mariko SASHIKA, Toshio TSUBOTA, Michito SHIMOZURU
Journal of Veterinary Medical Science, 84, 8, 1146, 1156, Japanese Society of Veterinary Science, 2022
Scientific journal - Supplementing cultured human myotubes with hibernating bear serum results in increased protein content by modulating Akt/FOXO3a signaling.
Mitsunori Miyazaki, Michito Shimozuru, Toshio Tsubota
PloS one, 17, 1, e0263085, 2022, [International Magazine]
English, Scientific journal, Hibernating bears remain in their dens for 5-7 months during winter and survive without eating or drinking while staying inactive. However, they maintain their physical functions with minimal skeletal muscle atrophy and metabolic dysfunction. In bears, resistance to skeletal muscle atrophy during hibernation is likely mediated by seasonally altered systemic factors that are independent of neuromuscular activity. To determine whether there are components in bear serum that regulate protein and energy metabolism, differentiated human skeletal muscle cells were treated with bear serum (5% in DMEM/Ham's F-12, 24 h) collected during active summer (July) and hibernating winter (February) periods. The serum samples were collected from the same individual bears (Ursus thibetanus japonicus, n = 7 in each season). Total protein content in cultured skeletal muscle cells was significantly increased following a 24 h treatment with hibernating bear serum. Although the protein synthesis rate was not altered, the expression of MuRF1 protein, a muscle-specific E3 ubiquitin ligase was significantly decreased along with a concomitant activation of Akt/FOXO3a signaling. Increased levels of insulin-like growth factor-1 (IGF-1) were also observed in hibernating bear serum. These observations suggest that protein metabolism in cultured human myotubes may be altered when incubated with hibernating bear serum, with a significant increase in serum IGF-1 and diminished MuRF1 expression, a potential target of Akt/FOXO3a signaling. A protein sparing phenotype in cultured muscle cells by treatment with hibernating bear serum holds potential for the development of methods to prevent human muscle atrophy and related disorders. - Genome Sequences of Two Mycobacterium tuberculosis Isolates from Asian Elephants in Nepal.
Sarad Paudel, Evan P Brenner, Syeda A Hadi, Yasuhiko Suzuki, Chie Nakajima, Toshio Tsubota, Kamal Prasad Gairhe, Bhagwan Maharjan, Srinand Sreevatsan
Microbiology resource announcements, 10, 36, e0061421, 09 Sep. 2021, [International Magazine]
English, Scientific journal, This report describes the genome sequences of two Mycobacterium tuberculosis isolates, S1 and S3, recovered from Asian elephants in Nepal. These genome sequences will enhance our understanding of the genomic epidemiology of Mycobacterium tuberculosis in Asian elephants. - Dining from the coast to the summit: Salmon and pine nuts determine the summer body condition of female brown bears on the Shiretoko Peninsula
Yuri Shirane, Mina Jimbo, Masami Yamanaka, Masanao Nakanishi, Fumihiko Mori, Tsuyoshi Ishinazaka, Mariko Sashika, Toshio Tsubota, Michito Shimozuru
ECOLOGY AND EVOLUTION, 11, 10, 5204, 5219, May 2021
English, Scientific journal - SPECIFIC MOLECULAR DETECTION OF PIROPLASMS AND CHARACTERIZATION OF beta-TUBULIN FOR A NOVEL BABESIA SPECIES IN SIKA DEER (CERVUS NIPPON YESOENSIS)
Mohamed Abdallah Mohamed Moustafa, Jason L. Anders, Wessam Mohamed Ahmed Mohamed, Kyunglee Lee, Elzahara Elbaz, Mariko Sashika, Ryo Nakao, Michito Shimozuru, Toshio Tsubota
JOURNAL OF ZOO AND WILDLIFE MEDICINE, 52, 1, 200, 205, Mar. 2021
English, Scientific journal - Changes in liver microRNA expression and their possible regulatory role in energy metabolism-related genes in hibernating black bears
Kazuhei Nishida, Michito Shimozuru, Yuko Okamatsu-Ogura, Mitsunori Miyazaki, Tsukasa Soma, Mariko Sashika, Toshio Tsubota
JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMS AND ENVIRONMENTAL PHYSIOLOGY, 191, 2, 397, 409, Mar. 2021
English, Scientific journal - Amblyomma testudinarium infestation on a brown bear (Ursus arctos yesoensis) captured in Hokkaido, a northern island of Japan
Ryo Nakao, Kohei Shinjo, Tomoki Sakiyama, Shohei Ogata, Kodai Kusakisako, Gohta Kinoshita, Doaa Naguib, Elisha Chatanga, Wessam Mohamed Ahmed Mohamed, Mohamed Abdallah Mohamed Moustafa, Keita Matsuno, Takuya Ito, Nariaki Nonaka, Mariko Sashika, Toshio Tsubota, Michito Shimozuru
PARASITOLOGY INTERNATIONAL, 80, Feb. 2021
English, Scientific journal - Utilizing attached hard ticks as pointers to the risk of infection byBabesiaandTheileriaspecies in sika deer (Cervus nippon yesoensis), in Japan
Elzahara Elbaz, Mohamed Abdallah Mohamed Moustafa, Kyunglee Lee, Alice Lau Ching Ching, Michito Shimozuru, Mariko Sashika, Ryo Nakao, Sabry Ahmed El-khodery, Toshio Tsubota
EXPERIMENTAL AND APPLIED ACAROLOGY, 82, 3, 411, 429, Nov. 2020
English, Scientific journal - Molecular detection of apicomplexan protozoa in Hokkaido brown bears (Ursus arctos yesoensis) and Japanese black bears (Ursus thibetanus japonicus)
Mohamed Abdallah Mohamed Moustafa, Ayaka Sasaki, Michito Shimozuru, Ryo Nakao, Mariko Sashika, Koji Yamazaki, Shinsuke Koike, Junpei Tanaka, Hiroo Tamatani, Masami Yamanaka, Tsuyoshi Ishinazaka, Toshio Tsubota
PARASITOLOGY RESEARCH, 119, 11, 3739, 3753, Nov. 2020
English, Scientific journal - Predation impacts of invasive raccoons on rare native species
Sakura Oe, Mariko Sashika, Ayako Fujimoto, Michito Shimozuru, Toshio Tsubota
SCIENTIFIC REPORTS, 10, 1, Nov. 2020
English, Scientific journal - Hair growth in brown bears and its application to ecological studies on wild bears
Mina Jimbo, Naoya Matsumoto, Hideyuki Sakamoto, Yojiro Yanagawa, Yoshiko Torii, Masami Yamanaka, Tsuyoshi Ishinazaka, Yuri Shirane, Mariko Sashika, Toshio Tsubota, Michito Shimozuru
MAMMAL STUDY, 45, 4, 337, 345, Oct. 2020
English, Scientific journal - Detection of Borrelia burgdorferi Sensu Lato and Relapsing Fever Borrelia in Feeding Ixodes Ticks and Rodents in Sarawak, Malaysia: New Geographical Records of Borrelia yangtzensis and Borrelia miyamotoi
Alice C. C. Lau, Yongjin Qiu, Mohamed Abdallah Mohamed Moustafa, Ryo Nakao, Michito Shimozuru, Manabu Onuma, Jayasilan Mohd-Azlan, Toshio Tsubota
PATHOGENS, 9, 10, Oct. 2020
English, Scientific journal - Maternal human habituation enhances sons' risk of human-caused mortality in a large carnivore, brown bears
Michito Shimozuru, Yuri Shirane, Masami Yamanaka, Masanao Nakanishi, Tsuyoshi Ishinazaka, Shinsuke Kasai, Takane Nose, Masataka Shirayanagi, Mina Jimbo, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota
SCIENTIFIC REPORTS, 10, 1, Oct. 2020
English, Scientific journal - Development of a noninvasive photograph-based method for the evaluation of body condition in free-ranging brown bears
Yuri Shirane, Fumihiko Mori, Masami Yamanaka, Masanao Nakanishi, Tsuyoshi Ishinazaka, Tsutomu Mano, Mina Jimbo, Mariko Sashika, Toshio Tsubota, Michito Shimozuru
PEERJ, 8, Sep. 2020
English, Scientific journal - Hibernating bear serum hinders osteoclastogenesis in-vitro
Alireza Nasoori, Yuko Okamatsu-Ogura, Michito Shimozuru, Mariko Sashika, Toshio Tsubota
PLOS ONE, 15, 8, Aug. 2020
English, Scientific journal - Morphological and histological studies on the epididymis and deferent duct of the Sunda porcupine (Hystrix javanica)
Anni Nurliani, Motoki Sasaki, Teguh Budipitojo, Toshio Tsubota, Nobuo Kitamura
MAMMAL STUDY, 45, 3, 201, 211, Jul. 2020
English, Scientific journal - Genetic population structure of invasive raccoons (Procyon lotor) in Hokkaido, Japan: Unique phenomenon caused by pet escape or abandonment.
Minami W Okuyama, Michito Shimozuru, Mariko Nakai, Emi Yamaguchi, Kei Fujii, Ken-Ichiro Shimada, Tohru Ikeda, Toshio Tsubota
Scientific reports, 10, 1, 8108, 8108, 15 May 2020, [Peer-reviewed], [International Magazine]
English, Phylogeographic studies can resolve relationships between genetic population structure of organisms and geographical distributions. Raccoons have become feral in Japan, and in Hokkaido island, they have been rapidly increasing in number and spreading since the 1970s. We analyzed mitochondrial (mtDNA) and microsatellite DNA to understand the current phylogenetic distribution and invasive founder events. Overall, Hokkaido raccoons maintained high genetic diversity (i.e., the level of heterozygosity was comparable to the original habitat, North America). Based on mtDNA distribution and microsatellite diversity, Hokkaido raccoons were divided into six management units. However, mtDNA haplotype distributions and genetic structures based on microsatellites did not always correspond to each other (e.g., two geographically and genetically separated populations showed similar mtDNA distributions). In addition, a high degree of genetic admixture was observed in every unit, and the degree of genetic differentiation was low even between regions separated by long distances. Compared with other countries in Europe where genetic distribution of introduced raccoons is more clearly structured, the current results represent a unique and complex phenomenon of pet escape/abandonment in Hokkaido: i.e., genetically related colonies were introduced into multiple regions as founder events, resulting in the current state in which raccoons are not clearly genetically differentiated even 40 years after introduction. - Male reproductive input, breeding tenure, and turnover in high-density brown bear populations on the Shiretoko Peninsula, Hokkaido, Japan.
Michito Shimozuru, Yuri Shirane, Mina Jumbo, Masami Yamanaka, Masanao Nakanishi, Tsuyoshi Isinazaka, Shinsuke Kasai, Takane Nose, Yasushi Fujimoto, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota
Canadian Journal of Zoology, 98, 3, 175, 185, Canadian Science Publishing, 2020, [Peer-reviewed]
Scientific journal, Male reproductive behavior has not been thoroughly investigated in large, non-social mammals. We studied male reproductive input using field observations and microsatellite DNA data for the brown bear (Ursus arctos yesoensis Lydekker, 1897) population in a special wildlife protection area on the Shiretoko Peninsula in Hokkaido, Japan. We identified the father of 82 offspring born between 2006 and 2018 from 54 litters produced by 20 females and revealed that they were sired by a total of 19 males. Overall, paternity was distributed relatively evenly among different males, although litter production tended to be skewed to a few bears in some years. Male breeding tenure varied among individuals, but most tenures were within the range of 1 to 6 years. Human-caused mortality, mostly occurring near human residential areas, induced male turnover, indicating that the special wildlife protection area located in the inner part of the Shiretoko Peninsula is not free from human impact. The frequency of successful reproduction was highest in 10- to 14-year-old bears, which is consistent with the period when males reach physical maturity. These results contribute to an understanding of breeding systems in large solitary mammals and to appropriate conservation and management strategies for brown bear populations. - Epidemiological study of sarcoptic mange in raccoon dogs (Nyctereutes procyonoides albus) in Hokkaido, Japan
Mariko Sashika, Go Abe, Mariko Nakai, Aya Osaki, Ayako Fujimoto, Toshio Tsubota
JAPANESE JOURNAL OF VETERINARY RESEARCH, 67, 4, 253, 261, Nov. 2019
English, Scientific journal - Comparison of feeding habits and habitat use between invasive raccoons and native raccoon dogs in Hokkaido, Japan.
Aya Osaki, Mariko Sashika, Go Abe, Kohei Shinjo, Ayako Fujimoto, Mariko Nakai, Michito Shimozuru, Toshio Tsubota
BMC ecology, 19, 1, 35, 35, 11 Sep. 2019, [Peer-reviewed], [International Magazine]
English, BACKGROUND: In Japan, invasive raccoons cause severe ecological and social problems by transmitting pathogens to humans, livestock, and native species, causing substantial crop damage, and competing with native species. Possible competition between invasive raccoons and native raccoon dogs is of concern in Japan because Japanese raccoon dogs have a limited distribution and are native only to Japan and the two species have similar characteristics. We assessed potential competition between raccoons and raccoon dogs by comparing feeding habits and habitat use. RESULTS: Both species were captured in Hokkaido, Japan from 2004 to 2017. More raccoons were captured close to agricultural land at the forest periphery (70.1%, 358/511); conversely, more raccoon dogs were captured in the forest core (74.9%, 253/338). Feeding habits were then examined by fecal analysis and stable isotope analyses. Fecal analysis revealed both species to be opportunistic omnivores that consumed easily found food items. However, raccoon feces contained more crops, whereas raccoon dog feces contained more insects, reflecting the different locations in which the species were trapped. Moreover, stable isotope ratios were significantly higher in raccoons than raccoon dogs (Corn has the highest carbon stable isotope (δ13C) value, and amphibians and reptiles are high in nitrogen stable isotope (δ15N); forest resources such as insects and wild fruits are low in δ13C and δ15N). CONCLUSIONS: We conclude that both species ate similar food types, but their food preferences appeared to differ. Raccoon and raccoon dog habitat use also differed, possibly because the two species inhabited areas where they could easily obtain their preferred foods. Therefore, the current feeding habits and habitat use of raccoons do not appear to overlap sufficiently with those of raccoon dogs to impact the latter. The results of this study, particularly the stable isotope data, may provide a useful precedent for future studies of competition in medium-sized mammals, particularly canids. - An immunohistochemical study on testicular steroidogenesis in the Sunda porcupine (Hystrix javanica).
Nurliani A, Sasaki M, Budipitojo T, Tsubota T, Suzuki M, Kitamura N
The Journal of veterinary medical science, 81, 9, 1285, 1290, Sep. 2019, [Peer-reviewed]
English, Scientific journal - Human TB threat to wild elephants
Sarad Paudel, Toshio Tsubota, Susan K. Mikota
NATURE, 571, 7764, 174, 174, Jul. 2019
English - Sex-biased dispersal and inbreeding avoidance in Hokkaido brown bears
Shirane, Yuri, Shimozuru, Michito, Yamanaka, Masami, Tsuruga, Hifumi, Nakanishi, Masanao, Ishinazaka, Tsuyoshi, Nose, Takane, Kasai, Shinsuke, Shirayanagi, Masataka, Masuda, Yasushi, Fujimoto, Yasushi, Mano, Tsutomu, Sashika, Mariko, Tsubota, Toshio
JOURNAL OF MAMMALOGY, 100, 4, 1317, 1326, Jul. 2019, [Peer-reviewed]
English, Scientific journal - Incidence of Multiple Paternity and Inbreeding in High-Density Brown Bear Populations on the Shiretoko Peninsula, Hokkaido, Japan.
Shimozuru M, Shirane Y, Tsuruga H, Yamanaka M, Nakanishi M, Ishinazaka T, Kasai S, Nose T, Masuda Y, Fujimoto Y, Mano T, Tsubota T
The Journal of heredity, 110, 3, 321, 331, Oxford University Press (OUP), May 2019, [Peer-reviewed]
Scientific journal - Mixed Mycobacterium tuberculosis Lineage Infection in 2 Elephants, Nepal.
Paudel S, Nakajima C, Mikota SK, Gairhe KP, Maharjan B, Subedi S, Poudel A, Sashika M, Shimozuru M, Suzuki Y, Tsubota T
Emerging infectious diseases, 25, 5, 1031, 1032, May 2019, [Peer-reviewed]
English - Heart rate during hyperphagia differs between two bear species
Boris Fuchs, Koji Yamazaki, Alina L. Evans, Toshio Tsubota, Shinsuke Koike, Tomoko Naganuma, Jon M. Arnemo
BIOLOGY LETTERS, 15, 1, Jan. 2019
English, Scientific journal - Tuberculosis threat in Asian elephants
Sarad Paudel, Susan K. Mikota, Toshio Tsubota
SCIENCE, 363, 6425, 356, 356, Jan. 2019
English - Skeletal muscles of hibernating black bears show minimal atrophy and phenotype shifting despite prolonged physical inactivity and starvation.
Mitsunori Miyazaki, Michito Shimozuru, Toshio Tsubota
PloS one, 14, 4, e0215489, 2019, [Peer-reviewed], [International Magazine]
English, Scientific journal, Hibernating mammals experience prolonged periods of torpor and starvation during winter for up to 5-7 months. Though physical inactivity and malnutrition generally lead to profound loss of muscle mass and metabolic dysfunction in humans, hibernating bears show limited muscle atrophy and can successfully maintain locomotive function. These physiological features in bears allow us to hypothesize that hibernating bears uniquely alter the regulation of protein and energy metabolism in skeletal muscle which then contributes to "muscle atrophy resistance" against continued physical inactivity. In this study, alteration of signaling pathways governing protein and energy metabolisms was examined in skeletal muscle of the Japanese black bear (Ursus thibetanus japonicus). Sartorius muscle samples were collected from bear legs during late November (pre-hibernation) and early April (post-hibernation). Protein degradation pathways, through a ubiquitin-proteasome system (as assessed by increased expression of murf1 mRNA) and an autophagy-dependent system (as assessed by increased expression of atg7, beclin1, and map1lc3 mRNAs), were significantly activated in skeletal muscle following hibernation. In contrast, as indicated by a significant increase in S6K1 phosphorylation, an activation state of mTOR (mammalian/mechanistic target of rapamycin), which functions as a central regulator of protein synthesis, increased in post-hibernation samples. Gene expression of myostatin, a negative regulator of skeletal muscle mass, was significantly decreased post-hibernation. We also confirmed that the phenotype shifted toward slow-oxidative muscle and mitochondrial biogenesis. These observations suggest that protein and energy metabolism may be altered in skeletal muscle of hibernating bears, which then may contribute to limited loss of muscle mass and efficient energy utilization. - Serodiagnosis of elephant tuberculosis: a useful tool for early identification of infected elephants at the captive-wild interface
Sarad Paudel, Susan K. Mikota, Jeewan Thapa, Konstantin P. Lyashchenko, Kamal P. Gairhe, Ishwari Prasad Dhakal, Naresh Subedi, Bhagwan Maharjan, Suraj Subedi, Gretchen E. Kaufman, Toshio Tsubota
EUROPEAN JOURNAL OF WILDLIFE RESEARCH, 64, 6, Dec. 2018
English, Scientific journal - High genetic diversity and distinct ancient lineage of Asiatic black bears revealed by non-invasive surveys in the Annapurna Conservation Area, Nepal.
Kadariya R, Shimozuru M, Maldonado JE, Moustafa MAM, Sashika M, Tsubota T
PloS one, in press, 12, e0207662, Dec. 2018, [Peer-reviewed]
English, Scientific journal - Sex-biased natal dispersal in Hokkaido brown bears revealed through mitochondrial DNA analysis
Shirane Yuri, Shimozuru Michito, Yamanaka Masami, Tsuruga Hifumi, Hirano Saiko, Nagano Natsuo, Moriwaki Jun, Nakanishi Masanao, Ishinazaka Tsuyoshi, Nose Takane, Kasai Shinsuke, Shirayanagi Masataka, Masuda Yasushi, Fujimoto Yasushi, Osada Masahiro, Akaishi Masao, Mano Tsutomu, Masuda Ryuichi, Sashika Mariko, Tsubota Toshio
EUROPEAN JOURNAL OF WILDLIFE RESEARCH, 64, 6, 65, Dec. 2018, [Peer-reviewed]
English, Scientific journal - Differentiation of Japanese Black Bears' Adipose-Derived Stem Cells to Osteoblasts
Alireza Nasoori, Yuko Okamatsu-Ogura, Woongchul Shin, Michito Shimozuru, Mohamed Abdallah Mohamed Moustafa, Toshio Tsubota
JOURNAL OF BONE AND MINERAL RESEARCH, 33, 224, 224, Nov. 2018
English - Evaluation of body condition using body mass and chest girth in brown bears of Hokkaido, Japan (Ursus arctos yesoensis)
Jun Moriwaki, Ryosuke Omori, Michito Shimozuru, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota
Japanese Journal of Veterinary Research, 66, 2, 71, 81, 01 May 2018, [Peer-reviewed]
English, Scientific journal - Serological survey of severe fever with thrombocytopenia syndrome virus infection in Sika deer and rodents in Japan
Tapiwa Lundu, Kentaro Yoshii, Shintaro Kobayashi, Shigeru Morikawa, Toshio Tsubota, Naoaki Misawa, Daisuke Hayasaka, Hiroaki Kariwa
Japanese Journal of Veterinary Research, 66, 1, 21, 28, 2018, [Peer-reviewed]
English, Scientific journal - First molecular detection and characterization of Hepatozoon and Sarcocystis spp. in field mice and voles from Japan
Mohamed Abdallah Mohamed Moustafa, Michito Shimozuru, Wessam Mohamed, Kyle Rueben Taylor, Ryo Nakao, Mariko Sashika, Toshio Tsubota
PARASITOLOGY RESEARCH, 116, 8, 2321, 2325, Aug. 2017, [Peer-reviewed]
English, Scientific journal - Reproductive parameters and cub survival of brown bears in the Rusha area of the Shiretoko Peninsula, Hokkaido, Japan
Michito Shimozuru, Masami Yamanaka, Masanao Nakanishi, Jun Moriwaki, Fumihiko Mori, Masakatsu Tsujino, Yuri Shirane, Tsuyoshi Ishinazaka, Shinsuke Kasai, Takane Nose, Yasushi Masuda, Toshio Tsubota
PLOS ONE, 12, 4, Apr. 2017, [Peer-reviewed]
English, Scientific journal - Molecular identification and characterization of piroplasm species in Hokkaido sika deer (Cervus nippon yesoensis), Japan
Elzahara Elbaz, Mohamed Abdallah Mohamed Moustafa, Kyunglee Lee, Wessam Ahmed Mohamed Mohamed, Ryo Nakao, Michito Shimozuru, Mariko Sashika, Emad Elsayed Ahmed Younis, Sabry Ahmed El-Khodery, Toshio Tsubota
TICKS AND TICK-BORNE DISEASES, 8, 5, 802, 807, 2017, [Peer-reviewed]
English, Scientific journal - The defensive behaviour of Naja oxiana, with comments on the visual displays of cobras
Alireza Nasoori, Delavar Shahbazzadeh, Toshio Tsubota, Bruce A. Young
Herpetological Bulletin, 138, 13, 17, British Herpetological Society, 01 Dec. 2016
English, Scientific journal - Comparison of cortisol and thyroid hormones between tuberculosis-suspect and healthy elephants of Nepal
Sarad Paudel, Janine L. Brown, Sharada Thapaliya, Ishwari P. Dhakal, Susan K. Mikota, Kamal P. Gairhe, Michito Shimozuru, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 78, 11, 1713, 1716, Nov. 2016, [Peer-reviewed]
English, Scientific journal - Development and evaluation of an interferon-gamma release assay in Asian elephants (Elephas maximus)
Sarad Paudel, Marvin A. Villanueva, Susan K. Mikota, Chie Nakajima, Kamal P. Gairhe, Suraj Subedi, Nabin Rayamajhi, Mariko Sashika, Michito Shimozuru, Takashi Matsuba, Yasuhiko Suzuki, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 78, 7, 1117, 1121, Jul. 2016, [Peer-reviewed]
English, Scientific journal - Seasonal changes in the expression of energy metabolism-related genes in white adipose tissue and skeletal muscle in female Japanese black bears
Michito Shimozuru, Akiko Nagashima, Jun Tanaka, Toshio Tsubota
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY, 196, 38, 47, Jun. 2016, [Peer-reviewed]
English, Scientific journal - AN EPIZOOTIC OF EMERGING NOVEL AVIAN POX IN CARRION CROWS (CORVUS CORONE) AND LARGE-BILLED CROWS (CORVUS MACRORHYNCHOS) IN JAPAN
Daisuke Fukui, Makiko Nakamura, Tsuyoshi Yamaguchi, Makiko Takenaka, Mami Murakami, Tokuma Yanai, Hideto Fukushi, Kazumi Yanagida, Gen Bando, Keita Matsuno, Masashi Nagano, Toshio Tsubota
JOURNAL OF WILDLIFE DISEASES, 52, 2, 230, 241, Apr. 2016, [Peer-reviewed]
English, Scientific journal - Mycobacterium orygis-Associated Tuberculosis in Free-Ranging Rhinoceros, Nepal, 2015
Jeewan Thapa, Sarad Paudel, Amir Sadaula, Yogendra Shah, Bhagwan Maharjan, Gretchen E. Kaufman, Deborah McCauley, Kamal P. Gairhe, Toshio Tsubota, Yasuhiko Suzuki, Chie Nakajima
EMERGING INFECTIOUS DISEASES, 22, 3, 570, 572, Mar. 2016, [Peer-reviewed]
English - Estimation of reproductive parameters and their annual variation in brown bears of Hokkaido, Japan
Jun Moriwaki, Michito Shimozuru, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota
URSUS, 27, 2, 99, 109, 2016, [Peer-reviewed]
English, Scientific journal - Dynamics, co-infections and characteristics of zoonotic tick-borne pathogens in Hokkaido small mammals, Japan
Mohamed Abdallah Mohamed Moustafa, Kyle Taylor, Ryo Nakao, Michito Shimozuru, Mariko Sashika, Roberto Rosa, May June Thu, Annapaola Rizzoli, Toshio Tsubota
TICKS AND TICK-BORNE DISEASES, 7, 5, 922, 928, 2016, [Peer-reviewed]
English, Scientific journal - Molecular characterization and specific detection of Anaplasma species (AP-sd) in sika deer and its first detection in wild brown bears and rodents in Hokkaido, Japan
Mohamed Abdallah Mohamed Moustafa, Kyunglee Lee, Kyle Taylor, Ryo Nakao, Mariko Sashika, Michito Shimozuru, Toshio Tsubota
INFECTION GENETICS AND EVOLUTION, 36, 268, 274, Dec. 2015, [Peer-reviewed]
English, Scientific journal - Altered signaling pathway governing protein metabolism in skeletal muscle of the Japanese black bear during hibernation
Mitsunori Miyazaki, Michito Shimozuru, Toshio Tsubota
FASEB JOURNAL, 29, Apr. 2015, [Peer-reviewed]
English - Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations
Yojiro Yanagawa, Yukiko Matsuura, Masatsugu Suzuki, Shin-ichi Saga, Hideto Okuyama, Daisuke Fukui, Gen Bando, Masashi Nagano, Seiji Katagiri, Yoshiyuki Takahashi, Toshio Tsubota
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 61, 1, 61, 66, Feb. 2015, [Peer-reviewed]
English, Scientific journal - IDENTIFICATION OF INTERSPECIFIC DIFFERENCES IN PHASE II REACTIONS: DETERMINATION OF METABOLITES IN THE URINE OF 16 MAMMALIAN SPECIES EXPOSED TO ENVIRONMENTAL PYRENE
Aksorn Saengtienchai, Yoshinori Ikenaka, Shouta M. M. Nakayama, Hazuki Mizukawa, Mayu Kakehi, Nesta Bortey-Sam, Wageh Sobhy Darwish, Toshio Tsubota, Masanori Terasaki, Amnart Poapolathep, Mayumi Ishizuka
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY, 33, 9, 2062, 2069, Sep. 2014, [Peer-reviewed]
English, Scientific journal - A Genetic Method for Sex Identification of Raccoons (Procyon lotor) with Using the ZFX and ZFY Genes
Minami W. Okuyama, Michito Shimozuru, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 76, 5, 773, 775, May 2014, [Peer-reviewed]
English, Scientific journal - Molecular characterization of Mycobacterium tuberculosis isolates from elephants of Nepal
Sarad Paudel, Susan K. Mikota, Chie Nakajima, Kamal P. Gairhe, Bhagwan Maharjan, Jeewan Thapa, Ajay Poudel, Michito Shimozuru, Yasuhiko Suzuki, Toshio Tsubota
TUBERCULOSIS, 94, 3, 287, 292, May 2014, [Peer-reviewed]
English, Scientific journal - Changes in the Immunolocalization of Steroidogenic Enzymes and the Androgen Receptor in Raccoon (Procyon lotor) Testes in Association with the Seasons and Spermatogenesis
Minami W. Okuyama, Michito Shimozuru, Yojiro Yanagawa, Toshio Tsubota
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 60, 2, 155, 161, Apr. 2014, [Peer-reviewed]
English, Scientific journal - 2-1.全国のクマ分布の概要，過去との比較
佐藤喜和, 中下留美子, 坪田敏男, 中島亜美
日本クマネットワーク（編）「ツキノワグマおよびヒグマの分布域拡縮の現況把握と軋轢防止および危機個体群回復のための支援事業」報告書, 4, 13, Mar. 2014
Japanese - Areolae of the Placenta in the Antarctic Minke Whale (Balaenoptera bonaerensis)
Motoki Sasaki, Yoko Amano, Daisuke Hayakawa, Toshio Tsubota, Hajime Ishikawa, Toshihiro Mogoe, Seiji Ohsumi, Masafumi Tetsuka, Akio Miyamoto, Yutaka Fukui, Teguh Budipitojo, Nobuo Kitamura
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 60, 1, 62, 67, Feb. 2014, [Peer-reviewed]
English, Scientific journal - A relapsing fever group Borrelia sp similar to Borrelia lonestari found among wild sika deer (Cervus nippon yesoensis) and Haemaphysalis spp. ticks in Hokkaido, Japan
Kyunglee Lee, Ai Takano, Kyle Taylor, Mariko Sashika, Michito Shimozuru, Satoru Konnai, Hiroki Kawabata, Toshio Tsubota
TICKS AND TICK-BORNE DISEASES, 5, 6, 841, 847, 2014, [Peer-reviewed]
English, Scientific journal - Timing of Puberty and Its Relationship with Body Growth and Season in Male Raccoons (Procyon lotor) in Hokkaido
Minami W. Okuyama, Michito Shimozuru, Go Abe, Mariko Nakai, Mariko Sashika, Ken-Ichiro Shimada, Nobuhiro Takahashi, Daisuke Fukui, Ryohei Nakamura, Toshio Tsubota
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 59, 4, 361, 367, Aug. 2013, [Peer-reviewed]
English, Scientific journal - Hematologic and biochemical parameters of free-ranging female Nile monitors in Egypt
Mohamed Abdallah Mohamed Moustafa, Mohamed Nour-Eldin Ismail, Adel El Sayed Ahmed Mohamed, Alsagher Omran Ali, Toshio Tsubota
Journal of Wildlife Diseases, 49, 3, 750, 754, 01 Jul. 2013, [Peer-reviewed]
English, Scientific journal - Differential Tick Burdens May Explain Differential Borrelia afzelii and Borrelia garinii Infection Rates among Four, Wild, Rodent Species in Hokkaido, Japan
Kyle R. Taylor, Ai Takano, Satoru Konnai, Michito Shimozuru, Hiroki Kawabata, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 6, 785, 790, Jun. 2013, [Peer-reviewed]
English, Scientific journal - Pregnancy during hibernation in Japanese black bears: effects on body temperature and blood biochemical profiles
Michito Shimozuru, Ruriko Iibuchi, Takuro Yoshimoto, Akiko Nagashima, Jun Tanaka, Toshio Tsubota
JOURNAL OF MAMMALOGY, 94, 3, 618, 627, Jun. 2013, [Peer-reviewed]
English, Scientific journal - Differential Tick Burdens May Explain Differential Borrelia afzelii and Borrelia garinii Infection Rates among Four, Wild, Rodent Species in Hokkaido, Japan
Kyle R. Taylor, Ai Takano, Satoru Konnai, Michito Shimozuru, Hiroki Kawabata, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 6, 785, 790, Jun. 2013, [Peer-reviewed]
English, Scientific journal - Structure and Steroidogenesis of the Placenta in the Antarctic Minke Whale (Balaenoptera bonaerensis)
Motoki Sasaki, Yoko Amano, Daisuke Hayakawa, Toshio Tsubota, Hajime Ishikawa, Toshihiro Mogoe, Seiji Ohsumi, Masafumi Tetsuka, Akio Miyamoto, Yutaka Fukui, Teguh Budipitojo, Nobuo Kitamura
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 59, 2, 159, 167, Apr. 2013, [Peer-reviewed]
English, Scientific journal - Prevalence of Lyme Borrelia in Ixodes persulcatus Ticks from an Area with a Confirmed Case of Lyme Disease
Yusuke Murase, Satoru Konnai, Naftaly Githaka, Arata Hidano, Kyle Taylor, Takuya Ito, Ai Takano, Shuji Ando, Hiroki Kawabata, Toshio Tsubota, Shiro Murata, Kazuhiko Ohashi
JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 2, 215, 218, Feb. 2013, [Peer-reviewed]
English, Scientific journal - Borrelia miyamotoi Infections among Wild Rodents Show Age and Month Independence and Correlation with Ixodes persulcatus Larval Attachment in Hokkaido, Japan
Kyle R. Taylor, Ai Takano, Satoru Konnai, Michito Shimozuru, Hiroki Kawabata, Toshio Tsubota
VECTOR-BORNE AND ZOONOTIC DISEASES, 13, 2, 92, 97, Feb. 2013, [Peer-reviewed]
English, Scientific journal - Prevalence of Lyme Borrelia in Ixodes persulcatus Ticks from an Area with a Confirmed Case of Lyme Disease
Yusuke Murase, Satoru Konnai, Naftaly Githaka, Arata Hidano, Kyle Taylor, Takuya Ito, Ai Takano, Shuji Ando, Hiroki Kawabata, Toshio Tsubota, Shiro Murata, Kazuhiko Ohashi
JOURNAL OF VETERINARY MEDICAL SCIENCE, 75, 2, 215, 218, Feb. 2013, [Peer-reviewed]
English, Scientific journal - Epidemiological study of zoonoses derived from humans in captive chimpanzees
Takanori Kooriyama, Michiko Okamoto, Tomoyuki Yoshida, Toshisada Nishida, Toshio Tsubota, Akatsuki Saito, Masaki Tomonaga, Tetsuro Matsuzawa, Hirofumi Akari, Hidekazu Nishimura, Takako Miyabe-Nishiwaki
PRIMATES, 54, 1, 89, 98, Jan. 2013, [Peer-reviewed]
English, Scientific journal - Structure and Steroidogenesis of the placenta in the Antarctic Minke whale (Balaenoptera bonaerensis)
Motoki Sasaki, Yoko Amano, Daisuke Hayakawa, Toshio Tsubota, Hajime Ishikawa, Toshihiro Mogoe, Seiji Ohsumi, Masafumi Tetsuka, Akio Miyamoto, Yutaka Fukui, Teguh Budipitojo, Nobuo Kitamura
Journal of Reproduction and Development, 59, 2, 159, 167, 2013, [Peer-reviewed]
English, Scientific journal - Parasitic helminths of wild birds in the Chubu District，Japan
TERAGUSHI Tomoko, AMAKI Ryota, YOKOHATA Yasushi, ITANI Miki, TSUBOTA Toshio, SUDO Akiko, YATA Shinpei
Japanese Journal of Zoo and Wildlife Medicine, 18, 1, 33, 39, Japanese Society of Zoo and Wildlife Medicine, 2013, [Peer-reviewed]
English, Scientific journal, From 1999 to 2007, one trematode, one cestode, 23 nematode, and two acanthocephalan species were collected from the alimentary tracts of 21 wild birds belonging to 19 species from Chubu District, Japan. Eight nematode and two acanthocephalan species were identified to the species level. Porrocaecum ensicaudatum was collected from White's thrushes (Zoothera dauma) in Kanagawa and Komatsu Cities, which is a new host record for this helminth species, and the first record of this parasite in Japan. Two other new host records were also obtained: Thominx tenuissima from a Sunda scops owl (Otus lempiji) in Komatsu City, and Dispharynx emberizae from a White's thrush in Kanazawa City. - Parasitology of five primates in Mahale Mountains National Park, Tanzania
Takanori Kooriyama, Hideo Hasegawa, Michito Shimozuru, Toshio Tsubota, Toshisada Nishida, Takashi Iwaki
PRIMATES, 53, 4, 365, 375, Oct. 2012, [Peer-reviewed]
English, Scientific journal - Changes in expression of hepatic genes involved in energy metabolism during hibernation in captive, adult, female Japanese black bears (Ursus thibetanus japonicus)
Michito Shimozuru, Akari Kamine, Toshio Tsubota
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY, 163, 2, 254, 261, Oct. 2012, [Peer-reviewed]
English, Scientific journal - Effects of intramuscular administration of tiletamine-zolazepam with and without sedative pretreatment on plasma and serum biochemical values and glucose tolerance test results in Japanese black bears (Ursus thibetanus japonicus)
Akari Kamine, Michito Shimozuru, Haruki Shibata, Toshio Tsubota
AMERICAN JOURNAL OF VETERINARY RESEARCH, 73, 8, 1282, 1289, Aug. 2012, [Peer-reviewed]
English, Scientific journal - Changes in expression of hepatic genes involved in lipid metabolism during prehibernation period in captive adult female Japanese black bears (Ursus thibetanus japonicus)
Michito Shimozuru, Kamine Akari, Toshio Tsubota
CANADIAN JOURNAL OF ZOOLOGY, 90, 8, 945, 954, Aug. 2012, [Peer-reviewed]
English, Scientific journal - Effects of intramuscular administration of tiletamine-zolazepam with and without sedative pretreatment on plasma and serum biochemical values and glucose tolerance test results in Japanese black bears (Ursus thibetanus japonicus)
Akari Kamine, Michito Shimozuru, Haruki Shibata, Toshio Tsubota
AMERICAN JOURNAL OF VETERINARY RESEARCH, 73, 8, 1282, 1289, Aug. 2012, [Peer-reviewed]
English, Scientific journal - Seasonal Changes in Spermatogenesis and Peripheral Testosterone Concentration in Raccoons (Procyon lotor) in Hokkaido
Minami W. Okuyama, Michito Shimozuru, Nobuhiro Takahashi, Daisuke Fukui, Ryohei Nakamura, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 74, 6, 727, 732, Jun. 2012, [Peer-reviewed]
English, Scientific journal - Immunolocalization of steroidogenic enzymes and their expression during the breeding season in the testes of wild raccoon dogs (Nyctereutes procyonoides)
Qiang Weng, Toshio Tsubota, Mingdao Dai, Jiaju Weng, Yang Tian, Meiyu Xu, Gen Watanabe, Kazuyoshi Taya
ANIMAL SCIENCE JOURNAL, 83, 7, 535, 542, 2012, [Peer-reviewed]
English, Scientific journal - A novel relapsing fever Borrelia sp infects the salivary glands of the molted hard tick, Amblyomma geoemydae
Takano, Ai, Sugimori, Chieko, Fujita, Hiromi, Kadosaka, Teruki, Taylor, Kyle R., Tsubota, Toshio, Konnai, Satoru, Tajima, Tomoko, Sato, Kozue, Watanabe, Haruo, Ohnishi, Makoto, Kawabata, Hiroki
TICKS AND TICK-BORNE DISEASES, 3, 4, 259, 261, 2012, [Peer-reviewed]
English, Scientific journal - The study of polycyclic aromatic hydrocarbons (PAHs) and its metabolite as a biomarker for PAH exposures in wildlife animals
SAENGTIENCAHI Aksorn, IKENAKA Yoshinori, LEE Kyunglee, TSUBOTA Toshio, ISHIZUKA Mayumi
Annual Meeting of the Japanese Society of Toxicology, 39, P, 125, The Japanese Society of Toxicology, 2012
Japanese, [Introduction] Polycyclic aromatic hydrocarbons (PAHs) distribute ubiquitously as complex mixtures in the environment. Pyrene is one of PAHs that is widely used as model of PAH contamination in environment. Pyrene is metabolized by cytochrome P450s in phase I reaction then conjugated in phase II metabolism, and excreted into urine and feces. Although their metabolites are available for use in human as indicator for PAH exposure, there are still less information in wildlife. In present study, we focus on the elucidation of pyrene metabolites in wild animals. [Materials and Methods] Urine of 10 male sika deer (Cervus nippon), 1 to 5 year olds were collected from Hokkaido, Japan. All samples were extracted by Oasis WAX cartridge and they were analyzed by High performance liquid chromatography with fluorescence detector. [Results and Discussions] We could detect pyrene-1-glucuronide largely in urine. Moreover, pyrene-1-sulfate, and 1-hydroxypyrene also detected. When we compared this results with other ruminant as cattle, pyrene-1-glucuronide was main metabolites same as sika deer. Pyrene conjugate compounds were easily detected in urine. Due to observe the amount of polluted chemical as PAHs in environment, we could suggest that not only elucidate PAH concentration, but also its metabolite as 1-hydroxypyrene, pyrene 1-glucuronide, and sulfate conjugates were important to establish the appropriate biomarker for the assessment for PAH exposures in various wildlife animal species in environment. - Multilocus Sequence Typing Implicates Rodents as the Main Reservoir Host of Human-Pathogenic Borrelia garinii in Japan
Ai Takano, Minoru Nakao, Toshiyuki Masuzawa, Nobuhiro Takada, Yasuhiro Yano, Fubito Ishiguro, Hiromi Fujita, Takuya Ito, Xiaohang Ma, Yozaburo Oikawa, Fumihiko Kawamori, Kunihiko Kumagai, Toshiyuki Mikami, Nozomu Hanaoka, Shuji Ando, Naoko Honda, Kyle Taylor, Toshio Tsubota, Satoru Konnai, Haruo Watanabe, Makoto Ohnishi, Hiroki Kawabata
JOURNAL OF CLINICAL MICROBIOLOGY, 49, 5, 2035, 2039, May 2011, [Peer-reviewed]
English, Scientific journal - GENETIC CHARACTERISTICS AND ANTIMICROBIAL RESISTANCE OF ESCHERICHIA COLI FROM JAPANESE MACAQUES (MACACA FUSCATA) IN RURAL JAPAN
Keiko Ogawa, Keiji Yamaguchi, Masatsugu Suzuki, Toshio Tsubota, Kenji Ohya, Hideto Fukushi
JOURNAL OF WILDLIFE DISEASES, 47, 2, 261, 270, Apr. 2011, [Peer-reviewed]
English, Scientific journal - Evaluation of Stored Body Fat in Nuisance-killed Japanese Black Bears (Ursus thibetanus japonicus)
Atsushi Yamanaka, Makoto Asano, Masatsugu Suzuki, Toshio Mizoguchi, Toru Oi, Michito Shimozuru, Toshio Tsubota
ZOOLOGICAL SCIENCE, 28, 2, 105, 111, Feb. 2011, [Peer-reviewed]
English, Scientific journal - 獣医学における保全医学の展開－生物多様性と野生動物感染症－（緒言）
坪田敏男, 村田浩一
獣医畜産新報, 64, 1, 7-8, 32, 文永堂出版, 01 Jan. 2011
Japanese, Scientific journal - Hepatozoon sp. Infection in Hokkaido brown bears (Ursus arctos yesoensis)
Kubo, M, Chiba, E, Iibuchi, R, Tsubota, T, Sasaki M, Sakai, H, Yanai, T
Jpn.J.Zoo Wildl.Med., 15, 2, 111, 113, Dec. 2010, [Peer-reviewed] - Fecal steroid metabolites and reproductive monitoring in a female Tsushima leopard cat (Prionailurus bengalensis euptilurus)
I. Adachi, S. Kusuda, E. Nagao, Y. Taira, M. Asano, T. Tsubota, O. Doi
Theriogenology, 74, 8, 1499, 1503, Nov. 2010
English, Scientific journal - Localization of Five Steroidogenic Enzyme mRNAs in Japanese Black Bear (Ursus thibetanus japonicus) Testes During the Mating Season by In Situ Hybridization
Ruriko Iibuchi, Michito Shimozuru, Akari Kamine, Junko Nio-Kobayashi, Toshihiko Iwanaga, Toshio Tsubota
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 56, 2, 236, 242, Apr. 2010, [Peer-reviewed]
English, Scientific journal - Genetic Variation in the Harbor Seal (Phoca vitulina) and Spotted Seal (Phoca largha) Around Hokkaido, Japan, Based on Mitochondrial Cytochrome b Sequences
Emiko Nakagawa, Mari Kobayashi, Masatsugu Suzuki, Toshio Tsubota
ZOOLOGICAL SCIENCE, 27, 3, 263, 268, Mar. 2010, [Peer-reviewed]
English, Scientific journal - Immunohistochemical Localization of Steroidogenic Enzymes in the Testis of the Sika Deer (Cervus nippon) During Developmental and Seasonal Changes
Daisuke Hayakawa, Motoki Sasaki, Masatsugu Suzuki, Toshio Tsubota, Hiromasa Igota, Koichi Kaji, Nobuo Kitamura
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 56, 1, 117, 123, Feb. 2010, [Peer-reviewed]
English, Scientific journal - Muscular sarcocystosis in wild carnivores in Honshu, Japan
Masahito Kubo, Tsukasa Okano, Keiko Ito, Toshio Tsubota, Hiroki Sakai, Tokuma Yanai
PARASITOLOGY RESEARCH, 106, 1, 213, 219, Dec. 2009, [Peer-reviewed]
English, Scientific journal - Normal Sperm Morphology and Changes of Semen Characteristics and Abnormal Morphological Spermatozoa among Peri-mating Seasons in Captive Japanese Black Bears (Ursus thibetanus japonicus)
Tsukasa Okano, Tetsuma Murase, Sachiko Nakamura, Takeshi Komatsu, Toshio Tsubota, Makoto Asano
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 55, 2, 194, 199, Apr. 2009, [Peer-reviewed]
English, Scientific journal - Leptin Receptor (Ob-R) Expression in the Ovary and Uterus of the Wild Japanese Black Bear (Ursus thibetanus japonicus)
Sachiko Nakamura, Naohito Nishii, Atsushi Yamanaka, Hitoshi Kitagawa, Makoto Asano, Toshio Tsubota, Masatsugu Suzuki
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 55, 2, 110, 115, Apr. 2009, [Peer-reviewed]
English, Scientific journal - Fetal Age Estimation of Hokkaido Sika Deer (Cervus nippon yesoensis) Using Ultrasonography During Early Pregnancy
Yojiro Yanagawa, Yukiko Matsuura, Masatsugu Suzuki, Shin-ichi Saga, Hideto Okuyama, Daisuke Fukui, Gen Bandou, Seiji Katagiri, Yoshiyuki Takahashi, Toshio Tsubota
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 55, 2, 143, 148, Apr. 2009, [Peer-reviewed]
English, Scientific journal - Annual Changes in Serum Leptin Concentration in the Adult Female Japanese Black Bear (Ursus thibetanus japonicus)
Toshio Tsubota, Miho Sato, Tsukasa Okano, Sachiko Nakamura, Makoto Asano, Takeshi Komatsu, Haruki Shibata, Masayuki Saito
JOURNAL OF VETERINARY MEDICAL SCIENCE, 70, 12, 1399, 1403, Dec. 2008, [Peer-reviewed]
English, Scientific journal - Immunohistochemical localization of the estrogen receptor alpha (ER alpha) and progesterone receptor (PR) in the uterus of sika deer (Cervus nippon) during pregnancy
Yojiro Yanagawa, Yukiko Matsuura, Masatsugu Suzuki, Seiji Katagiri, Toshio Tsubota
JAPANESE JOURNAL OF VETERINARY RESEARCH, 56, 3, 139, 149, Nov. 2008, [Peer-reviewed]
English, Scientific journal - Relationships among changes of serum leptin concentration, leptin mRNA expression in white adipose tissue (WAT), and WAT fat-cell size in female Japanese black bears (Ursus thibetanus japonicus)
S. Nakamura, T. Okano, H. Shibata, M. Saito, T. Komatsu, M. Asano, M. Sugiyama, T. Tsubota, M. Suzuki
CANADIAN JOURNAL OF ZOOLOGY-REVUE CANADIENNE DE ZOOLOGIE, 86, 9, 1042, 1049, Sep. 2008
English, Scientific journal - Regional trend and tissue distribution of brominated flame retardants and persistent organochlorines in raccoon dogs (Nyctereutes procyonoides) from Japan
Tatsuya Kunisue, Nozomi Takayanagi, Tomohiko Isobe, Shin Takahashi, Susumu Nakatsu, Toshio Tsubota, Keisuke Okumoto, Sumio Bushisue, Kazuyuki Shindo, Shinsuke Tanabe
ENVIRONMENTAL SCIENCE & TECHNOLOGY, 42, 3, 685, 691, Feb. 2008, [Peer-reviewed]
English, Scientific journal - Expressions of steroidogenic enzymes mRNA in the testes of Japanese black bears (Ursus thibetanus japonicus) as revealed by in situ hybridization
Ruriko Iibuchi, Junko Nio-Kobayashi, Sachiko Nakamura, Makoto Asano, Toshihiko Iwanaga, Toshio Tsubota
BIOLOGY OF REPRODUCTION, 297, 297, 2008, [Peer-reviewed]
English - A case of chondrosarcoma in a free-flying Great Egret
Masahito Kubo, Keiya Kobayashi, Toshiaki Masegi, Hiroki Sakai, Toshio Tsubota, Makoto Asano, Miki Itani, Tokuma Yanai
JOURNAL OF WILDLIFE DISEASES, 43, 3, 542, 544, Jul. 2007, [Peer-reviewed]
English, Scientific journal - Immobilization of Japanese black bears (Ursus thibetanus japonicus) with tiletamine hydrochloride and zolazepam hydrochloride
Makoto Asano, Toshio Tsubota, Takeshi Komatsu, Atsushi Katayama, Tsukasa Okano, Sachiko Nakamura
JOURNAL OF VETERINARY MEDICAL SCIENCE, 69, 4, 433, 435, Apr. 2007, [Peer-reviewed]
English, Scientific journal - Ovulation Induction by Administration of Equine and Human Chorionic Gonadotropin in Captive Japanese Black Bears (Ursus thibetanus japonicus)"
Okano, T, Nakamura, S, Nakashita, R, Komatsu, T, Murase, T, Asano, M, Tsubota, T
Jpn. J. Zoo Wildl. Med., 12, 61, 70, 2007 - Persistent organochlorines in raccoon dogs (Nyctereutes procyonoides) from Japan: Hepatic sequestration of oxy-chlordane
Tatsuya Kunisue, Nozonu Takayanagi, Toshio Tsubota, Shinsuke Tanabe
CHEMOSPHERE, 66, 2, 203, 211, Jan. 2007, [Peer-reviewed]
English, Scientific journal - Incidence of ovulation without coital stimuli in captive Japanese black bears (Ursus thibetanus japonicus) based on serum progesterone profiles
Tsukasa Okano, Sachiko Nakamura, Rumiko Nakashita, Takeshi Komatsu, Tetsuma Murase, Makoto Asano, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 68, 10, 1133, 1137, Oct. 2006, [Peer-reviewed]
English, Scientific journal - Characteristics of frozen-thawed spermatozoa cryopreserved with different concentrations of glycerol in captive Japanese black bears (Ursus thibetanus japonicus)
Tsukasa Okano, Sachiko Nakamura, Takeshi Komatsu, Tetsuma Murase, Kiyoshi Miyazawa, Makoto Asano, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 68, 10, 1101, 1104, Oct. 2006, [Peer-reviewed]
English, Scientific journal - Characteristics of captive Japanese black bears (Ursus thibetanus japonicus) semen collected by electroejaculation with different voltages for stimulation and frozen-thawed under different conditions
T. Okano, T. Murase, C. Yayota, T. Komatsu, K. Miyazawa, M. Asano, T. Tsubota
Animal Reproduction Science, 95, 1-2, 134, 143, Sep. 2006, [Peer-reviewed]
English, Scientific journal - Immunolocalization of steroidogenic enzymes P450scc, 3 beta HSD, and P450c17 in the ovaries of wild raccoon dogs (Nyctereutes procyonoides)
Qiang Weng, Tetsuma Murase, Makoto Asano, Toshio Tsubota
JOURNAL OF VETERINARY MEDICAL SCIENCE, 68, 9, 999, 1002, Sep. 2006, [Peer-reviewed]
English, Scientific journal - 妊娠ニホンツキノワグマ(Urusus thibetanus japonicus)における体脂肪量とレプチンの繁殖への関わりの検討
NAKAMURA SACHIKO, OKANO TSUKASA, SHIBATA HARUKI, SAITO MASAYUKI, KOMATSU TAKESHI, ASANO GEN, TSUBOTA TOSHIO
J Reprod Dev, 52, Supplement, J115, 142, THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT, Aug. 2006, [Peer-reviewed]
English, ニホンツキノワグマ（Ursus thibetanus japonicus）（以下、クマ）は冬眠中に出産・哺育を行うため、冬眠前時期の脂肪蓄積が繁殖に影響するとされる。レプチンは主に白色脂肪組織（WAT）より分泌される抗肥満ホルモンとして知られるが、ヒトや齧歯類では着床や妊娠に関わる働きを持つとされる。演者らはこのレプチンに注目し、妊娠雌グマにおける着床時期（11月下旬～12月上旬）前後の体脂肪量とレプチン産生量を検討した。秋田県阿仁クマ牧場における妊娠雌グマ5頭を用いた。9月から翌1月までおよそ1ヶ月に1回、麻酔下で体重・体脂肪率測定、採血および脂肪採取を行った。体脂肪率はRJL Systems Quantum Xを用いて測定し、アメリカクロクマに対する換算式を適用した。ELISAにより血中レプチン濃度を測定した。WATからtotal RNAを抽出し、ワンステップリアルタイムRT-PCRでレプチンmRNA発現を定量した。体重は10月から、体脂肪量は9月下旬から有意に上昇し、ともに11月下旬に最高値を示した後、冬眠に入ってからは徐々に減少した。両者の増減の相関は0.98であった。血中レプチン濃度は、10月まで緩やかに増加し、11月中旬・下旬に有意に上昇した(p<0.05)後、減少した。WATにおけるレプチンmRNA発現量は11月下旬および1月中旬に上昇したが、有意差は認められなかった。体重増減量は体脂肪量を反映していると考えられた。血中レプチン濃度とWATレプチンmRNA発現量に明確な関連はなかったが、共に11月に上昇が認められ、WATがこの時期のレプチン産生源の一つである可能性は高い。また、脂肪蓄積時期にわたって血中レプチン濃度が上昇したことから、産生されたレプチンは摂食抑制やエネルギー代謝亢進作用ではなく、むしろ着床の誘起など、繁殖に関与していると考えられた。今後レセプターの発現など、作用機序について検討する必要がある。 - Seasonal changes in immunolocalization of inhibin/activin subunits and testicular activity in wild male raccoon dogs (Nyctereutes procyonoides)
Qiang Weng, Mohamed S. Medan, Meiyu Xu, Toshio Tsubota, Gen Watanabe, Kazuyoshi Taya
JOURNAL OF REPRODUCTION AND DEVELOPMENT, 52, 4, 503, 510, Aug. 2006, [Peer-reviewed]
English, Scientific journal - PCDDs, PCDFs, and coplanar PCBs in wild terrestrial mammals from Japan: Congener specific accumulation and hepatic sequestration
Tatsuya Kunisue, Michio X. Watanabe, Hisato Iwata, Toshio Tsubota, Fumio Yamada, Masatoshi Yasuda, Shinsuke Tanabe
Environmental Pollution, 140, 3, 525, 535, Apr. 2006
English, Scientific journal - Changes in serum inhibin levels and immunolocalization of inhibin/activin subunits during the breeding season in the wild male Japanese black bear (Ursus thibetanus japonicus)
Qiang Weng, Mohamed S. Medan, Tsukasa Okano, Tetsuma Murase, Toshio Tsubota, Meiyu Xu, Gen Watanabe, Kazuyoshi Taya
ENDOCRINE, 29, 2, 345, 350, Apr. 2006, [Peer-reviewed]
English, Scientific journal - Reproductive characteristics of brown bears on the Oshima Peninsula, Hokkaido, Japan
T Mano, T Tsubota
JOURNAL OF MAMMALOGY, 83, 4, 1026, 1034, Nov. 2002, [Peer-reviewed]
English, Scientific journal - Sequence comparison of the dopamine receptor D4 Exon III repetitive region in several species of the order Carnivora
M Inoue-Murayama, N Matsuura, Y Murayama, T Tsubota, T Iwasaki, H Kitagawa, S Ito
JOURNAL OF VETERINARY MEDICAL SCIENCE, 64, 8, 747, 749, Aug. 2002, [Peer-reviewed]
English, Scientific journal - Analysis of Causes of Bark Stripping by the Japanese Black Bear (Ursus thibetanus japonicus).
Yoshida Y, Hayashi S, Horiuchi M, Tsubota T, Murase T, Okano T, Sato M, Yamamoto K
Mammalian Science, 42, 1, 35, 43, The Mammal Society of Japan, 2002, [Peer-reviewed]
Japanese, In order to analyze the cause of bark stripping by Japanese black bears and to develop effective methods to prevent this damage, we examined food habits and body condition of the bear from 1998 to 2000 in Neo Village, Gifu Prefecture, Japan. Fecal analysis indicated that more conifer sapwood was consumed in 1999 and 2000 than in 1998. In contrast, a percentage of Gray's bird cherries (Prunus grayana) by dry weight was lower in 1999 and 2000 than in 1998. The dietary condition of bears expressed by serum urea nitrogen concentrations and blood hemoglobin concentrations in 1999 and 2000 was worse than that in 1998. These results suggest that the damage tends to happen when food production and nutritional availability in the stands is poor. If there is more food for the bears to consume, the damage in the stands should be lighter. Vegetation similar to that of the forest edge, where heliophytes grow, may be desirable. By diversifying the forest composition, introducing herbaceous plants that require more sunlight on forest floor through use of a regeneration management prescription, and actively growing preferred Japanese black bear foods in the forest environment, it may be possible to prevent bark stripping damage to plantation trees. - Observation of Sexual Behavior of Captive Japanese Black Bears, Ursus tibetanus japonicus
YAMAMOTO Kaori, TSUBOTA Toshio, KITA Isao
The Japanese journal of animal reproduction, 44, 5, j13, j18, THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT, 01 Jun. 1998
Japanese, Sexual behavior of 22 male and 17 female Iapanese black bears, Ursus thibetanus japonicus, in Ani Bear Park was observed for 40 days from June 22 to July 31, 1996. The mating season in this bear park extended from mid-June to early August. Their mating pattern was regarded as promiscuous type. The mating period of females varied from 12 to 35 days widely among animals. The mating period contained estrous and non-estrous period, which occurred irregulaly. Male mating behavior was suspected to accompany female estrus. Total mating days of male bears aged 4-5 years old were less than those of older males. In males over 6 years old, males weighed over 80 kg had more total mating days than smaller males. These suggest that, under captive conditions with high density, some subordinate males, even if they had been matured, were probably unable to have opportunity to breed, due to social hierachy related to the age and body weight of male Japanese black bears. - 超音波断層診断および脱脂乳中プロジェステロン測定による乳牛分娩後の生殖器の修復と受胎成績
三宅 浩文, 大島 由美, 坪田 敏男
日本獣医師会雑誌, 46, 1, 12, 18, (公社)日本獣医師会, Jan. 1993
Japanese - Growth, Sexual Dimorphism, and Geographical Variation of Skull Dimensions of the Brown Bear Ursus arctos in Hokkaido
OHDACHI Satoshi, AOI Toshiki, MANO Tsutomu, TSUBOTA Toshio
Journal of the Mammalogical Society of Japan, 17, 1, 27, 47, 一般社団法人 日本哺乳類学会, 1992, [Peer-reviewed]
English, The growth, sexual dimorphism, and geographical variation in skulls of 596 brown bears (<i>Ursus arctos</i>) hunted in Hokkaido, Japan from 1971 to 1986 were investigated. Most cranial traits continued to increase after the age of sexual maturity, and in particular skulls became progressively wider with age. Skulls of males, even those of cubs and yearlings, were larger than those of females, and the difference became significant after two years of age. Skull dimensions tended to increase from south to north, in Hokkaido, and bears from the north-eastern region possessed higher brain cases and longer mandibles relative to skull length and width, than those in the southern region.<br> - CORPORA-ALBICANTIA AND PLACENTAL SCARS IN THE HOKKAIDO BROWN BEAR
T TSUBOTA, H KANAGAWA, T MANO, T AOI
BEARS - THEIR BIOLOGY AND MANAGEMENT, 8, 125, 128, 1990, [Peer-reviewed]
English, International conference proceedings
Other Activities and Achievements
- Seasonal changes in the species composition of ticks attached sika deer (Cervus nippon yesoensis)
清水広太郎, 山中正実, 伊藤源太, 中尾亮, 佐鹿万里子, 下鶴倫人, 坪田敏男, 日本生態学会大会講演要旨(Web), 70th, 2023 - 北海道のエゾシカとヒグマにおけるマダニ寄生状況の比較:寄生数に影響を与える要因は何か?
清水広太郎, 中尾亮, 下鶴倫人, 釣賀一二三, 白根ゆり, 山中正実, 伊藤源太, 新庄康平, 梅村佳寛, 村上拓弥, 伊集院彩暮, 坪田敏男, 日本哺乳類学会大会プログラム・講演要旨集, 2023, 2023 - Risk assessment of tick-borne virus transmission from ticks using raccoon as a sentinel
伊藤萌林, 松野啓太, 南川未来, 南川未来, 重野麻子, 有泉拓馬, 伊藤哲治, KOVBA Anastasiia, 沼田栄花, 大森亮介, 尾針由真, 中尾亮, 下鶴輪人, 坪田敏男, 佐鹿万里子, 日本野生動物医学会大会・講演要旨集, 29th, 2023 - 北海道のエゾシカに寄生するシカシラミバエの病原体の保有状況
清水広太郎, 下鶴倫人, 佐鹿万里子, 中尾亮, 坪田敏男, 日本獣医学会学術集会講演要旨集, 165th (CD-ROM), 2022 - Individual and regional variation in the diet of brown bears in the Shiretoko Peninsula.
神保美渚, 白根ゆり, 梅村佳寛, 新庄康平, 中西将尚, 石名坂豪, 宇野裕之, 佐鹿万里子, 坪田敏男, 下鶴倫人, 日本生態学会大会講演要旨(Web), 68th, 2021 - 北海道斜里町においてエゾヒグマより採集されたタカサゴキララマダニの一例
下鶴 倫人, 新庄 康平, 崎山 智樹, 小方 昌平, 草木迫 浩大, 木下 豪太, Mohamed Wessam Mohamed Ahmed, Moustafa Mohamed Abdallah Mohamed, 松野 啓太, 伊東 拓也, 野中 成晃, 佐鹿 万里子, 坪田 敏男, 中尾 亮, 日本獣医学会学術集会講演要旨集, 163回, 327, 327, Oct. 2020
(公社)日本獣医学会, Japanese - Brown bear hair growth and application for the ecological study on wild brown bears
神保美渚, 松本直也, 坂元秀行, 石名坂豪, 柳川洋二郎, 鳥居佳子, 白根ゆり, 佐鹿万里子, 坪田敏男, 下鶴倫人, 日本生態学会大会講演要旨(Web), 67th, 2020 - Symposium20-4
宮﨑 充功, 下鶴 倫人, 坪田 敏男, Japanese Journal of Physical Fitness and Sports Medicine, 69, 1, 89, 89, 2020
The Japanese Society of Physical Fitness and Sports Medicine, Japanese - 動物たちの特殊な生存戦略を科学する:冬眠・休眠動物を対象とした研究展開 冬眠中のクマにおけるエネルギー代謝および体温調節機構
坪田 敏男, 日本獣医学会学術集会講演要旨集, 162回, 282, 282, Aug. 2019
(公社)日本獣医学会, Japanese - 夏期の食物環境の変動がヒグマの栄養状態に与える影響の解明
白根ゆり, 山中正実, 中西將尚, 石名坂豪, 神保美渚, 佐鹿万里子, 坪田敏男, 下鶴倫人, 日本哺乳類学会大会プログラム・講演要旨集, 2019, 2019 - 北海道立自然公園野幌森林公園におけるアライグマ(Procyon lotor)およびエゾタヌキ(Nyctereutes procyonoides albus)の食性と生息地比較に関する研究
尾崎彩, 佐鹿万里子, 下鶴倫人, 坪田敏男, 日本哺乳類学会大会プログラム・講演要旨集, 2018, 2018 - キツネ用駆虫薬ベイトを用いたエキノコックス症対策-小面積地域への適用(2)-
浦口宏二, 入江隆夫, 孝口裕一, 八木欣平, 佐鹿万里子, 坪田敏男, 日本哺乳類学会大会プログラム・講演要旨集, 2017, 2017 - キツネ用駆虫薬ベイトを用いたエキノコックス症対策―小面積地域への適用―
浦口宏二, 入江隆夫, 孝口裕一, 八木欣平, 稲森梓, 下鶴倫人, 坪田敏男, 日本哺乳類学会大会プログラム・講演要旨集, 2016, 101, 23 Sep. 2016
Japanese - Host-Vector-Pathogen Interactions of Tick-Borne Diseases in Hokkaido Wildlife
坪田 敏男, 日本野生動物医学会誌 = Japanese journal of zoo and wildlife medicine, 21, 3, 47, 51, Sep. 2016
日本野生動物医学会, Japanese - Tuberculosis in Elephants : A Zoonotic Disease at the Human-Elephant Interface (特集 野生動物医学の新展開"Disease Ecology"とはどのような学問分野か : 第21回日本野生動物医学会大会 日本野生動物医学会IWMC2015連携公開シンポジウム)
PAUDEL Sarad, 坪田 敏男, 日本野生動物医学会誌 = Japanese journal of zoo and wildlife medicine, 21, 3, 65, 69, Sep. 2016
日本野生動物医学会, English - エキノコックス症対策におけるベイト(駆虫薬入りエサ)の小面積散布について
浦口宏二, 孝口裕一, 入江隆夫, 稲森梓, 下鶴倫人, 坪田敏男, 八木欣平, 日本獣医学会学術集会講演要旨集, 159th, 341, 341, 30 Aug. 2016
(公社)日本獣医学会, Japanese - 北海道におけるアライグマの遺伝子型の地理的分布に関する研究
奥山みなみ, 下鶴倫人, 中井真理子, 藤井啓, 山口英美, 島田健一郎, 池田透, 坪田敏男, 日本獣医学会学術集会講演要旨集, 159th, 515, 515, 30 Aug. 2016
(公社)日本獣医学会, Japanese - 動物園獣医学の現状と課題 動物園動物の福祉向上を目指して 大学における動物園獣医学教育の現状と課題
坪田 敏男, 北海道獣医師会雑誌, 60, 8, 439, 439, Aug. 2016
(公社)北海道獣医師会, Japanese - クマの冬眠と繁殖の生理・内分泌メカニズム
坪田 敏男, 日本神経麻酔集中治療学会プログラム・抄録集, 20回, 22, 22, Jul. 2016
日本神経麻酔集中治療学会, Japanese - 南アジアはMycobacterium orygisの風土病地域である(South Asia is an endemic region for Mycobacterium orygis)
Thapa Jeewan, 中島 千絵, Rahim Zeaur, Paudel Sarad, Shah Yogendra, Maharian Bhagwan, Poudel Ajay, Gairhe Kamal Prasad, 坪田 敏男, 鈴木 定彦, 日本細菌学雑誌, 71, 1, 159, 159, Feb. 2016
日本細菌学会, English - 知床半島におけるヒグマの移動分散様式の解明
白根ゆり, 山中正実, 中西將尚, 石名坂豪, 能勢峰, 葛西真輔, 白柳正隆, 増田泰, 釣賀一二三, 間野勉, 藤本靖, 長田雅裕, 佐鹿万里子, 坪田敏男, 下鶴倫人, 日本哺乳類学会大会プログラム・講演要旨集, 2016, 2016 - 飼育下ツキノワグマにおける冬眠前および冬眠中の体温および心拍数の変化
坪田敏男, 鈴木信吾, 宮城太輔, 山崎晃司, 佐鹿万里子, 下鶴倫人, 日本野生動物医学会大会・講演要旨集, 22nd, 2016 - Tuberculosis in Elephants: A Zoonotic Disease at the Human-Elephant Interface
Sarad PAUDEL, TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 21, 3, 65, 69, 2016Tuberculosis (TB) in elephants is a re-emerging disease predominantly caused by Mycobacterium tuberculosis, a human type of TB. Elephant to human TB transmission has been reported from several zoological facilities which have public health implications. Culture of respiratory samples obtained using a trunk wash procedure is regarded as the gold standard for TB diagnosis in elephants; however, this technique has many limitations. Serological methods have been developed and are widely used for TB testing in elephants in zoos around the world and elephant facilities in Asian elephant range countries. Regular TB screening of elephants and their handlers should be performed; infected elephants and handlers should be segregated and treated with anti-TB drugs according to established treatment regimens. Screening, segregation, and treatment will aid in the prevention of TB transmission between species and will contribute to the conservation of endangered wild elephants by mitigating TB spread at the captive-wild interface.
, Japanese Society of Zoo and Wildlife Medicine, Japanese - 【感染症 いま何が起きているのか 基礎研究、臨床から国際支援まで】(第2章)感染症研究のいま メカニズムから予防・治療まで マクロ生物学からのアプローチ 生物多様性と感染症 生物多様性保全による生態系での感染リスク低下
坪田 敏男, 実験医学, 33, 17, 2815, 2820, Nov. 2015
(株)羊土社, Japanese - ツキノワグマにおける冬眠期の皮下体温、腹腔内体温および活動量測定の試み
鈴木 信吾, 山崎 晃司, 佐鹿 万里子, 下鶴 倫人, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 158回, 449, 449, Aug. 2015
(公社)日本獣医学会, Japanese - 北海道のエゾタヌキとアライグマにおけるイヌジステンパーウイルス感染に関する疫学調査
佐鹿 万里子, 阿部 豪, 郡山 尚紀, 中井 真理子, 島田 健一郎, 前田 健, 下鶴 倫人, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 158回, 450, 450, Aug. 2015
(公社)日本獣医学会, Japanese - Behavioral features and the genetic structure of the brown bear population in Hokkaido
Tsubota Toshio, Yamanaka Masami, Honyurui Kagaku (Mammalian Science), 55, 1, 87, 88, 2015
The Mammal Society of Japan, Japanese - One Health and Conservation Medicine－Development of the Japanese Society of Zoo and Wildlife Medicine for the Past 20 Years－
TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 20, 2, 27, 33, 2015Japanese Society of Zoo and Wildlife Medicine (JSZWM) which was founded in 1995 meets 20-year anniversary and is developing with energetic activity such as establishment of diploma qualification foundation, annual student seminar courses, assignment of experts for infectious disease control in wildlife, support of the Asian Society of Conservation Medicine, and formulation of some guidelines for wildlife conservation and ethics. There have been many socially-concerned events related with wildlife, including effects of endocrine disruptors, outbreak of lead poisoning in raptors, mass intrusion of bears into residential area, re-introduction of endangered birds such as Japanese crested ibis and white stork, highly pathogenic avian influenza outbreak. As an academic field responding to these problems, conservation medicine develops and becomes of an inter-disciplinary importance as well as One Health concepts. This field will be necessary more than nowadays to contribute conservation of biodiversity, encouraging the JSZWM development with relation to other organizations.
, Japanese Society of Zoo and Wildlife Medicine, Japanese - 2007年以前の国内野生動物における重症熱性血小板減少症候群ウイルス(SFTSV)に対する抗体調査
堀田明豊, 木村昌伸, 坪田敏男, 中村幸子, 片山敦司, 中下留美子, 猪島康雄, 鈴木道雄, 今岡浩一, 棚林清, 藤田修, 山本美江, 宇田晶彦, 森川茂, 日本獣医学会学術集会講演要旨集, 157th, 394, 394, 11 Aug. 2014
(公社)日本獣医学会, Japanese - ネコ目動物3種における尿道カテーテル挿入による精子採取
高江洲昇, 伊藤真輝, 菅原里沙, 柳川洋二郎, 永野昌志, 佐鹿万里子, 下鶴倫人, 坪田敏男, 日本獣医学会学術集会講演要旨集, 157th, 547, 547, 11 Aug. 2014
(公社)日本獣医学会, Japanese - 知床半島ルシャ地区におけるヒグマの繁殖様式に関する研究
下鶴 倫人, 森脇 潤, 山中 正実, 中西 將尚, 石名坂 豪, 葛西 真輔, 能勢 峰, 増田 泰, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 157回, 548, 548, Aug. 2014
(公社)日本獣医学会, Japanese - 北海道のsika deerおよびHaemaphysalis属ダニより検出されたRF Borrelia属(A RF Borrelia sp. found among wild sika deer and Haemaphysalis ticks in Hokkaido)
李 景利, 高野 愛, Taylor Kyle, 佐鹿 万里子, 下鶴 倫人, 今内 覚, 川端 寛樹, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 157回, 548, 548, Aug. 2014
(公社)日本獣医学会, English - クマ類全国分布の最前線 (The JBN Times)
佐藤 喜和, 中下 留美子, 坪田 敏男, Bears Japan, 14, 3, 5, 10, Mar. 2014
[日本クマネットワーク事務局], Japanese - Egg Trapと箱わなによるアライグマの捕獲効率の比較
佐鹿万里子, 阿部豪, 中井真理子, 島田健一郎, 坪田敏男, 日本哺乳類学会大会プログラム・講演要旨集, 2014, 2014 - 腎臓周囲脂肪および大腿骨骨髄内脂肪を用いたヒグマの栄養状態評価
森真理子, 佐鹿万里子, 下鶴倫人, 坪田敏男, 間野勉, 日本哺乳類学会大会プログラム・講演要旨集, 2014, 2014 - 国内に潜在すると考えられる新興回帰熱に関する疫学調査研究
高野愛, 川端寛樹, 大久保(佐藤)梢, 中尾稔, 伊東拓也, TAYLOR Kyle, 李景利, 坪田敏男, 今内覚, 吉村英紘, 豊間根耕地, 村田史郎, 大橋和彦, 日本獣医学会学術集会講演要旨集, 156回, 304, 304, Aug. 2013
(公社)日本獣医学会, Japanese - The status of newly developed wildlife telemetry systems
AOI Toshiki, YAMAZAKI Koji, TSUBOTA Toshio, Honyurui Kagaku (Mammalian Science), 53, 1, 206, 208, 30 Jun. 2013
The Mammal Society of Japan, Japanese - 北海道の野生下におけるボレリア種の維持、小型哺乳類とダニの関係について(On the maintenance of Borrelia spp. among wildlife in Hokkaido: the relationship between small mammals and ticks)
カイル・テイラー, 川端 寛樹, 今内 覚, 下鶴 倫人, 高野 愛, 坪田 敏男, 衛生動物, 64, 2, 112, 112, Jun. 2013
日本衛生動物学会, English - 回帰熱病原体Borrelia miyamotoiの検出法の確立・検証,およびIxodes属ダニからの病原体検出への応用.
高野愛, 佐藤梢, 中尾稔, 伊東拓也, TAYLOR Kyle, 今内覚, 坪田敏男, 高田伸弘, 川端寛樹, 衛生動物, 64, 2, 113, 113, Jun. 2013
日本衛生動物学会, Japanese - 【人と動物の共通感染症最前線10】 日本のげっ歯類におけるハンタウイルス感染の血清疫学調査とエゾヤチネズミが保有するHokkaidoウイルスの分離
苅和 宏明, 尾崎 由佳, 真田 崇弘, 池中 良徳, 石塚 真由美, 坪田 敏男, 好井 健太朗, 吉松 組子, 有川 二郎, 高島 郁夫, 獣医畜産新報, 66, 4, 262, 264, Apr. 2013
文永堂出版(株), Japanese - Recent Status of Bear Habitation and Damage by Bears
TSUBOTA Toshio, Journal of the Japan Veterinary Medical Association, 66, 2, 131, 137, 20 Feb. 2013
近年，クマが人里に出没する問題が頻繁にマスコミに取り上げられるようになった。このようにクマが日本中を騒がすようになったのは，おそらく2004年のツキノワグマ大量出没が事の始まりだったと思われる。ときに，通学路で自転車に乗った中学生が襲われたり，ただしゃがんで庭仕事をしているところを背後から襲われたり，海辺で釣りをしていたら釣った魚をクマに持っていかれたなどといった事件が起きた。人里へのクマの出没は，すでに一種の社会問題になっており，市民の関心も非常に高い。クマに対する恐怖心が膨らむ一方で，駆除されるクマに同情を寄せる市民も少なくない。人間が山を荒らした結果，クマが人里に出てくるのだと主張する人たちは，何とかクマを救いたいと声をあげている。さまざまな感情や意見が交錯する中，科学的な情報に基づいた適切な保護管理の実現は，いまだほど遠い状況にある。北米で行われているような，行政主体の保護管理システムを早く日本にも確立・定着することが肝心である。そのためには，大学でクマ対応ができる人材を育成し，保護管理を実施するポジションに専門家を配置する自治体が増えていくことが望まれる。本稿では，最近のクマの生息動向と被害状況について，彼らの生態を交えて解説していきたい。, Japan Veterinary Medical Association, Japanese - アライグマ精巣組織における精子形成調節機構の解析：ステロイド代謝およびテストステロン感受性との関連性の解明
奥山 みなみ, 下鶴 倫人, 坪田 敏男, 日本繁殖生物学会 講演要旨集, 106, P, 6-P-6, 2013
【目的】一般に季節繁殖動物の雄では，非繁殖期には血中テストステロン(T)濃度が低く精子形成機能が低下する。しかし，冬に交尾期を持つアライグマ(Procyon lotor)では，非繁殖期である夏にT濃度が低いにも関わらず精子形成が活発な個体がいることが報告されている。このことは，T産生と精子形成が異なる機構により調節されている可能性を示している。本研究は，ステロイド代謝酵素(P450scc，P450c17，3βHSD，P450arom) およびアンドロジェン受容体(AR)発現の季節差と個体差を解析することにより，T産生および感受性と精子形成との関連性を明らかにすることを目的とした。【方法】冬期個体(n=4)，夏期に活発な精子形成がみられた個体(n=4)および夏期に精子形成がみられなかった個体(n=6)について，血漿中T濃度をELISA法にて測定した。また，精巣組織切片の免疫染色により上記4酵素とARの発現部位を特定し，3群間での発現強度を比較した。【結果・考察】精巣組織において，P450sccおよびP450c17はLeydig細胞，3βHSDはLeydig細胞およびSertoli細胞，P450aromはLeydig細胞，Sertoli細胞および一部の精子細胞で発現が確認された。夏期個体の平均T濃度は冬期個体に比べ低値であった(夏：0.2ng/ml，冬: 2.3ng/ml)。P450sccおよびP450c17は3群間で発現強度に差は見られなかったが，3βHSDは冬期個体に比べ夏期個体で発現が弱かったことから，T産生には3βHSDの発現変化が関係していることが示唆された。またP450aromおよびARは夏期に精子形成がみられた個体では冬期個体と同程度に発現したが，夏期に精子形成がみられない個体では極めて発現が弱かったことから，夏期の精子形成維持にはP450aromおよびARが関わっており，それぞれ精子の成熟機構および精巣組織におけるテストステロン感受性の維持に関係していることが示唆された。, 日本繁殖生物学会, Japanese - 北海道のエゾタヌキにおけるイヌジステンパーウイルス感染に関する疫学調査
佐鹿 万里子, 阿部 豪, 郡山 尚紀, 前田 健, 坪田 敏男, 霊長類研究 Supplement, 29, 256, 256, 2013
【背景】近年，エゾタヌキ Nyctereutes procyonoides albusの地域個体数減少が報告されており，この原因として疥癬やジステンパーなどの感染症や外来種アライグマの影響が考えられているが，その原因は明らかとなっていない．そこで本研究では，エゾタヌキ（以下，タヌキとする）を対象に，ホンドタヌキで集団感染死が報告されているイヌジステンパーウイルス（Canine distemper virus：以下，CDVとする）について疫学調査を行った．
【材料と方法】調査地域は，2002～ 2004年に重度疥癬タヌキが捕獲され，さらにタヌキ個体数減少も確認されている北海道立野幌森林公園を選定した．2004～ 2012年に同公園内で捕獲されたタヌキ 111頭において麻酔処置下で採血を行うと同時に，マイクロチップの挿入と身体検査を行った．血液から血漿を分離し，CDVに対する中和抗体試験を行った．
【結果】CDVに対する抗体保有率は 2004年：44.4％，2005年：8.3%，2006年：14.3%，2007年：11.1％，2008年：7.7％，2009年：54.5％，2010年：8.3%，2011年：0%，2012年： 0%であった．また，同公園内では 2003年に 26頭のタヌキが確認されたが，2004年には 9頭にまで激減し，その後，2010年までは 10頭前後で推移していた．しかし，2011年は 18頭，2012年には 16頭のタヌキが確認され，タヌキ個体数が回復傾向を示した．
【考察】抗体保有率は 2004年および 2009年に顕著に高い値を示したことから，同公園内では 2004年と 2009年に CDVの流行が起きた可能性が示唆された．また，2002～ 2004年には，同公園内で疥癬が流行していたことが確認されているため，同公園内では CDVと疥癬が同時期に流行したことによってタヌキ個体数が減少したと考えられた．, 日本霊長類学会, Japanese - 知床半島ルシャ地域におけるヒグマの血縁関係解析
森脇 潤, 下鶴 倫人, 山中 正実, 中西 將尚, 永野 夏生, 増田 泰, 藤本 靖, 坪田 敏男, 霊長類研究 Supplement, 29, 242, 242, 2013
動物が高密度に生息する地域において，集団の血縁関係を明らかにすることは，その地域を利用する個体毎の繁殖，行動および分布様式を解明する上で重要である．そこで知床半島ルシャ地区におけるヒグマの繁殖，行動および移動分散様式を解明することを目的として，個体識別調査および集団遺伝学的解析により，個体間の血縁関係を解析した．材料は，同地区でヘアートラップ，ダートバイオプシー等により収集された遺伝子材料 51頭（雄 21頭，雌 30頭）分と，周辺地区（斜里，羅臼および標津地区）で学術捕獲あるいは捕殺個体 164頭分の遺伝子材料および各種メディアの情報を利用した．遺伝子解析には 22座位のマイクロサテライト領域を利用した．その結果，ルシャ地区には 15頭の成獣メスと，その子供からなる集団が生息しており，血縁は大きく２つの母系集団に分かれていた．また，最大で 3世代が共存していた．ルシャ地区で繁殖に関与する父親は，現在までに 5頭認められ，近親交配やマルチプルパタニティーが存在することが明らかになった．ルシャ地区を利用する個体の中で，5頭の亜成獣オスが斜里および羅臼地区側へ移動分散して捕殺されていることも明らかになった．このように，高密度に生息する知床半島ルシャ地区でのヒグマ集団の血縁関係を明らかにすることは，従来の野外調査では明らかには出来ないヒグマの繁殖システムの解明に寄与するだけではなく，繁殖個体の周辺地域への移動分散を明らかにすることができる．尚，本研究はダイキン工業寄附事業 「知床半島先端部地区におけるヒグマ個体群の保護管理，及び，羅臼町住民生活圏へ与える影響に関する研究」の一環として行われたものである．, 日本霊長類学会, Japanese - ヒグマにとって厳しかった夏 -2012年、知床半島での事例-
下鶴 倫人, 坪田 敏男, 森脇 潤, 山中 正実, 西將 尚, 石名 坂豪, 葛西 真輔, 白柳 正隆, 能勢 峰, 増田 泰, 霊長類研究 Supplement, 29, 92, 92, 2013
2012年知床半島では，夏期に極度に痩せたヒグマがメディアで報道され話題となるなど，夏期の食物不足の深刻さが窺える状況であった．斜里町・羅臼町におけるヒグマの目撃数・駆除数は例年の約2倍近くとなり，特に 8月に目撃数・駆除数がピークとなったことは例年にない特徴であった．また，親とはぐれたであろう当歳子や，餓死とみられる死体が夏期に複数確認されたことは，例年以上に夏期の死亡率が高かったことを推測させた．これらの原因として，カラフトマスの遡上が 8月末まで遅れたことや，ハイマツ等の実りが悪かったことが考えられるが，因果関係の有無については今後検証する必要がある．知床半島先端付近に位置するルシャ地区において実施しているヒグマ個体追跡調査においても同様の状況が見てとれた．同地区に定住している成獣メスの体型を追跡すると，7月初旬までは多くの個体が軽度に肥満していたが，8月に入ると急激に削痩し，そのうちの一頭は 8月末に死体で発見された．カラフトマスの遡上が始まった 9月以降は体型が回復し，10月には全個体が充分に肥満した状態となった．成獣メスの連れ子数を追跡した結果，当歳もしくは一歳齢の子を連れた個体（全 8頭）のすべてが 7月から 9月にかけて子の数を減らしたことが明らかとなった．2011年ではこのような事例は全 9頭中 1例のみしか認められなかったことから，2012年の連れ子の離別率は顕著に高かったといえる．さらに同地区ではこれまで多くの個体が 2年周期の繁殖サイクルを示す傾向にあったが，2012年は一歳齢を連れた成獣メスが例年に比べて多く，3年周期の繁殖サイクルを示す傾向にあった．このようなことから，知床半島先端部ではカラフトマスをはじめとした夏期の食物の豊凶が，ヒグマの生存率や繁殖率に大きく影響を与えていることが示唆された．尚，本研究はダイキン工業寄付事業の一環として行われたものである．, 日本霊長類学会, Japanese - 尿道カテーテル法を応用したニホンザルの精液採取
高江洲昇, 柳川洋二郎, 永野昌志, 兼子明久, 今井啓雄, 岡本宗裕, 下鶴倫人, 坪田敏男, 日本野生動物医学会大会・講演要旨集, 19th, 72, 2013
Japanese - エゾシカの発達および性成熟過程における卵胞形成と卵胞でのステロイド合成能
小林すみよ, 柳川洋二郎, 坪田敏男, 永野昌志, 日本野生動物医学会大会・講演要旨集, 19th, 95, 2013
Japanese - カメキララマダニより検出された新種回帰熱ボレリアの経ステージ感染様式~ボレリア属細菌の進化の軌跡を探る~
高野愛, 杉森千恵子, 藤田博己, 角坂照貴, TAYLOR Kyle, 坪田敏男, 今内覚, 田島朋子, 佐藤梢, 渡邉治雄, 大西真, 川端寛樹, 大原綜合病院年報, 52, 106, 107, Dec. 2012
(一財)大原記念財団, Japanese - カメキララマダニより検出された回帰熱群ボレリアの経ステージ感染様式
高野愛, 杉森千恵子, 藤田博己, 角坂照貴, TAYLOR Kyle, 坪田敏男, 今内覚, 田島朋子, 佐藤梢, 渡邉治雄, 大西真, 川端寛樹, 日本獣医学会学術集会講演要旨集, 154回, 270, 270, Aug. 2012
(公社)日本獣医学会, Japanese - How to Tackle The Management of Infectious Diseases in Wild Animals
TAKAMI Kazutoshi, WATANABE Yukiko, TSUBOTA Toshio, FUKUI Daisuke, ONUMA Manabu, YAMAMOTO Mai, MURATA Koichi, Jpn J Zoo Wildl Med, 17, 2, 33, 42, 01 Jun. 2012
Japanese - Allometric growth and morphology of Steller sea lion fetuses
JONO MANAMI, KOBAYASHI YUMI, ASANUMA TAKETOSHI, ASANUMA TAKETOSHI, TSUBOTA TOSHIO, SAKURAI YASUNORI, 北海道大学水産科学研究い報, 62, 1, 1, 7, 28 Mar. 2012
胎子が出生する際の発達段階は,進化の過程で変化し,種によって多様である。新生子はその成長形態によって,早成性(precocial)と晩成性(altricial)に区別される。海生哺乳類は,総じて早成性である。本研究では,トド胎子の成長様式および形態的特徴の知見を得ることを目的とし,成長および相対成長解析,外部形態の観察,ならびに内部器官観察を行った。そして,出生後の水中と陸上の生息環境への適応という観点から,胎子の成長について考察した。, 北海道大学大学院水産科学研究科, Japanese - ダニによる寄生および感染症と生物多様性保全 北海道における齧歯類の動態とボレリア細菌種の感染率(Rodent dynamics and Borrelia spp. infection rates in Hokkaido)
Taylor Kyle, 高野 愛, 川端 寛樹, 下鶴 倫人, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 153回, 181, 181, Mar. 2012
(公社)日本獣医学会, English - Changes in blood glucose and insulin responses to intravenous glucose tolerance tests and blood biochemical values in adult female Japanese black bears (Ursus thibetanus japonicus)
Akari Kamine, Michito Shimozuru, Haruki Shibata, Toshio Tsubota, JAPANESE JOURNAL OF VETERINARY RESEARCH, 60, 1, 5, 13, Feb. 2012
English - 現在,国内で分離・同定できないウイルス性出血熱等の診断等の対応方法に関する研究 トガリネズミ目のハンタウイルスの診断系確立と国内の感染状況の把握
新井智, 浜田雅史, 多屋馨子, 岡部信彦, TAYLOR Kyle, 西澤次訓, 坪田敏男, 大館智志, 森川茂, 現在、国内で分離・同定できないウイルス性出血熱等の診断等の対応方法に関する研究 平成23年度 総括・分担研究報告書, 50, 55, 2012
Japanese - Ecological application of compound-specific stable nitrogen isotope analysis of amino acids : A case study of captive and wild bears(
Advances in molecular and stable isotope studies among the organic geochemical and related communities (Par
Nakashita Rumiko, Suzuki Yaeko, Akamatsu Fumikazu, Naito Yuichi I, Sato-Hashimoto Miho, Tsubota Toshio, Researches in organic geochemistry, 27, 0, 73, 79, 30 Sep. 2011
Several recent studies have suggested an innovative method for estimating the food sources, feeding habits, and trophic position of consumers in food webs, based on the compound-specific stable isotope analysis (CSIA) of amino acids. In this study, we used CSIA to study terrestrial mammals in a controlled feeding experiment with captive Asiatic black bears (Ursus thibetanus). The trophic position is estimated to be 1.7-1.9 for the bears, which is consistent with their actual trophic position (approximately 2). We also investigated the feeding habits of six wild Asiatic black bears (the same..., The Japanese Association of Organic Geochemists, English - クロミンククジラ胎子精巣のステロイドホルモン調節機構
佐々木基樹, 坪田敏男, 石川創, 茂越敏弘, 大隅清治, 手塚雅文, 宮本明夫, 福井豊, 北村延夫, 北海道獣医師会雑誌, 55, 8, 410, 410, 10 Aug. 2011
(公社)北海道獣医師会, Japanese - 北海道のエゾタヌキにおける疥癬の疫学調査について
佐鹿万里子, 阿部豪, 奥山みなみ, 坪田敏男, 北海道獣医師会雑誌, 55, 8, 409, 409, 10 Aug. 2011
(公社)北海道獣医師会, Japanese - 日本のげっ歯類のハンタウイルス感染状況に関する血清疫学調査とエゾヤチネズミが保有するHokkaidoウイルスの遺伝的多様性
尾崎由佳, 萩谷友洋, 真田崇弘, 瀬戸隆弘, TAYLOR Kyle, 吉川佳佑, IVANOV Leonid I, 好井健太朗, 坪田敏男, 池中良徳, 石塚真由美, 吉松組子, 有川二郎, 苅和宏明, 北海道獣医師会雑誌, 55, 8, 415, 415, Aug. 2011
(公社)北海道獣医師会, Japanese - 日本のげっ歯類のハンタウイルス感染状況に関する血清疫学調査とエゾヤチネズミが保有するHokkaidoウイルスの遺伝的多様性
尾崎由佳, 萩谷友洋, 真田崇弘, 瀬戸隆弘, TAYLOR Kyle, 吉川佳佑, IVANOV Leonid, 好井健太朗, 坪田敏男, 池中良徳, 石塚真由美, 吉松組子, 有川二郎, 苅和宏明, 日本獣医学会学術集会講演要旨集, 152回, 256, 256, Aug. 2011
(公社)日本獣医学会, Japanese - クマの大量出没の原因を明らかにして,人身被害を防ぐ
大井徹, 中下留美子, 岡輝樹, 大西尚樹, 高橋裕史, 正木隆, 阿部真, 宮本麻子, 佐野真琴, 坪田敏男, 山崎晃司, 森林総合研究所研究成果選集, 2011, 22, 23, Jul. 2011
Japanese - 道東・標津町における携帯電話を活用したリアルタイム通信によるヒグマ行動追跡
坪田敏男, 平野沙衣子, 藤本靖, 上野洋一, 長田雅裕, 郡山尚紀, 下鶴倫人, 日本生態学会大会講演要旨集, 58th, 211, 08 Mar. 2011
Japanese - ツキノワグマからのCytauxzoon原虫の検出と分離
陳内 理生, 前橋 克彦, 平田 晴之, 岩崎 いづみ, 中嶋 瑠衣, 藤澤 幸平, 寺田 裕, 下鶴 倫人, 坪田 敏男, 石原 智明, 獣医寄生虫学会誌, 9, 2, 168, 168, Mar. 2011
日本獣医寄生虫学会, Japanese - Estimating the success rate of ovulation and early litter loss rate in the Japanese black bear (Ursus thibetanus japonicus) by examining the ovaries and uteri
Atsushi Yamanaka, Kiyoshi Yamauchi, Tsunenori Tsujimoto, Toshio Mizoguchi, Toru Oi, Seigo Sawada, Michito Shimozuru, Toshio Tsubota, JAPANESE JOURNAL OF VETERINARY RESEARCH, 59, 1, 31, 39, Feb. 2011
English - Multi-locus sequence typing of Borrelia garinii isolated from humans, ticks, and rodents; Rodents were implicated as the main reservoir host of human pathogenic B.garinii in Japan.
Kawabata Hiroki, Oikawa Yozaburo, Kawamori Fumihiko, Kumagai Kunihiko, Mikami Toshiyuki, Hanaoka Nozomu, Ando Shuji, Honda Naoko, Taylor Kyle, Tsubota Toshio, Konnai Satoru, Takano Ai, Watanabe Haruo, Ohnishi Makoto, Nakao Minoru, Masuzawa Toshiyuki, Takada Nobuhiro, Yano Yasuhiro, Ishiguro Fubito, Fujita Hiromi, Itoh Takuya, JSMEZ Annual Meetings Abstracts, 63, 0, 69, 69, 2011
Multi-locus sequence typing of <I>Borrelia garinii</I> isolates from humans in Japan, and comparison with environmental isolates was performed. All isolates could be divided into two groups, and an association was detected between clinical and rodent isolates, suggesting that Japanese clinical isolates of <I>B.garinii</I> come from rodents via ticks., 日本衛生動物学会, Japanese - ワンヘルス理念に基づく動物由来感染症制御に関する研究 国内生態系におけるライム病ボレリアの維持伝播経路に関する研究
川端寛樹, 石ぐろ史, 藤田博己, 高田伸弘, 矢野泰弘, 増澤俊幸, 中尾稔, 伊東拓也, 及川陽三郎, TAYLOR Kyle, 坪田敏男, 今内覚, 川森文彦, 三上稔之, 熊谷邦彦, 高野愛, 安藤秀二, 花岡希, 本田尚子, 渡邉治雄, 大西真, ワンヘルス理念に基づく動物由来感染症制御に関する研究 平成22年度 総括・分担研究報告書, 17, 20, 2011
Japanese - エゾヒグマ(Ursus arctos yesoensis)におけるHepatozoon sp.寄生について
久保 正仁, 千葉 依里, 飯渕 るり子, 坪田 敏男, 佐々木 基樹, 酒井 洋樹, 柳井 徳磨, 日本野生動物医学会誌, 15, 2, 111, 113, Sep. 2010
日本野生動物医学会, Japanese - ツキノワグマからのCytauxzoon原虫の検出と分離
陳内 理生, 前橋 克彦, 平田 晴之, 岩崎 いづみ, 中嶋 瑠衣, 藤澤 幸平, 寺田 裕, 下鶴 倫人, 坪田 敏男, 石原 智明, 日本獣医学会学術集会講演要旨集, 150回, 192, 192, Sep. 2010
(公社)日本獣医学会, Japanese - ヒグマ・トランクキットを用いた普及啓発活動(北海道) (This number 人里に出没するクマ対策の普及啓発および地域支援事業)
坪田 敏男, 植木 玲一, 坪田 あゆみ, Bears Japan, 11, 1, 10, 13, Jul. 2010
知床財団, Japanese - 【クマの保全医学の研究動向】ニホンツキノワグマにおける繁殖と母体栄養状態の関連性
中村 幸子, 岡野 司, 柴田 治樹, 山中 淳史, 小松 武志, 淺野 玄, 坪田 敏男, 鈴木 正嗣, 獣医畜産新報, 63, 5, 361, 365, May 2010
文永堂出版(株), Japanese - 【クマの保全医学の研究動向】ニホンツキノワグマにおける精子形成の季節変化の制御機序
飯渕 るり子, 加味根 あかり, 下鶴 倫人, 坪田 敏男, 獣医畜産新報, 63, 5, 371, 374, May 2010
文永堂出版(株), Japanese - 【クマの保全医学の研究動向】Hepatozoon ursi ツキノワグマにおける新種の住血原虫
久保 正仁, 宇仁 茂彦, 吾妻 健, 坪田 敏男, 酒井 洋樹, 柳井 徳磨, 獣医畜産新報, 63, 5, 379, 382, May 2010
文永堂出版(株), Japanese - ニホンツキノワグマにおける冬眠前の脂肪蓄積メカニズム (特集 クマの保全医学の研究動向)
加味根 あかり, 下鶴 倫人, 坪田 敏男, 獣医畜産新報, 63, 5, 367, 370, May 2010
文永堂出版, Japanese - リス科動物精巣の機能形態学的研究 ミケリス(Callosciurus prevostii)、バナナリス(Callosciurus notatus)、オレンジクサビオモモンガ(Hylopetes Lepidus)
段 麻優子, 佐々木 基樹, Budipitojo Teguh, 遠藤 秀紀, 木村 順平, 押田 龍夫, 坪田 敏男, 北村 延夫, 日本獣医学会学術集会講演要旨集, 149回, 214, 214, Mar. 2010
(公社)日本獣医学会, Japanese - Changes in plasma gonadotropins, inhibin and testosterone concentrations and testicular gonadotropin receptor mRNA expression during testicular active, regressive and recrudescent phase in the captive Japanese black bear (Ursus thibetanus japonicus)
Ruriko Iibuchi, Akari Kamine, Michito Shimozuru, Junko Nio-Kobayashi, Gen Watanabe, Kazuyoshi Taya, Toshio Tsubota, JAPANESE JOURNAL OF VETERINARY RESEARCH, 57, 4, 185, 196, Feb. 2010
English - Immunohistochemical Localization of Steroidogenic Enzymes in the Testis of the Sika Deer (Cervus nippon) During Developmental and Seasonal Changes
Daisuke Hayakawa, Motoki Sasaki, Masatsugu Suzuki, Toshio Tsubota, Hiromasa Igota, Koichi Kaji, Nobuo Kitamura, JOURNAL OF REPRODUCTION AND DEVELOPMENT, 56, 1, 117, 123, Feb. 2010
English - 動物由来感染症の生態学的アプローチによるリスク評価等に関する研究 国内野生動物におけるFrancisella tularensis(野兎病菌)の保有状況
棚林清, 堀田明豊, 山本美江, 藤田修, 宇田晶彦, 進藤順治, 朴天鎬, 小山田敏文, 畑井仁, 工藤上, 坪田敏男, 苅和宏明, 青木美樹子, 溝口俊夫, 中下留美子, 中村幸子, 片山敦司, 動物由来感染症の生態学的アプローチによるリスク評価等に関する研究 平成21年度 総括・分担研究報告書, 2010 - Assessing sexual maturity of feral male raccoons (Procyon lotor) in Hokkaido
OKUYAMA Minami, FUKUI Daisuke, NAKAMURA Ryohei, TAKAHASHI Nobuhiro, SHIMOZURU Michito, TSUBOTA Toshio, The Journal of Reproduction and Development Supplement, 103, 43, 43, 2010
【目的】アライグマ(Procyon lotor)は、北海道において外来種として個体数を増やし分布域を広げてきている。その一因として高い繁殖力をもつ可能性が考えられるが、アライグマにおける繁殖生理には未だ解明されていない点が多い。特に、様々な種において個体の分散は若齢雄から始まるとされており、分布域拡大の要因を探る際に雄の性成熟時期の特定は不可欠といえる。そのため本研究では、北海道の雄アライグマがいつ性成熟を迎えるのかを明らかにすることを目的とした。【方法】2008年5月～2010年4月に北海道内で捕獲殺処分された234頭の野生雄アライグマを用いた。歯根の年齢線により区分された0、1、2および3歳以上の4グループにおいて、各月ごとに外見的特徴(精巣サイズ、陰茎露出の可否)、精巣組織所見(精細管径、精細胞発達ステージ、精巣上体管腔内精子存在率)を調べた。また、飼育下の0歳齢個体1例について、2008年12月～2010年3月までの毎月、精巣組織所見を調べた。【結果】野生の雄アライグマでは3～5月の出産期に生まれた後、体重増加と共に精巣重量が増加した。1歳の5月までは精細管内には精原細胞のみが認められた。その後、精巣重量は急増し、精細管径も大きく増大した。精原細胞は減数分裂を始め、10月には精子形成が認められた。また、ほとんどの個体で１歳の5～10月の間に陰茎が包皮から露出可能な状態になっていた。以上より、北海道では多くの個体で１歳の5月から春機発動が始まり、1歳の冬の交尾期には精子形成が完成すると考えられる。一方、個体によっては1歳に至る前に精子形成が観察されたものが数例存在した。これらの個体は農家の納屋などで捕獲されており、他の0歳齢個体と比べ体格が大きかったことからも、十分に餌資源を確保できる環境で生息していた可能性が高い。また、飼育下の0歳齢個体は生後1年足らずで精子形成が確認された。以上より、十分な餌資源のもとではより早期の精子形成が可能になる例があることも明らかになった。, THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT, Japanese - Growth variation in skull morphology of Kuril harbor seals (Phoca vitulina stejnegeri) and spotted seals (Phoca largha) in Hokkaido, Japan
Emiko Nakagawa, Mari Kobayashi, Masatsugu Suzuki, Toshio Tsubota, JAPANESE JOURNAL OF VETERINARY RESEARCH, 57, 3, 147, 162, Nov. 2009
English - 出没をめぐるツキノワグマの生理(<特集>クマ出没の生物学)
山中 淳史, 坪田 敏男, 森林科学 : 日本林学会会報, 0, 57, 9, 12, 01 Oct. 2009
一般社団法人日本森林学会, Japanese - エゾシカにおけるPAGを用いた早期妊娠診断方法の検討
柳川 洋二郎, 宮澤 千鶴, 松浦 友紀子, 下鶴 倫人, Noelita Melo de Sousa, Beckers Jean-Francis, 片桐 成二, 坪田 敏男, 北海道獣医師会雑誌, 53, 8, 109, 109, Aug. 2009
(公社)北海道獣医師会, Japanese - キタキツネ(Vulpes vulpes schrencki)精巣の構造および機能に関する免疫組織化学的研究
横山 知里, 佐々木 基樹, 坪田 敏男, 北村 延夫, 北海道獣医師会雑誌, 53, 8, 109, 109, Aug. 2009
(公社)北海道獣医師会, Japanese - Change in body weight of mothers and neonates and in milk composition during denning period in captive Japanese black bears (Ursus thibetanus japonicus)
Ruriko Iibuchi, Noriko Nakano, Tadashi Nakamura, Tadasu Urashima, Michito Shimozuru, Tetsuma Murase, Toshio Tsubota, JAPANESE JOURNAL OF VETERINARY RESEARCH, 57, 1, 13, 22, May 2009
English - 1998年以降の道内獣医大学における野生動物医学教育の動向
浅川 満彦, 佐々木 基樹, 坪田 敏男, 北海道獣医師会雑誌, 53, 4, 179, 184, Apr. 2009
北海道獣医師会, Japanese - 若手研究者によるクマの保全医学研究 雌の繁殖成功に関わる脂肪蓄積のメカニズムとその役割 ニホンツキノワグマにおける繁殖と母体栄養状態の関連性
中村 幸子, 岡野 司, 柴田 治樹, 山中 淳史, 小松 武志, 淺野 玄, 坪田 敏男, 鈴木 正嗣, 日本獣医学会学術集会講演要旨集, 147回, 193, 193, Mar. 2009
(公社)日本獣医学会, Japanese - 若手研究者によるクマの保全医学研究 雌の繁殖成功に関わる脂肪蓄積のメカニズムとその役割 ニホンツキノワグマにおける冬眠前の脂肪蓄積に関する代謝メカニズムの解明
加味根 あかり, 中村 幸子, 飯渕 るり子, 山中 淳史, 柴田 治樹, 下鶴 倫人, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 147回, 193, 193, Mar. 2009
(公社)日本獣医学会, Japanese - 若手研究者によるクマの保全医学研究 雄の季節繁殖性のメカニズムと人工繁殖 ツキノワグマにおける精子形成の季節変化とその制御機構
飯渕 るり子, 岩永 敏彦, 下鶴 倫人, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 147回, 194, 194, Mar. 2009
(公社)日本獣医学会, Japanese - 若手研究者によるクマの保全医学研究 クマに伝播する寄生虫感染症 野生ニホンツキノワグマ(Ursus thibetanus japonicus)におけるクマフィラリア(Dirofilaria ursi)及びクマ回虫(Baylisascaris transfuga)の病理学的及び分子生物学的検索
辻 一, 柳井 徳磨, 坪田 敏男, 吾妻 健, 宇仁 茂彦, 酒井 洋樹, 柵木 利昭, 日本獣医学会学術集会講演要旨集, 147回, 195, 195, Mar. 2009
(公社)日本獣医学会, Japanese - 若手研究者によるクマの保全医学研究 クマに伝播する寄生虫感染症 Hepatozoon ursi:ツキノワグマにおける新種の住血原虫
久保 正仁, 宇仁 茂彦, 吾妻 健, 坪田 敏男, 佐々木 基樹, 酒井 洋樹, 柵木 利昭, 柳井 徳磨, 日本獣医学会学術集会講演要旨集, 147回, 195, 195, Mar. 2009
(公社)日本獣医学会, Japanese - 地域支援事業作業部会報告 (This number 経過報告 人里に出没するクマ対策の普及啓発および地域支援事業)
坪田 敏男, Bears Japan, 9, 3, 64, 67, Feb. 2009
知床財団, Japanese - Quantitative and qualitative analyses of fecal gonadal steroid metabolites for monitoring of reproductive endocrine in Tsushima leopard cat (Prionailurus bengalensis euptilurus).
ADACHI Itsuki, KUSUDA Satoshi, NAGAO Eiji, TAIRA Yumiko, ASANO Makoto, TSUBOTA Toshio, DOI Osamu, The Journal of Reproduction and Development Supplement, 102, 1023, 1023, 2009
【目的】ツシマヤマネコは国内で最も絶滅のおそれの高い哺乳類の一種であり、現在4施設で飼育下繁殖の取り組みが行われている。そこで本種の繁殖生理の解明を目的として、糞中の性ステロイドホルモン代謝物の測定による非侵襲的な内分泌動態のモニタリングを行った。さらにその測定法の有効性を検討するため、糞中の性ステロイドホルモン代謝物の定性分析を行った。【方法】福岡市動物園で飼育されていた雌のツシマヤマネコ1頭を対象として、2004～2006年の交尾期および妊娠期を含む時期に糞を採取した。糞は凍結乾燥後に80％メタノールで性ステロイドホルモン代謝物を抽出し、エストラジオール-17β（E2）およびプロジェステロン（P4）抗体を用いた酵素免疫測定法によりそれぞれの代謝物を定量した。また、代謝物を明らかにするため、E2含量の高い期間および妊娠期間中の糞をメタノール抽出してSep-Pak C18カートリッジを用いて精製し、E2およびP4代謝物の分離を逆相HPLCにより行った。回収したフラクション中のE2およびP4代謝物の免疫反応性のピークを、E2代謝物2種およびP4代謝物6種の標準物質の溶出時間と比較した。【結果】糞中E2代謝物含量は、交尾前に明確な上昇を示し、糞中P4代謝物含量は、交尾日以降顕著な上昇を示した。糞中E2代謝物の定性分析の結果、E2およびエストロン（E1）の溶出位置と一致する明確なピークが認められた。妊娠期の糞中にはP4はわずかで、5α-pregnane-3α-ol-20-one、5α-pregnane-3β-ol-20-oneおよび5α-pregnane-3α、20-dioneの溶出位置と一致する明確なピークが認められた。以上の結果から、ツシマヤマネコの糞を用いた卵胞活動のモニタリングにはE2またはE1の測定が、また排卵や妊娠のモニタリングには5α系プレグナンに高い交叉性をもつ抗体を用いた測定が有効であることが示された。, THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT, Japanese - Annual Changes in Serum Leptin Concentration in the Adult Female Japanese Black Bear (Ursus thibetanus japonicus)
Toshio Tsubota, Miho Sato, Tsukasa Okano, Sachiko Nakamura, Makoto Asano, Takeshi Komatsu, Haruki Shibata, Masayuki Saito, JOURNAL OF VETERINARY MEDICAL SCIENCE, 70, 12, 1399, 1403, Dec. 2008
English - Immunohistochemical localization of the estrogen receptor alpha (ER alpha) and progesterone receptor (PR) in the uterus of sika deer (Cervus nippon) during pregnancy
Yojiro Yanagawa, Yukiko Matsuura, Masatsugu Suzuki, Seiji Katagiri, Toshio Tsubota, JAPANESE JOURNAL OF VETERINARY RESEARCH, 56, 3, 139, 149, Nov. 2008
English - Hepatozoon ursi n. spa (Apicomplexa : Hepatozoidae) in Japanese black bear (Ursus thibetanus japonicus)
Masahito Kubo, Shigehiko Uni, Takeshi Agatsuma, Mitsuru Nagataki, Roger J. Panciera, Toshio Tsubota, Sachiko Nakamura, Hiroki Sakai, Toshiaki Masegi, Tokuma Yanai, PARASITOLOGY INTERNATIONAL, 57, 3, 287, 294, Sep. 2008
English - Use of Bioelectrical Impedance Analysis to Measure the Fat Mass of the Japanese Black Bear(Ursus thibetanus japonicus)
NAKAMURA Sachiko, OKANO Tsukasa, YOSHIDA Yutaka, MATSUMOTO Ayumi, MURASE Yutaka, KATO Haruki, KOMATSU Takeshi, ASANO Makoto, SUZUKI Masatsugu, SUGIYAMA Makoto, TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 13, 1, 15, 20, Mar. 2008
Body fat mass(FM) of the Japanese black bear (Ursus thibetanus japonicus) was examined by bioelectrical impedance analysis(BIA) using Model Quantum X (RJL systems). Whole-body resistance was measured between forelimbs and hind limbs in the recumbent position. The FM was calculated by the equations for the American black bear. In 5 captive Japanese black bears, from September 2005 to January 2006, changes in FM and body mass(BM) were highly correlated (r=0.89). This study demonstrates that BIA is useful in the measurement of FM in the Japanese black bear, and that an increase in BM in autumn..., Japanese Society of Zoo and Wildlife Medicine, English - The prevalence of antibiotic-resistance Escherichia coli isolated from Japanese macaques (Macaca fuscata) in Shimokita Peninsula
OGAWA Keiko, YAMAGUCHI Keiji, SUZUKI Masatsugu, TSUBOTA Toshio, FUKUSHI Hideto, Primate Research Supplement, 24, 63, 63, 2008
海外では、野生動物や生態系内の薬剤耐性菌が人や家畜への感染源になるのではないかという懸念から、あるいは水の糞便汚染の汚染源特定のための指標の一つとして、野生動物の薬剤耐性菌についての研究が近年行われている。国内でも、野生動物と人や人の居住地域との接触の程度を示す指標として、野生動物の耐性菌保有状況調査が行われるようになっているものの、いまだ十分な情報は得られていないのが現状である。そこで本研究では、遊動域などの生態学的データが蓄積されている青森県下北半島に生息するニホンザル（Macaca fuscata）を対象とし、薬剤耐性大腸菌の保有状況を調査した。2005年と2006年にニホンザルの糞便285検体（野生265検体、飼育20検体）を採取し、大腸菌の分離同定をした。一部の菌株に対しCLSI（Clinical and Laboratory Standards Institute）に従い、24種類の抗菌薬と抗生物質について1濃度ディスク法による薬剤感受性試験を実施した。糞便285検体中176検体から290株の大腸菌株を分離した。感受性試験を実施した糞便71検体（野生62検体、飼育9検体）における薬剤耐性大腸菌保有率は、それぞれ野生個体で79.0%（49/62）、飼育個体で44.4%（4/9）だった。セファロチンの単剤耐性株が17株、アンピシリンの単剤耐性株が13株、両剤耐性株が27株、ストレプトマイシンの単剤耐性株が1株分離された。今回試験を実施した全ての薬剤に対して感受性の菌株は25株だった。野生のサルの耐性菌保有率は、これまで報告されている他地域の野鳥などの保有率（0-40.0%）に比べて高かった。これは、過去の報告では人口密度の低い地域の希少種を中心に調査しているのに対し、本研究では農地や道路沿いなど人の居住地域を頻繁に利用するサルの群れを中心に調査したためだと考えられた。, Primate Society of Japan - Seasonal Change of Expression of Steroidogenic Enzymes mRNA in Japanese Black Bear ( Ursus thibetanus japonicus ) Testis
Iibuchi Ruriko, Iwanaga Toshihiko, Shimozuru Michito, Tsubota Toshio, The Journal of Reproduction and Development Supplement, 101, 203, 203, 2008
【目的】ニホンツキノワグマは長日季節繁殖動物であり、精子形成は顕著な季節性を示す。交尾期である初夏には精巣内で活発な精子形成が行われるが、秋から冬にかけて精細胞の分化が停止する。精細胞の分化が再開するのは冬眠後期にあたる2～3月頃である。この精子形成の季節変化に同調して、精巣における性ステロイド産生も季節変動することが知られている。しかし、このような性ステロイド産生および精子形成の季節変化を調節している機構は明らかではない。本研究では、ツキノワグマの精巣におけるステロイド代謝酵素mRNA発現の季節変化について検討した。【方法】交尾期（6月）および非交尾期（11月、1月、2月、3月）に成熟雄ツキノワグマ３頭より採血およびバイオプシーによる精巣組織の採取を行った。精巣組織の凍結切片を作製し、in situ hybridization法により性ステロイドの代謝・合成に関わる5種類の酵素（P450scc, 3βHSD, P450c17, 17βHSD3およびP450arom）のmRNAを検出した。【結果・考察】交尾期の精巣では精子の形成が行われていた。11および1月の精巣では精細胞の分化は見られなかったが、2～3月には分化の再開が確認された。P450scc, 3βHSDおよびP450c17 mRNAは、交尾期の精巣の間質組織に発現が認められた。3βHSDは、非交尾期である11～2月に発現が低下し、精子形成の再開が観察された3月頃に発現が再び上昇した。一方、P450sccおよびP450c17 mRNAは交尾期および非交尾期の全ての月で発現が認められ、季節変化は観察されなかった。17βHSD3 mRNAは精細管内の基底側に発現が見られ、季節変化は認められなかった。以上の結果より、ツキノワグマ精巣におけるアンドロジェン合成の鍵となる酵素は3βHSDであり、その発現の季節変化がアンドロジェン合成の季節変化に関与している可能性が示唆された。また、P450arom mRNAは主に交尾期の精細胞で発現が認められた。, THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT, Japanese - ニホンツキノワグマにおけるレプチンレセプター(Ob-R)の発現部位とその季節変化
中村 幸子, 淺野 玄, 杉山 誠, 鈴木 正嗣, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 144回, 170, 170, Aug. 2007
(公社)日本獣医学会, Japanese - 回虫科におけるクマ回虫(Baylisascaris transfuga)の分子生物学的位置付けおよび病原性の検討
辻 一, 柳井 徳磨, 柵木 利昭, 酒井 洋樹, 坪田 敏男, 宇仁 茂彦, 吾妻 健, 日本獣医学会学術集会講演要旨集, 143回, 158, 158, Mar. 2007
(公社)日本獣医学会, Japanese - 食肉における家畜・家禽のウイルス疾病に関する研究 食肉に供される動物におけるA群ロタウイルスの感染状況調査
杉山誠, 安部昌子, 川口まり子, 長谷部文子, 伊藤直人, 宮澤清志, 村瀬哲磨, 坪田敏男, 石黒直隆, 淺野玄, 伊藤雅, 山下照夫, 榮賢司, 食肉における家畜・家禽のウイルス疾病に関する研究 平成18年度 総括・分担研究報告書, 49, 58, 2007
Japanese - クロミンククジラ(Balaenoptera bonaerensis)における胎盤および非妊娠子宮の形態学的および免疫組織化学的研究
天野 容子, 佐々木 基樹, 石川 創, 茂越 敏弘, 大隅 清治, 手塚 雅文, 宮本 明夫, 福井 豊, 坪田 敏男, 北村 延夫, 日本獣医学会学術集会講演要旨集, 142回, 34, 34, Aug. 2006
(公社)日本獣医学会, Japanese - 牛精巣のステロイド産生機能は精巣温度上昇に伴い変化する(Steroidogenic functions of the bovine testis alters with increased testicular temperature)
Devkota Bhuminand, 佐々木 基樹, 松井 基純, 坪田 敏男, 金子 悦史, 宮本 明夫, Montoya Carlos Amaya, 大澤 健司, 橋爪 力, 三宅 陽一, 日本獣医学会学術集会講演要旨集, 142回, 129, 129, Aug. 2006
(公社)日本獣医学会, English - ニホンツキノワグマ(Ursus thibetanus japonicus)における排卵様式の解明およびゴナドトロピン製剤による排卵の誘起
岡野司, 中村幸子, 中下留美子, 小松武志, 村瀬哲磨, 村瀬哲磨, 淺野玄, 淺野玄, 坪田敏男, 坪田敏男, 日本野生動物医学会大会・講演要旨集, 12th, 2006 - 国内の野生動物における日本脳炎ウイルスに対する血清疫学調査−イノシシが日本脳炎ウイルスの増殖動物である可能性−.
杉山 誠, 高木愛香, 源 宣之, 伊藤直人, 淺野 玄, 坪田敏男, 石黒直隆, 伊藤 雅, 山下照夫, 榮 賢司, 日本獣医畜産新報 JVM, 59, 4, 284, 285, 2006
文永堂出版(株), Japanese - Immunolocalization of steroidogenic enzymes in the fetal, neonatal and adult testis of the Shiba goat
Q Weng, MS Medan, LQ Ren, G Watanabe, T Tsubota, K Taya, EXPERIMENTAL ANIMALS, 54, 5, 451, 454, Oct. 2005
English - 4 チンパンジーの繁殖特性に地域個体群変異をもたらす要因の検討(X.共同利用研究 2.研究成果)
藤田 志歩, 坪田 敏男, 霊長類研究所年報, 35, 35, 103, 103, 31 Aug. 2005
京都大学霊長類研究所, Japanese - Immunolocalization of steroidogenic enzymes P450scc, 3 beta HSD, P450c17, and P450arom in Gottingen miniature pig testes
Q Weng, MS Medan, G Watanabe, T Tsubota, Y Tanioka, K Taya, JOURNAL OF REPRODUCTION AND DEVELOPMENT, 51, 3, 299, 304, Jun. 2005
English - Male pseudohermaphroditism in a raccoon dog (Nyctereutes procynoides)
Q Weng, T Murase, M Asano, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 67, 6, 603, 605, Jun. 2005
English - Immunolocalization of steroidogenic enzymes P450scc, 3 beta HSD, P450c17, and P450arom in Gottingen miniature pig testes
Q Weng, MS Medan, G Watanabe, T Tsubota, Y Tanioka, K Taya, JOURNAL OF REPRODUCTION AND DEVELOPMENT, 51, 3, 299, 304, Jun. 2005
English - Immunolocalization of steroidogenic enzymes in the corpus luteum and placenta of the Japanese Shiba goat
Q Weng, MS Medan, LQ Ren, G Watanabe, T Tsubota, K Taya, JOURNAL OF REPRODUCTION AND DEVELOPMENT, 51, 2, 247, 252, Apr. 2005
English - Adaptation of the hindlimbs for climbing in bears
M Sasaki, H Endo, O Wiig, AE Derocher, T Tsubota, H Taru, M Yamamoto, K Arishima, Y Hayashi, N Kitamura, J Yamada, ANNALS OF ANATOMY-ANATOMISCHER ANZEIGER, 187, 2, 153, 160, Apr. 2005
English - 国内の野生動物における日本脳炎ウイルスに対する血清疫学調査
高木 愛香, 杉山 誠, 伊藤 直人, 淺野 玄, 坪田 敏男, 源 宣之, 日本獣医学会学術集会講演要旨集, 139回, 185, 185, Mar. 2005
(公社)日本獣医学会, Japanese - ジャイアントパンダの自然史と保全生物学
Durrant Barbara, 赤木 智香子, 坪田 敏男, Journal of Reproduction and Development, 51, 1, 巻頭10, 12, Feb. 2005
Japanese Society of Animal Reproduction, Japanese - Rapid, Easy and Reliable Sexing Method for Falconiformes by PCR
ITO Hideyuki, ENDO Chihiro, YAMAJI Akiko, ABE Motoko, MURASE Tetsuma, ASANO Makoto, TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 10: 79-84, 2, 79, 84, 2005
Many species of Falconiformes are difficult to sex, since they are monomorphic in external morphology, as are many other avian species. This problem may prevent ecological studies of them and make it difficult to plan conservation programs. Therefore, development of a sexing method for Falconidae has been desirable. We performed sex identification for eight species of raptors that inhabit Japan, using a method based on the difference of intronic length between the CHD1W and CHD1Z genes. This method of sexing is easier and quicker to perform than other methods developed thus far, and made identification possible for all species tested. Moreover, successful sexing from a small DNA source suggests that this method may be applicable to the research of individuals/populations in the wild. In conclusion, the method used in this study is very useful for sex identification in raptors and could be of great value for any future conservation of rare raptors., Japanese Society of Zoo and Wildlife Medicine, English - ニホンツキノワグマ(Ursus thibetanus japonicus)における電気刺激射精法による精液採取-低刺激電圧およびぼうこう洗浄の尿混入抑制効果-
岡野司, 中村幸子, 水上(中下)留美子, 小松武志, 村瀬哲磨, 村瀬哲磨, 浅野玄, 浅野玄, 坪田敏男, 坪田敏男, 日本野生動物医学会大会・講演要旨集, 11th, 2005 - 浮桟橋へのサンゴ移植の研究
久高 將佑, 天 石文, 高山 百合子, 岩田 芳隆, 信田 浩司, 小倉 礁, 三富 聡, 大友 祥太, 渡辺 義公, 市村 靖光, 鈴木 健, 平安山 武雄, 大野 文良, 長谷 一矢, 多喜川 昇, 小林 仁, 岩崎 秀治, 篠原 伸和, 長 雄一, 高田 雅之, 大橋 和彦, 岡崎 克則, 阿出川 隆之, 金子 正美, 遠藤 大二, 浅川 満彦, 坪田 敏男, 淺野 玄, 赤松 里香, Buheaosier, Asai Miki, Kaneko Masami, Ohtaishi Noriyuki, 木原 一禎, 小野寺 収, 濱田 靖弘, 後藤 隆一郎, 窪田 英樹, 中村 真人, 桑原 浩平, 長田 勉, 三浦 二郎, 松島 健将, 中島 義晴, 太田 幸雄, 竹森 憲章, 樺澤 雅之, 渡辺 克実, 大山 成人, 久保 田学, 安保 芳久, 大束 淳一, 山形 定, 山崎 高, 北野 智也, 帆秋 利洋, 地球環境シンポジウム講演論文集, 13, 13, 341, 366, 2005
公益社団法人 土木学会, Japanese - A Preliminary Examination of Data-base System Collecting, Stocking, Processing and Publishing Information about Potential Pathogens for Causing Outbreak of Wild Birds.
Osa Yuichi, Akamatsu Rika, Takada Masayuki, Ohashi Kazuhiko, Okazaki Katsunori, Kaneko Masami, Endoh Daiji, Asakawa Mitsuhiko, Tsubota Toshio, Asano Makoto, Abstracts of the Annual Meeting of the Ecological Society of Japan, 52, 0, 432, 432, 2005
生態学会２００４年大会において「野生鳥類の大量死リスク評価につながる病原体データベースの基本コンセプトについて」を発表し、病原体情報の収集分析のために、広域サンプリング_-_＞病原体タイプの同定_-_＞情報管理・蓄積_-_＞情報解析_-_＞情報公開及び活用といった基本的なコンセプト（設計図）を提示した。
本発表においては、これらのコンセプトに基づいたシステムの実際的な運用例等を示すとともに、２００３年度に実施したサンプリングにより把握できた野生鳥類における病原体保有動態について中間的な報告を行う。また、実際に罹病あるいは死亡した個体に関する病原体（死因）情報のフォーマットや、「情報の共通化・共有化」等の具体的な運用面の問題についても述べる。さらに野生鳥類の移動_-_分散様式・病原体の伝播_-_発病様式・湖沼等の生息環境の空間構造・人間活動との相互作用を視野においた野生鳥類大量死発生予測モデリングについて手法検討を行う。, ECOLOGICAL SOCIETY OF JAPAN, Japanese - Chemical characterization of sialyl oligosaccharides in milk of the Japanese black bear, Ursus thibetanus japonicus
T Urashima, T Nakamura, K Teramoto, Arai, I, T Saito, T Komatsu, T Tsubota, COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY, 139, 4, 587, 595, Dec. 2004
English - Ceramide enhances acrosomal exocytosis triggered by calcium and the calcium ionophore A23187 in boar spermatozoa
T Murase, N Imaeda, N Kondoh, T Tsubota, JOURNAL OF REPRODUCTION AND DEVELOPMENT, 50, 6, 667, 674, Dec. 2004
English - Immunohistochemical localization of steroidogenic enzymes in the testis of Hokkaido Sika Deer (Cerpus nippon yesoensis)
D Hayakawa, M Sasaki, C Akabane, N Kitamura, T Tsubota, M Suzuki, J Yamada, JOURNAL OF VETERINARY MEDICAL SCIENCE, 66, 11, 1463, 1466, Nov. 2004
English - Electroejaculation and semen cryopreservation of free-ranging Japanese black bears (Ursus thibetanus japonicus)
T Okano, T Murase, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 66, 11, 1371, 1376, Nov. 2004
English - Effects of final dilution rate, sperm concentration and times for cooling and glycerol equilibration on post-thaw characteristics of canine spermatozoa
T Okano, T Murase, M Asano, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 66, 11, 1359, 1364, Nov. 2004
English - 施設5 チンパンジーの繁殖特性に地域個体群変異をもたらす要因の検討(X.共同利用研究 2.共同利用研究成果)
藤田 志歩, 坪田 敏男, 霊長類研究所年報, 34, 34, 151, 151, 30 Sep. 2004
京都大学霊長類研究所, Japanese - Immunolocalization of P450arom and its mRNA Expression in the Ovary of Wild Raccoon Dogs(Nyctereutes procynoides)
WENG Qiang, MURASE Tetsuma, ASANO Makoto, TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 9, 2, 65, 70, Sep. 2004
Five pairs of ovaries were obtained from wild adult raccoon dogs (Nyctereutes procynoides) in November 2001, March and April 2002, and February and March 2003. Two of the 5 ovaries (March and April) contained corpora lutea. The purpose of the present study was to investigate immunolocalization of P450arom and its mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR) in wild raccoon dog ovaries. Immunoreactive aromatase was detected in granulosa cells, internal theca cells and lutein cells. The P450arom mRNA was expressed in the ovaries of all wild raccoon dogs. We also..., Japanese Society of Zoo and Wildlife Medicine, English - 分化発達にともなうウシ精巣の細胞増殖能とステロイド合成酵素の局在
佐々木 基樹, 松崎 重範, 高橋 健一, 坪田 敏男, 北村 延夫, 山田 純三, 日本獣医学会学術集会講演要旨集, 138回, 41, 41, Aug. 2004
(公社)日本獣医学会, Japanese - ラテックス凝集試験を用いた数種の野生動物におけるA群ロタウイルスの血清疫学調査
安部 昌子, 杉山 誠, 山吉 誠也, 伊藤 直人, 源 宣之, 淺野 玄, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 138回, 130, 130, Aug. 2004
(公社)日本獣医学会, Japanese - Evidence that bears are induced ovulators
WR Boone, BB Keck, JC Catlin, KJ Casey, ET Boone, PS Dye, RJ Schuett, T Tsubota, JC Bahr, THERIOGENOLOGY, 61, 6, 1163, 1169, Apr. 2004
English - Utility of Cross-species Amplification among Raptors
ITO Hideyuki, SUDO YAMAJI Akiko, ABE Motoko, MURASE Tetsuma, TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 9, 1, 39, 43, Mar. 2004
Some species of raptors, such as the golden eagle (Aquila chrysaetos) and the mountain hawk-eagle (Spizaetus nipalensis), were recently reduced in population by habitat destruction. Conservation of habitats and genetic diversity for raptors is crucial. However, there is little genetic information on raptors. In this study, 8 microsatellite markers isolated from the peregrine falcon (Falco peregrinus) and gyrfalcon (Falco msticolus) were applied to 6 other raptors. The number of loci detected polymorphisms in the black kite, goshawk, kestrel, marsh harrier, golden eagle and mountain hawk-eag..., Japanese Society of Zoo and Wildlife Medicine, English - Immunohistochemical localization of steroidogenic enzymes in corpus luteum of wild sika deer during early mating season
Y Matsuura, M Suzuki, D Hayakawa, M Asano, M Sasaki, N Kitamura, J Yamada, T Tsubota, N Ohtaishi, JAPANESE JOURNAL OF VETERINARY RESEARCH, 51, 3-4, 167, 172, Feb. 2004
English - Immunohistochemical localization of steroidogenic enzymes in corpus luteum of wild sika deer during early mating season
Y Matsuura, M Suzuki, D Hayakawa, M Asano, M Sasaki, N Kitamura, J Yamada, T Tsubota, N Ohtaishi, JAPANESE JOURNAL OF VETERINARY RESEARCH, 51, 3-4, 167, 172, Feb. 2004
English - Utility of Cross-species Amplification among Raptors
Hideyuki ITO, Akiko SUDO YAMAJI, Motoko ABE, Tetsuma MURASE, Toshio TSUBOTA, Japanese Journal of Zoo and Wildlife Medicine, 9: 39-43, 1, 39, 43, 2004
Japanese Society of Zoo and Wildlife Medicine - TR-FIA法によるニホンツキノワグマ糞中性ステロイドホルモン濃度測定法の確立およびその季節変動
中村幸子, 岡野司, 八代田千鶴, 水上(中下)留美子, 小松武志, 村瀬哲磨, 村瀬哲磨, 浅野玄, 浅野玄, 坪田敏男, 坪田敏男, 日本野生動物医学会大会・講演要旨集, 10th, 2004 - 飼育下成熟雌 ニホンツキノワグマ(Ursus thibetanus japonicus)における血清中プロジェステロン濃度の変化-ツキノワグマは交尾排卵動物か?-
岡野司, 八代田千鶴, 水上(中下)留美子, 小松武志, 村瀬哲磨, 村瀬哲磨, 坪田敏男, 坪田敏男, 日本野生動物医学会大会・講演要旨集, 10th, 2004 - The prevalence of bovine herpevirus-1 in traditional cattle in Southern Province, Zambia
AS Mweene, H Fukushi, GS Pandey, M Syakalima, M Simuunza, M Malamo, A Nambota, KL Samui, T Tsubota, Y Nakazato, M Onuma, J Yasuda, REVUE SCIENTIFIQUE ET TECHNIQUE DE L OFFICE INTERNATIONAL DES EPIZOOTIES, 22, 3, 873, 877, Dec. 2003
English - Spermatogenesis, serum testosterone levels and immunolocalization of steroidogenic enzymes in the wild male Japanese black bear (Ursus thibetanus japonicus)
T Okano, T Murase, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 65, 10, 1093, 1099, Oct. 2003
English - Seasonal changes in spermatogenesis and testicular steroidogenesis in wild male raccoon dogs (Nyctereutes procynoides)
W Qiang, T Murase, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 65, 10, 1087, 1092, Oct. 2003
English - Levels and Accumulation Profiles of PCDD/Fs and Coplanar PCBs in Avian Species from Japan
HASEGAWA Jun, MATSUDA Muneaki, KAWANO Masahide, SUDO Akiko, TSUBOTA Toshio, HIRAOKA Takashi, WAKIMOTO Tadaaki, Journal of environmental chemistry, 13, 3, 765, 779, 24 Sep. 2003
Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar PCBs (Co-PCBs) in ten species of wild birds collected from Japan were analyzed. The results revealed that the concentrations and homologue / isomer profiles were speciesspecific, featuring with their unique habitats and feeding habits. The rank of residue levels of PCDD/Fs and Co-PCBs were following : granivore ≅ omnivore < carnivore ≅ piscivore < predator, and suggested that persistent and toxic isomers tend to bioaccumulate selectively increasing with a trophic level. PCDD/Fs predominantly contributed to TEQ in species whose food source mainly depended on the terrestrial ecosystem, while Co-PCBs in species on the aquatic ecosystem, implying the contamination pattern vary according to habitats. The result of cluster analysis using the profile data of PCDD/Fs isomer or TEQ contribution considerably corresponded to the classification by each ecological characteristic. TEQ levels in wild birds from Japan analyzed in this study were within the range of those from other countries. However, raptors at the top of terrestrial food chain showed the elevated level among species, thus the result emphasizes it is necessary to elucidate the exposure route in their ecosystem., Japan Society for Environmental Chemistry, Japanese - 盲導犬における人工繁殖の試み
白根 園絵, 村瀬 哲磨, 坪田 敏男, 古橋 博昭, 藤本 幸徳, 諏訪 義典, 日本獣医学会学術集会講演要旨集, 136回, 191, 191, Sep. 2003
(公社)日本獣医学会, Japanese - スイムアップ法による犬精巣上体精子の回収と凍結保存
茂崎 宇十沙, 村瀬 哲磨, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 136回, 191, 191, Sep. 2003
(公社)日本獣医学会, Japanese - Comparison of cation transport and regulatory volume decrease between red blood cells from the Japanese black bear and the dog
H. Fujise, T. Nakayama, N. Iwase, T. Tsubota, T. Komatsu, Comparative Clinical Pathology, 12, 1, 33, 39, May 2003
English - 緒言 (特集 野生動物モニタリングと環境保護--第134回日本獣医学会学術集会 シンポジウムより)
村田 浩一, 坪田 敏男, 獣医畜産新報, 56, 4, 281, 283, Apr. 2003
文永堂出版, Japanese - Sex identification by alternative polymerase chain reaction methods in Falconiformes
H Ito, A Sudo-Yamaji, M Abe, T Murase, T Tsubota, ZOOLOGICAL SCIENCE, 20, 3, 339, 344, Mar. 2003
English - Sex identification by alternative polymerase chain reaction methods in Falconiformes
Hideyuki Ito, Akiko Sudo-Yamaji, Motoko Abe, Tetsuma Murase, Toshio Tsubota, Zoological Science, 20, 3, 339, 344, 01 Mar. 2003
English - クマ類の繁殖に関する生理学的および内分泌学的研究
坪田 敏男, 日本獣医学会学術集会講演要旨集, 135回, 9, 9, Mar. 2003
(公社)日本獣医学会, Japanese - Sex identification by alternative polymerase chain reaction methods in Falconiformes
H Ito, A Sudo-Yamaji, M Abe, T Murase, T Tsubota, ZOOLOGICAL SCIENCE, 20, 3, 339, 344, Mar. 2003
English - Levels and Accumulation Profiles of PCDD/Fs and Coplanar PCBs in Avian Species from Japan
HASEGAWA Jun, MATSUDA Muneaki, KAWANO Masahide, SUDO Akiko, TSUBOTA Toshio, HIRAOKA Takashi, WAKIMOTO Tadaaki, JEC, 13, 3, 765, 779, 2003
Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar PCBs (Co-PCBs) in ten species of wild birds collected from Japan were analyzed. The results revealed that the concentrations and homologue / isomer profiles were speciesspecific, featuring with their unique habitats and feeding habits. The rank of residue levels of PCDD/Fs and Co-PCBs were following : granivore ≅ omnivore < carnivore ≅ piscivore < predator, and suggested that persistent and toxic isomers tend to bioaccumulate selectively increasing with a trophic level. PCDD/Fs predominantly contributed to TEQ in species whose food source mainly depended on the terrestrial ecosystem, while Co-PCBs in species on the aquatic ecosystem, implying the contamination pattern vary according to habitats. The result of cluster analysis using the profile data of PCDD/Fs isomer or TEQ contribution considerably corresponded to the classification by each ecological characteristic. TEQ levels in wild birds from Japan analyzed in this study were within the range of those from other countries. However, raptors at the top of terrestrial food chain showed the elevated level among species, thus the result emphasizes it is necessary to elucidate the exposure route in their ecosystem., Japan Society for Environmental Chemistry, Japanese - クマハギ激害地におけるニホンツキノワグマ (Ursus thibetanus japonicus) の食性
吉田 洋, 林 進, 坪田 敏男, 村瀬 哲磨, 岡本 卓也, 白濱 直樹, 岡野 司, 尾崎 智子, 日本生態学会大会講演要旨集, 50, 140, 140, 2003
日本生態学会, Japanese - Paternity Determination Using DNA Fingerprinting in Captive Japanese Black Bears (Ursus thibetanus japonicus)
YAMAMOTO Kaori, KAWAMURA Atsuki, TSUBOTA Toshio, TSURUGA Hifumi, KOMATSU Takeshi, MURASE Tetsuma, KITA Isao, KUDO Tadaaki, Japanese Journal of Zoo and Wildlife Medicine, 7, 2, 103, 108, Sep. 2002
We examined the availability of DNA fingerprinting in paternity determination of the captive Japanese black bear, Ursus thibetanus japonicus. The DNA fingerprint using the restriction enzyme Hinf I and (GATA)_4 probe was available for individual identification and paternity determination. Eleven females and their 13 cubs born from 1995 to 1997 along with 22 males were tested in the paternity determination. Seven male bears were determined as putative fathers of the 13 cubs. Two males in particular were the putative fathers of 8 cubs. Our study suggests that, under captive conditions, some m..., Japanese Society of Zoo and Wildlife Medicine, English - Sequence comparison of the dopamine receptor D4 exon iii repetitive region in several species of the order Carnivora
Miho Inoue-Murayama, Naoto Matsuura, Yuichi Murayama, Toshio Tsubota, Toshiroh Iwasaki, Hitoshi Kitagawa, Shin'ichi Ito, Journal of Veterinary Medical Science, 64, 8, 747, 749, Aug. 2002
English - Sequence comparison of the dopamine receptor D4 exon iii repetitive region in several species of the order Carnivora
Miho Inoue-Murayama, Naoto Matsuura, Yuichi Murayama, Toshio Tsubota, Toshiroh Iwasaki, Hitoshi Kitagawa, Shin'ichi Ito, Journal of Veterinary Medical Science, 64, 8, 747, 749, Aug. 2002
English - 「野生動物の研究と管理技術」, 日本野生動物医学会・野生生物学会監修, 鈴木正嗣 編訳, 2001年11月, 文永堂出版株式会社 刊, A4判, 898ページ, 定価20,000円+税
坪田 敏男, The journal of veterinary medical science, 64, 6, s・1, 25 Jun. 2002
社団法人日本獣医学会, Japanese - Sex identification of Japanese black bear, Ursus thibetanus japonicus, by PCR based on amelogenin gene
K Yamamoto, T Tsubota, T Komatsu, A Katayama, T Murase, Kita, I, T Kudo, JOURNAL OF VETERINARY MEDICAL SCIENCE, 64, 6, 505, 508, Jun. 2002
English - Sex identification of Japanese black bear, Ursus thibetanus japonicus, by PCR based on amelogenin gene
K Yamamoto, T Tsubota, T Komatsu, A Katayama, T Murase, Kita, I, T Kudo, JOURNAL OF VETERINARY MEDICAL SCIENCE, 64, 6, 505, 508, Jun. 2002
English - 「ワークショップ : 野生動物医学の最前線」の報告
坪田 敏男, Zoo and wildlife news = ズー・アンド・ワイルドライフニュース, 0, 14, 7, 8, 01 Jun. 2002
Japanese - ザンビア国のウシ及び野生レチュエ由来の肝蛭における形態学的及び分子遺伝学的解析
板垣 匡, 志茂 順子, 杉本 千尋, 吉田 光敏, 小沼 操, 坪田 敏男, 福士 秀人, 中里 幸和, 安田 準, 日本獣医学会学術集会講演要旨集, 133回, 71, 71, Mar. 2002
(公社)日本獣医学会, Japanese - ザンビア特産Kafue Lechwe(Kobus leche kafuensis)雄の生殖器形態と精子形成
岩崎 絢子, 吉田 光敏, ムワンザ・AM, パテル・OV, バイヤット・IM, シャカリマ・M, 坪田 敏男, 福士 秀人, 板垣 匡, 杉本 千尋, 小沼 操, 中里 幸和, 安田 準, 日本獣医学会学術集会講演要旨集, 133回, 138, 138, Mar. 2002
(公社)日本獣医学会, Japanese - Accumulation and Reproductive Affection of Endocrine Disruptors to the Wild Animal
TSUBOTA Toshio, TAKI Shizuko, SUDO Akiko, MURASE Tetsuma, NODA Ayako, MASEGI Toshiaki, MINAMOTO Nobuyuki, Japanese Journal of Zoo and Wildlife Medicine, 7, 1, 69, 74, Mar. 2002
It is being clarified that endocrine disruptors which were produced by human being accumulated without decomposition in the environment for a long time and affected reproduction of human and wild animals. DDT as a organochlorine pesticide, PCBs as industrial products, dioxins as non-intensive products and DES as a synthetic estrogen are categorized into the endocrine disruptor. Population decline of alligators in Lake Apopka in U.S.A., decrease of reproductive rate in mink and river otters, thinning of eggshell or decrease of hatching rate in raptors, large-number death in dolphin and seals..., Japanese Society of Zoo and Wildlife Medicine, Japanese - Paternity determination using DNA fingerprinting in captive Japanese black .bears (Ursus thibetanusjaponicus) （共著）
Jpn. J. Zoo Wildl. Med., 7, 103‐108, 2002 - 野生動物における内分泌攪乱化学物質の蓄積濃度と生殖への影響（共著） 2002
Jpn. J. Zoo Wildl. Med., 7, 69‐74, 2002 - 黒毛和種種雄牛より得た凍結-融解精子の先体反応におけるジアシルグリセロールの生成
村瀬 哲磨, 向島 幸司, 坂口 慎一, 大谷 健, 坪田 敏男, The Journal of Reproduction and Development, 47, Suppl., a17, a17, Dec. 2001
(公社)日本繁殖生物学会, Japanese - Changes in sex steroids, gonadotropins, prolactin, and inhibin in pregnant and nonpregnant Japanese black bears (Ursus thibetanus japonicus)
M Sato, T Tsubota, T Komatsu, G Watanabe, T Taya, T Murase, Kita, I, T Kudo, BIOLOGY OF REPRODUCTION, 65, 4, 1006, 1013, Oct. 2001
English - Changes in sex steroids, gonadotropins, prolactin, and inhibin in pregnant and nonpregnant Japanese black bears (Ursus thibetanus japonicus)
M Sato, T Tsubota, T Komatsu, G Watanabe, T Taya, T Murase, Kita, I, T Kudo, BIOLOGY OF REPRODUCTION, 65, 4, 1006, 1013, Oct. 2001
English - Bioaccumulation of lead in wildlife dependent on the contaminated environment of the Kafue flats
MS Syakalima, KC Choongo, P Chilonda, B Ahmadu, M Mwase, M Onuma, C Sugimoto, T Tsubota, H Fukushi, M Yoshida, T Itagaki, J Yasuda, Y Nakazato, BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 67, 3, 438, 445, Sep. 2001
English - Bioaccumulation of lead in wildlife dependent on the contaminated environment of the Kafue flats
MS Syakalima, KC Choongo, P Chilonda, B Ahmadu, M Mwase, M Onuma, C Sugimoto, T Tsubota, H Fukushi, M Yoshida, T Itagaki, J Yasuda, Y Nakazato, BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY, 67, 3, 438, 445, Sep. 2001
English - 海外における動物疾病の動向 ザンビアにおけるKafue lechwe(ウシ科)及び畜牛における結核に関する研究 その公衆衛生的意義を含んで(STUDIES ON TUBERCULOSIS AMONG KAFUE LECHWE AND CATTLE INCLUDING ITS PUBLIC HEALTH SIGNIFICANCE IN ZAMBIA)
パンディー・G.S., 野村 靖夫, 福士 秀人, 杉本 千尋, 小沼 操, 坪田 敏男, 吉田 光敏, 板垣 匡, 中里 幸和, 安田 準, 日本獣医学会学術集会講演要旨集, 132回, 59, 59, Sep. 2001
(公社)日本獣医学会, English - 海外における動物疾病の動向 ザンビアにおける家畜と野生動物の相互伝播性疾病に関する調査研究1.牛及びレチュエ由来の肝蛭における分子遺伝学的解析
板垣 匡, 志茂 順子, 杉本 千尋, 吉田 光敏, 小沼 操, 坪田 敏男, 福士 秀人, 中里 幸和, 安田 準, 日本獣医学会学術集会講演要旨集, 132回, 59, 59, Sep. 2001
(公社)日本獣医学会, Japanese - 犬精液の凍結において最終希釈倍率,最終精子濃度,一次平衡時間及び二次平衡時間が融解後の精液性状に及ぼす影響
岡野 司, 村瀬 哲磨, 坪田 敏男, 日本獣医学会学術集会講演要旨集, 132回, 222, 222, Sep. 2001
(公社)日本獣医学会, Japanese - Immunolocalization of steroidogenic enzymes in the corpus luteum and placenta of the Japanese black bear, Ursus thibetanus japonicus, during pregnancy
T Tsubota, S Taki, K Nakayama, JI Mason, S Kominami, N Harada, Kita, I, REPRODUCTION, 121, 4, 587, 594, Apr. 2001
English - An investigation of heavy metal exposure and risks to wildlife in the Kafue flats of Zambia
M Syakalima, K Choongo, Y Nakazato, M Onuma, C Sugimoto, M Tsubota, H Fukushi, M Yoshida, T Itagaki, J Yasuda, JOURNAL OF VETERINARY MEDICAL SCIENCE, 63, 3, 315, 318, Mar. 2001
English - ヒトと野生動物の関わり 新興感染症と有害化学物質汚染 日本の野生動物における内分泌撹乱化学物質汚染の現状
坪田 敏男, 須藤 明子, 柵木 利昭, 源 宣之, 岩見 恭子, 日本獣医学会学術集会講演要旨集, 131回, 112, 112, Mar. 2001
(公社)日本獣医学会, Japanese - Characterization of semen collected from beagles and captive Japanese black bears (Ursus thibetanus japonicus)
E Kojima, H Tsuruga, T Komatsu, T Murase, T Tsubota, Kita, I, THERIOGENOLOGY, 55, 3, 717, 731, Feb. 2001
English - Seasonal changes in testicular steroidogenesis and spermatogenesis in a northern fur seal, Callorhinus ursinus
Toshio Tsubota, Tomomi Nagashima, Kaoru Kohyama, Kenji Maejima, Tetsuma Murase, Isao Kita, Journal of Reproduction and Development, 47, 6, 415, 420, 2001
The Japanese Society of Animal Reproduction (JSAR), English - Generation of diacylglycerol during the acrosome reaction induced by Ca2+ and Ca2+ lonophore A23187 in frozen-thawed spermatozoa from fertile and subfertile japanese black bulls
Tetsuma Murase, Koji Mukohjima, Shin-Ichi Sakaguchi, Tsuyoshi Ohtani, Toshio Tsubota, Journal of Reproduction and Development, 47, 5, 311, 316, 2001
The Japanese Society of Animal Reproduction (JSAR), English - Characterization of frozen-thawed Japanese black bull spermatozoa by standard semen analysis, mucus penetration test and the ability to undergo the acrosome reaction in response to calcium and the calcium ionophore A23187
Tetsuma Murase, Koji Mukohjima, Shin-Ichi Sakaguchi, Tsuyoshi Ohtani, Toshio Tsubota, Isao Kita, Journal of Reproduction and Development, 47, 4, 237, 243, 2001
The Japanese Society of Animal Reproduction (JSAR), English - Seasonal changes in testicular steroidogenesis and spermatogenesis in a northern fur seal, Callorhinus ursinus
Toshio Tsubota, Tomomi Nagashima, Kaoru Kohyama, Kenji Maejima, Tetsuma Murase, Isao Kita, Journal of Reproduction and Development, 47, 6, 415, 420, 2001
The Japanese Society of Animal Reproduction (JSAR), English - Generation of diacylglycerol during the acrosome reaction induced by Ca2+ and Ca2+ lonophore A23187 in frozen-thawed spermatozoa from fertile and subfertile japanese black bulls
Tetsuma Murase, Koji Mukohjima, Shin-Ichi Sakaguchi, Tsuyoshi Ohtani, Toshio Tsubota, Journal of Reproduction and Development, 47, 5, 311, 316, 2001
The Japanese Society of Animal Reproduction (JSAR), English - Characterization of frozen-thawed Japanese black bull spermatozoa by standard semen analysis, mucus penetration test and the ability to undergo the acrosome reaction in response to calcium and the calcium ionophore A23187
Tetsuma Murase, Koji Mukohjima, Shin-Ichi Sakaguchi, Tsuyoshi Ohtani, Toshio Tsubota, Isao Kita, Journal of Reproduction and Development, 47, 4, 237, 243, 2001
The Japanese Society of Animal Reproduction (JSAR), English - Influence of the different batches of estrous cervical mucus mixed for homogenization on penetration by spermatozoa in cattle
Tetsuma Murase, Koji Mukohjima, Shin-Ichi Sakaguchi, Tsuyoshi Ohtani, Toshio Tsubota, Isao Kita, Journal of Reproduction and Development, 47, 2, 109, 112, 2001
The Japanese Society of Animal Reproduction (JSAR), English - 黒毛和牛精子における子宮頸管粘液への侵入およびCa2+-イオノホアによる先体反応と受胎性との関連
村瀬 哲磨, 向島 幸司, 坂口 慎一, 大谷 健, 坪田 敏男, 喜多 功, The Journal of Reproduction and Development, 46, Suppl., a45, a45, Dec. 2000
(公社)日本繁殖生物学会, Japanese - ニホンツキノワグマにおける着床遅延中の卵巣のステロイドおよびインヒビン合成に関する免疫組織化学的研究
佐藤 美穂, 坪田 敏男, 渡辺 元, 田谷 一善, 小松 武志, 村瀬 哲磨, 喜多 功, 工藤 忠明, The Journal of Reproduction and Development, 46, Suppl., a41, a41, Dec. 2000
(公社)日本繁殖生物学会, Japanese - 授乳及び非授乳中のニホンツキノワグマ(Ursus thibetanus japonicus)における血清プロジェステロン,エストラジオール-17β,黄体形成ホルモン,プロラクチン濃度の変化
佐藤 美穂, 中野 典子, 坪田 敏男, 小松 武志, 村瀬 哲磨, 喜多 功, 工藤 忠明, The Journal of Reproduction and Development, 46, 5, 301, 308, Oct. 2000
(公社)日本繁殖生物学会, English - 欧米の野生動物医学事情 : 2カ月間の研修より
坪田 敏男, Zoo and wildlife news = ズー・アンド・ワイルドライフニュース, 0, 10, 9, 12, 01 Jun. 2000
Japanese - Serum progesterone and estradiol-17 beta concentrations in captive and free-ranging adult female Japanese black bears (Ursus thibetanus japonicus)
M Sato, T Tsubota, K Yamamoto, T Komatsu, Y Hashimoto, A Katayama, T Hazumi, Kita, I, T Kudo, JOURNAL OF VETERINARY MEDICAL SCIENCE, 62, 4, 415, 420, Apr. 2000
English - 糞分析からみたニホンツキノワグマ(┣DBUrsus(/)-┫DB ┣DBthibetanus(/)-┫DB ┣DBjaponicus(/)-┫DB)の食性-岐阜県本巣郡根尾村における事例-(共著)
堀内みどり, 中森研, 48, 149, 152, 2000 - 和牛精子が発情期の子宮頸管粘液へ侵入する能力を測定する方法の簡便化
村瀬 哲磨, 向島 幸司, 坂口 慎一, 坪田 敏男, 喜多 功, The Journal of Reproduction and Development, 45, 6, 425, 428, Dec. 1999
(公社)日本繁殖生物学会, English - 成熱雌ニホンツキノワグマにおける血清中FSH,LH,インヒビン,プロジェステロン及びエストラジオール-17β濃度の周年変化
佐藤 美穂, 坪田 敏男, 小松 武志, 渡辺 元, 田谷 一善, 村瀬 哲磨, 喜多 功, 工藤 忠明, The Journal of Reproduction and Development, 45, Suppl., a34, a34, Dec. 1999
(公社)日本繁殖生物学会, Japanese - Chemical characterization of milk oligosaccharides of the Japanese black bear, Ursus thibetanus japonicus
T Urashima, W Sumiyoshi, T Nakamura, Arai, I, T Saito, T Komatsu, T Tsubota, BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS, 1472, 1-2, 290, 306, Oct. 1999
English - 和牛精子が発情期子宮頸管粘液へ侵入する能力
村瀬 哲磨, 向島 幸司, 坂口 慎一, 坪田 敏男, 喜多 功, 日本獣医学会学術集会講演要旨集, 128回, 230, 230, Sep. 1999
(公社)日本獣医学会, Japanese - A simplified technique to determine the ability of Spermatozoa to penetrate the estrous cervical mucus in Japanese beef cattle
Tetsuma Murase, Koji Mukohjima, Shin-Ichi Sakaguchi, Toshio Tsubota, Isao Kita, Journal of Reproduction and Development, 45, 6, 425, 428, 1999
The Japanese Society of Animal Reproduction (JSAR), English - Sex steroid and prolactin profiles in male American black bears (Ursus americanus) during denning
T Tsubota, DL Garshelis, RA Nelson, JM Bahr, JOURNAL OF VETERINARY MEDICAL SCIENCE, 61, 1, 81, 83, Jan. 1999
English - 冬眠中のアメリカクロクマにおける性ステロイドホルモン及びプロラクチン濃度の変化
坪田 敏男, Garshelis D.L., Nelson R.A., Bahr J.M., The Journal of Veterinary Medical Science, 61, 1, 81, 83, Jan. 1999
(公社)日本獣医学会, English - イヌの精巣におけるステロイド代謝酵素3βHSD及びP450aromのmRNAの発現
坪田 敏男, Morrey Craig E., 長濱 嘉孝, 村瀬 哲磨, 喜多 功, The Journal of Reproduction and Development, 44, 6, a48, a48, Dec. 1998
(公社)日本繁殖生物学会, Japanese - 飼育下及び野生下における成熟雌ニホンツキノワグマ(Ursus thibetanus japonicus)の血清プロジェステロン濃度の測定
佐藤 美穂, 坪田 敏男, 山本 かおり, 小松 武志, 橋本 幸彦, 片山 敦司, 羽澄 俊裕, 喜多 功, The Journal of Reproduction and Development, 44, 6, a55, a55, Dec. 1998
(公社)日本繁殖生物学会, Japanese - Serum progesterone, oestradiol, luteinizing hormone and prolactin profiles in the female black bear (Ursus americanus)
T Tsubota, L Howell-Skalla, WR Boone, DL Garshelis, JM Bahr, ANIMAL REPRODUCTION SCIENCE, 53, 1-4, 107, 118, Oct. 1998
English - Immunohistochemical demonstration of cytoskeletal proteins in the testis of the Japanese black bear, Ursus thibetanus japonicus
T Komatsu, Y Yamamoto, Y Atoji, T Tsubota, Y Suzuki, ANATOMIA HISTOLOGIA EMBRYOLOGIA-JOURNAL OF VETERINARY MEDICINE SERIES C-ZENTRALBLATT FUR VETERINARMEDIZIN REIHE C, 27, 3, 209, 213, Jun. 1998
English - Circumanal glands of the dog: A new classification and cell degeneration
Y Atoji, Y Yamamoto, T Komatsu, Y Suzuki, T Tsubota, ANATOMICAL RECORD, 250, 3, 251, 267, Mar. 1998
English - Ecological and physiological studies of the Japanese black bear, Ursus thibetanus japonicus
TSUBOTA Toshio, MIZOGUCHI Noriyasu, KITA Isao, Japanese Journal of Zoo and Wildlife Medicine, 3, 1, 17, 24, Mar. 1998
The Japanese black bear Ursus thibetanus japonicus, a large terrestrial mammal inhabits Honshu, Shikoku and Kyushu islands of Japan. However, Kyushu populations face extinction while populations on Shikoku island, in regions of Chugoku, and on the Kii peninsula are endangered. Ecological surveys such as direct observation, fecal analysis after field-sign detection and radio-tracking were carried out on Japanese black bears in Shirakawa Village, Gifu Prefecture in 1990-1994. Food habits of Japanese black bears in the spring and autumn related to the beech forest habitat of Shirakawa Village...., Japanese Society of Zoo and Wildlife Medicine, Japanese - ツキノワグマの生態と保護管理
はくさん, 25, 3, 7, 1998 - Bears as induced ovulators - A preliminary study
WR Boone, JC Catlin, KJ Casey, ET Boone, PS Dye, RJ Schuett, JO Rosenberg, T Tsubota, JM Bahr, URSUS, VOL 10 - 1998, 10, 503, 505, 1998
English - Seasonal changes in subcellular structures of Leydig and Sertoli cells in the Japanese black bear, Ursus thibetanus japonicus
T Komatsu, Y Yamamoto, Y Atoji, T Tsubota, Y Suzuki, ARCHIVES OF HISTOLOGY AND CYTOLOGY, 60, 3, 225, 234, Aug. 1997
English - Seasonal changes in subcellular structures of Leydig and Sertoli cells in the Japanese black bear, Ursus thibetanus japonicus
T Komatsu, Y Yamamoto, Y Atoji, T Tsubota, Y Suzuki, ARCHIVES OF HISTOLOGY AND CYTOLOGY, 60, 3, 225, 234, Aug. 1997
English - Seasonal changes in the immunolocalization of steroidogenic enzymes in the testes of the Japanese black bear (Ursus thibetanus japonicus)
T Komatsu, T Tsubota, Y Yamamoto, Y Atoji, Y Suzuki, JOURNAL OF VETERINARY MEDICAL SCIENCE, 59, 7, 521, 529, Jul. 1997
English - ブナの豊凶がツキノワグマの食性に与える影響-ブナとミズナラの種子落下量の年次変動に関連して-(共著)
哺乳類科学, 36, 33, 44, 1997 - Seasonal changes in spermatogenesis and testicular steroidogenesis in the male black bear Ursus americanus
T Tsubota, L HowellSkalla, H Nitta, Y Osawa, JI Mason, PG Meiers, RA Nelson, JM Bahr, JOURNAL OF REPRODUCTION AND FERTILITY, 109, 1, 21, 27, Jan. 1997
English - Immunolocalization of steroidogenic enzymes in the corpus luteum and the placenta of Japanese black bears, Ursus thibetanus japonicus during pregnancy
T Tsubota, S Taki, K Nakayama, JL Mason, S Kominami, N Harada, Kita, I, BIOLOGY OF REPRODUCTION, 56, 30, 30, 1997
English, Summary international conference - Intraovarian immunolocalization of steroidogenic enzymes in a Hokkaido Brown bear, Ursus arctos yesoensis during the mating season
H Araki, T Tsubota, N Maeda, N Harada, S Kominami, JJ Mason, Kita, I, JOURNAL OF VETERINARY MEDICAL SCIENCE, 58, 8, 787, 790, Aug. 1996
English - Gravid sclerosis in the myo- and endometrial vessels of the Japanese serow, Capricornis crispus, with special reference to past gestation
KITA Isao, SUZUKI Noriko, NIWA Norio, TSUBOTA Toshio, Japanese Journal of Zoo and Wildlife Medicine, 1, 2, 113, 117, Aug. 1996
Histological studies on the artery of the uterine wall were performed in 30 adult female Japanese serows, Capricornis crispus. Gravid sclerosis was found in the myo- and endometrial arteries of parous serows. In nulliparous adult females, the internal elastic lamina is thin and poorly indented, whereas in the females that kidded one to three times, it is thick and full of indentation. In females that kidded more than four times, double- or multilayered elastic laminae, hyperplastic elastic fibers and degenerated nuclei of smooth muscle cells in the media were observed. In females that kidde..., Japanese Society of Zoo and Wildlife Medicine, Japanese - Intraovarian immunolocalization of steroidogenic enzymes in a Hokkaido Brown bear, Ursus arctos yesoensis during the mating season
H Araki, T Tsubota, N Maeda, N Harada, S Kominami, JJ Mason, Kita, I, JOURNAL OF VETERINARY MEDICAL SCIENCE, 58, 8, 787, 790, Aug. 1996
English - Spermatogenic cycle in the testis of the Japanese black bear (Selenarctos thibetanus japonicus)
T Komatsu, Y Yamamoto, T Tsubota, Y Atoji, Y Suzuki, JOURNAL OF VETERINARY MEDICAL SCIENCE, 58, 4, 329, 335, Apr. 1996
English - Spermatogenic cycle in the testis of the Japanese black bear (Selenarctos thibetanus japonicus)
T Komatsu, Y Yamamoto, T Tsubota, Y Atoji, Y Suzuki, JOURNAL OF VETERINARY MEDICAL SCIENCE, 58, 4, 329, 335, Apr. 1996
English - Reproductive Evaluation of Japanese Black Bears(Selenarctos thibetanus japonicus)by Observation of the Ovary and Uterus
KATAYAMA Atsushi, TSUBOTA Toshio, YAMADA Fumio, KITA Isao, TIBA Tosiro, Japanese Journal of Zoo and Wildlife Medicine, 1, 1, 26, 32, Feb. 1996
Female genital organs from 19 Japanese black bears(Selenarctos thibetanus japonicus)were collected at Gifu and Kyoto prefecture during the period from March 1991 to August 1993. Both weight and volume of the ovaries increased according to adding of the age. The existence of corpora lutea and its involuted matters showed Japanese black bear sexually matured at the age of four, though there were differences among individuals. From observation of the genital organs, the mean value of ovulation was indicated 1.89 and that of implantation 2.00. The mean value of cubs having observed by hunters w..., Japanese Society of Zoo and Wildlife Medicine, Japanese - Changes in steroidogenic sites during pregnancy in the domestic cat
T Tsubota, H Araki, JI Matson, S Kominami, N Harada, Kita, I, BIOLOGY OF REPRODUCTION, 54, 262, 262, 1996
English, Summary international conference - Validity of retrograde corpora lutea of pregnancy as an index of past gestation in sika deer, Cervus nippon
Kita, I, M Eguchi, S Takatsuki, T Koizumi, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 57, 6, 1029, 1033, Dec. 1995
English - Validity of retrograde corpora lutea of pregnancy as an index of past gestation in sika deer, Cervus nippon
Kita, I, M Eguchi, S Takatsuki, T Koizumi, T Tsubota, JOURNAL OF VETERINARY MEDICAL SCIENCE, 57, 6, 1029, 1033, Dec. 1995
English - ANNUAL CHANGES IN SERUM CONCENTRATIONS OF PROLACTIN IN CAPTIVE MALE BLACK BEARS (URSUS-AMERICANUS)
T TSUBOTA, RA NELSON, JD THULIN, L HOWELL, JM BAHR, JOURNAL OF REPRODUCTION AND FERTILITY, 104, 2, 187, 191, Jul. 1995
English - Wintering of bears
羽澄 俊裕, 間野 勉, 近藤 宣昭, 坪田 敏男, Honyurui Kagaku (Mammalian Science), 34, 2, 158, 162, 30 Mar. 1995
The Mammal Society of Japan, Japanese - IMMUNOLOCALIZATION OF STEROIDOGENIC ENZYMES P450SCC, 3-BETA-HSD, P450C17 AND P450AROM IN THE CORPUS-LUTEUM OF THE HOKKAIDO BROWN BEAR (URSUS-ARCTOS YESOENSIS) IN RELATION TO DELAYED IMPLANTATION
T TSUBOTA, H NITTA, Y OSAWA, JI MASON, KITA, I, T TIBA, JM BAHR, JOURNAL OF REPRODUCTION AND FERTILITY, 101, 3, 557, 561, Aug. 1994
English - Puberty and Stem Cell for the Initiation and Resumption of Spermatogenesis in the Male Japanese Black Bear (Selenarctos thibetanus japonicus)
Takeshi Komatsu, Toshio Tsubota, Tosiro Tiba, Mayumi Kishimoto, Shin-Itiro Hamasaki, Journal of Reproduction and Development, 40, 6, j65-j71, 1994
English - Parturition and postnatal development in the captive Hokkaido brown bear, Ursus arctos yesoensis(共著)
Toshio TSUBOTA, Naoko MAEDA, Hiroshi KANAGAWA, J. Mamm. Soc. Japan, 19, 2, 75, 82, 1994
This study was carried out to clarify the developmental biology of Hokkaido brown bears Ursus arctos yesoensis from birth to approximately 90-day-old. Though the birth date of 107 litters ranged from 11 January to 1 March, 91% of the cubs were born between 17 January and 5 February. The body weight of 40 neonates was 419±40 g (mean±SE) and did not differ significantly between the sexes (p>0.05). Mean litter size was 1.82±0.70 (SE). Mean body weight gain per day, an indicator of bear development, was calculated for 192 cubs from the date and body weight at birth and at about 90-day-old. The body weight gain varied greatly among individuals (range: 0.018-0.130 kg/day) and tended to be smaller as litter size increased. The body weight gain differed significantly (p<0.01) between the sexes when there was only one cub, but not when there were two or more cubs. The mean intake of calories per unit body weight gain from birth to 68 days after birth, was calculated at 4,000 kcal/kg for the hand-reared cubs.
, The Mammal Society of Japan, English - SERUM ESTRADIOL-17-BETA, PROGESTERONE, LUTEINIZING-HORMONE AND PROLACTIN PROFILES DURING THE LUTEAL-PHASE IN BLACK BEARS, URSUS-AMERICANUS
T TSUBOTA, WR BOONE, DL GARSHELIS, RA NELSON, JM BAHR, BIOLOGY OF REPRODUCTION, 50, 82, 82, 1994
English, Summary international conference - IMMUNOLOCALIZATION OF STEROIDOGENIC ENZYMES, P450SCC, 3-BETA-HSD, P450C17, AND P450AROM IN THE HOKKAIDO BROWN BEAR (URSUS-ARCTOS YESOENSIS) TESTIS
T TSUBOTA, H NITTA, Y OSAWA, JI MASON, KITA, I, T TIBA, JM BAHR, GENERAL AND COMPARATIVE ENDOCRINOLOGY, 92, 3, 439, 444, Dec. 1993
English - REGULARITIES AND IRREGULARITIES IN THE STRUCTURE OF THE SEMINIFEROUS EPITHELIUM IN THE DOMESTIC-FOWL (GALLUS-DOMESTICUS) .2. COORDINATION BETWEEN GERM-CELL ASSOCIATIONS
T TIBA, Y SHIMIZU, KITA, I, T TSUBOTA, ANATOMIA HISTOLOGIA EMBRYOLOGIA-JOURNAL OF VETERINARY MEDICINE SERIES C-ZENTRALBLATT FUR VETERINARMEDIZIN REIHE C, 22, 3, 254, 263, Sep. 1993
English - REGULARITIES AND IRREGULARITIES IN THE STRUCTURE OF THE SEMINIFEROUS EPITHELIUM IN THE DOMESTIC-FOWL (GALLUS-DOMESTICUS) .1. SUGGESTION OF THE PRESENCE OF THE SEMINIFEROUS EPITHELIAL CYCLE
T TIBA, K YOSHIDA, M MIYAKE, K TSUCHIYA, KITA, I, T TSUBOTA, ANATOMIA HISTOLOGIA EMBRYOLOGIA-JOURNAL OF VETERINARY MEDICINE SERIES C-ZENTRALBLATT FUR VETERINARMEDIZIN REIHE C, 22, 3, 241, 253, Sep. 1993
English - Morphological Characteristics of the Ovary, Uterus and Embryo during the Delayed Implantation Period in the Hokkaido Brown Bear (Ursus arctos yesoensis)
Toshio Tsubota, Hiroshi Kanagawa, Journal of Reproduction and Development, 39, 4, 325, 331, 1993
English - SERUM PROGESTERONE CONCENTRATIONS USING P-EIA KIT IN CAPTIVE AND FREE-RANGING HOKKAIDO BROWN BEARS, URSUS-ARCTOS-YESOENSIS
T TSUBOTA, H KANAGAWA, K YAMAMOTO, T MANO, M YAMANAKA, KITA, I, T TIBA, JOURNAL OF VETERINARY MEDICAL SCIENCE, 54, 1, 1, 5, Feb. 1992
English - SERUM PROGESTERONE CONCENTRATIONS USING P-EIA KIT IN CAPTIVE AND FREE-RANGING HOKKAIDO BROWN BEARS, URSUS-ARCTOS-YESOENSIS
T TSUBOTA, H KANAGAWA, K YAMAMOTO, T MANO, M YAMANAKA, KITA, I, T TIBA, JOURNAL OF VETERINARY MEDICAL SCIENCE, 54, 1, 1, 5, Feb. 1992
English - IMMOBILIZATION OF THE FREE-RANGING HOKKAIDO BROWN BEAR, URSUS-ARCTOS-YESOENSIS WITH KETAMINE-HYDROCHLORIDE AND XYLAZINE HYDROCHLORIDE
T TSUBOTA, K YAMAMOTO, T MANO, M YAMANAKA, H KANAGAWA, JOURNAL OF VETERINARY MEDICAL SCIENCE, 53, 2, 321, 322, Apr. 1991
English - EMBRYO RECOVERY DURING DELAYED IMPLANTATION IN THE CAPTIVE HOKKAIDO BROWN BEAR, URSUS-ARCTOS-YESOENSIS
T TSUBOTA, Y TAKAHASHI, H KANAGAWA, K GOHDA, JOURNAL OF VETERINARY MEDICAL SCIENCE, 53, 1, 141, 142, Feb. 1991
English, Introduction scientific journal - Embryo Recovery during Delayed Implantation in the Captive Hokkaido Brown Bear, Ursus arctos yesoensis
Toshio Tsubota, Yoshiyuki Takahashi, Hiroshi Kanagawa, Katsumi Gohda, Journal of Veterinary Medical Science, 53, 1, 141, 142, 1991
English - 雄エゾヒグマにおける性成熟と精子形成の季節的変動
坪田 敏男, 日本獣医学会学術集会講演要旨集, 110回, 226, 226, Oct. 1990
(公社)日本獣医学会, Japanese - Studies on reproductive physiology of Hokkaido brown bear, Ursus arctos yesoensis
Jpn. J. Anim. Reprod, 36,1-10, 1990 - Annual Changes in Serum Testosterone Levels and Spermatogenesis in the Hokkaido Brown Bear,Ursus arctos yesoensis
TSUBOTA T, Journal of the Mammalogical Society of Japan, 14, 1, 11, 17, Jul. 1989
Mammalogical Society of Japan, English - エゾヒグマにおける着床遅延期間の卵巣,子宮および胚の形態
坪田 敏男, 日本獣医学会学術集会講演要旨集, 105回, 261, 261, Apr. 1988
(公社)日本獣医学会, Japanese - エゾヒグマの胚,胎仔および新生仔の発育について
坪田 敏男, 日本獣医学会学術集会講演要旨集, 104回, 219, 219, Jul. 1987
(公社)日本獣医学会, Japanese - エゾヒグマの血清テストステロン値と精子形成の季節変化
坪田 敏男, 哺乳動物学雑誌, 11, 1〜2, 82, 83, May 1986
(一社)日本哺乳類学会, Japanese - エゾヒグマにおける白体,胎盤痕からの経産歴判定の試み
坪田 敏男, 日本獣医学会学術集会講演要旨集, 101回, 235, 235, Mar. 1986
(公社)日本獣医学会, Japanese - REPRODUCTIVE PHYSIOLOGY OF EZO BROWN BEAR, URSUS ARCTOS YESOENSIS, WITH PARTICULAR REFERENCE TO REPRODUCTIVE CYCLE
TSUBOTA Toshio, Japanese journal of veterinary research, 33, 1, 100, 100, 30 Apr. 1985
Hokkaido University, English - Ultrasonogram of the fetus of Hokkaido brown bear.
TSUBAKI Shigeru, TOO Kimehiko, TSUBOTA Toshio, TAKAHASHI Yoshiyuki, KANAGAWA Hiroshi, The Japanese journal of animal reproduction, 31, 2, 90, 92, 1985
Pregnancy diagnosis by the ultrasonogram method was carried out in a captive 13 years old female Hokkaido brown bear. Two fetuses were detected in the left abdomen. The fetus transverse diameter was 5.2 cm and the heart rate was 180 beats/min. Further improvement is necessary to diagnose the number of fetuses by our method, for she gave birth to 3 cubs 4 days later., THE SOCIETY FOR REPRODUCTION AND DEVELOPMENT, Japanese - クマ牧場に集団飼育されているエゾヒグマの交尾行動の観察
坪田 敏男, 家畜繁殖学雑誌, 29, 5, 50, 51, Dec. 1983
(公社)日本繁殖生物学会, Japanese
Books and other publications
- カリブー
Aglukark, Dorothy, Aglukark, David, Sandland, Amanda, 坪田, 敏男
丸善出版, Jan. 2020, 9784621304488, 21p, Japanese - ホッキョクグマ : 生態と行動の完全ガイド
Derocher, Andrew E., Lynch, Wayne, 坪田, 敏男, 山中, 淳史, 中下, 留美子, 中島, 亜美, Taylor, Kyle
東京大学出版会, Oct. 2014, 9784130602266, 280p, Japanese - JBN緊急クマシンポジウム&ワークショップ報告書 : 2006年ツキノワグマ大量出没の総括とJBNからの提言
坪田 敏男, 日本クマネットワーク(JB
日本クマネットワーク, 2007, 4990323025, Japanese - 冬眠する哺乳類(共著)
東京大学出版会, 2000 - 小動物の繁殖と新生子マニュアル(Small Animal Reproduction and Neonatologyの翻訳本)(共著)
学窓社, 2000 - 小動物の繁殖と新生子マニュアル
Simpson Gillian M, England, Gary C. W, Harvey Mike, 稲葉 俊夫, 坪田 敏男, 村瀬 哲磨, 津曲 茂久
学窓社, 2000, 487362097X, Japanese - 季節繁殖(共著)
哺乳類の生殖生物学,学窓社, 1999 - ヒグマの妊娠・出生・子育て(共著)
動物にみる妊娠・出産・子育て,メディカ出版, 1999 - 小さくうんで,大きく育てる(共著)
ヒグマの原野,フレーベル館, 1998 - 哺乳類の生物学(3)生理(単著)
東京大学出版会, 1998 - 哺乳類の生物学 (3)生理
東京大学出版会, 1998 - ヒグマの冬眠と繁殖生理(共著)
日本動物大百科1哺乳類I, 1996 - クマ
獣医繁殖学, 1995 - 野生哺乳動物の性行動:エゾヒグマの観察(共著)
哺乳動物の生殖行動, 1992 - Sexual behavior of wild mammals : Hokkaido brown bear
1992
Courses
Affiliated academic society
Works
- ツキノワグマ生息実態調査報告書(共著)、岐阜県根尾村
2000 - 訪問紀:サンディエゴ動物園希少種繁殖センター(CRES)、J. Reprod. Dev. 46/4:(]G0008[)-(]G0009[)
2000 - 欧米の野生動物医学事情-2ヵ月間の研修より-、Zoo and Wildlife News 10:9-12
2000 - 内分泌攪乱化学物質による野生生物影響実態調査マニュアル(共著)
1999 - 環境ホルモンと生殖異常(単著)環境保全(岐阜大学環境保全広報)創刊号:5-10
1999 - 第21回総会記念講演「環境ホルモンと生殖異常」(単著)自治研ぎふ(岐阜県地方自治研究センター広報)64:12-20
1999 - 野生生物のダイオキシン類汚染状況調査マニュアル(共著)
1998 - ジャイアントパンダの繁殖に関するワークショップに参加して,岐阜県獣医師会報37:77-79
1997 - ニホンジカ黄体退縮物の経産指標としての有効性,岐阜県獣医師会報36:20-25
1996 - クマ,畜産の研究50(I):145-150
1996 - 天然林におけるニホンツキノワグマの生息可能密度-ブナの豊凶に伴うツキノワグマの春と秋の食性の年次変動-、第4期プロ・ナトゥーラ・ファンド助成成果報告書17-25
1995 - 岐阜県ツキノワグマ個体群指標調査報告書(岐阜県林政部自然環境保全課編),35pp
1995 - クマの繁殖生理、はばたき(神戸市立王子動物園発行)36:9-10
1994 - ツキノワグマによる白山高山帯の利用について,天然林におけるツキノワグマの生態調査報告書(1989-1994年):19-26
1994 - アメリカでの研究生活を終えて、月輪:75-78
1994 - グリズリーの楽園-カトマイ国立公園-、Field Note40:3-6
1993 - ミネソタ州のクロクマ調査、月輪5:78-81
1993 - アメリカでのクマ研究事情Part1-イリノイでのクマ研究-、月輪4:83-85
1992 - SSRに参加して-とくにアメリカでの野生動物の繁殖生理学的研究、比較内分泌学会ニュース67:7-8
1992 - Denali National Parkでのクマの研究と保護管理、Field Note36:13-16
1992 - エゾヒグマの繁殖生理、遺伝45(7):77-81
1991 - クマ類の繁殖特性、日本科学者会議岐阜支部会報38:3-22
1991 - 日本産クマ類の研究概観、高教研会誌、20:96-99
1991 - 野生クマへの研究アプローチ-野生動物との共存への道-、岐阜県獣医師会報、28:9-14
1991 - 日本産クマ類の研究紹介、岐阜県高等学校教育研究会生物教育研究部会雑誌34:8-15
1990 - 1989年ツキノワグマ夏季白山高山帯調査報告、月輪2:14-20
1990 - 1989年白川村ツキノワグマ生態調査報告(共著)、月輪2:1-11
1990
Research Themes
- Muscle Atrophy Resistance in Hibernating Animals
Grants-in-Aid for Scientific Research
01 Apr. 2022 - 31 Mar. 2026
宮崎 充功, 坪田 敏男, 山口 良文, 渡邊 正知, 下鶴 倫人
冬眠動物には、5-6ヵ月におよぶ冬眠前後で筋肉量や筋力がほとんど衰えない、骨格筋萎縮耐性ともいえる未解明の生理機能が存在する。本研究では冬眠を「長期間の身体不活動状態の継続」と捉え、冬眠動物がいかなる適応機構を用いて骨格筋萎縮耐性を獲得するのかを解明し、さらに非冬眠動物のマウスで “衰えない筋肉” を再現させるのが本研究の目的である。この目標を達成するために、本研究では特に課題1) 冬眠動物の骨格筋に共通して発現誘導・抑制される遺伝子群(DEGs)の網羅的解析を基盤とし、課題2) 骨格筋衛星細胞を用いて冬眠誘導性遺伝子の発現制御による筋タンパク質代謝調節機構を明らかにする。さらに課題3) 冬眠誘導性遺伝子のマウス骨格筋でのin vivo機能解析を通じ、冬眠動物の骨格筋萎縮耐性能を非冬眠動物であるマウス骨格筋で再現させる。
研究開始2年目である2023年度においては、2022年度に完了させた冬眠動物の骨格筋における冬眠誘導性遺伝子の探索結果を基盤とし、絞り込みを行った候補遺伝子の全身性ノックアウトマウスおよび骨格筋組織特異的ノックアウトマウスの作出に着手した。ファウンダーマウスはすでに作出を完了しており、現在その機能解析を進行中である。また冬眠動物骨格筋からの組織幹細胞単離方法の確立および低温誘導性細胞死に対する抵抗性の分子機構解明についても検討を進めており、その結果の一部については国際学会および招待講演にて報告をしている。
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hiroshima University, 23K24697 - Novel Strategy to Prevent Skeletal Muscle Atrophy Based on "Muscle Atrophy Resistance" in Hibernating Animals
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2022 - 31 Mar. 2026
宮崎 充功, 坪田 敏男, 山口 良文, 渡邊 正知, 下鶴 倫人
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hiroshima University, 22H03439 - オスグマの行動を決めるもの－個体レベルの行動・生理研究－
科学研究費助成事業
01 Apr. 2022 - 31 Mar. 2025
山崎 晃司, 坪田 敏男, 小池 伸介
これまでの研究で，ツキノワグマは秋期の飽食期に蓄えた体脂肪を，冬眠期間中のみならず，冬眠明け後の春から夏にかけても継続して利用することが明らかになってきた。春から夏は，高栄養で採食効率の良い食物の獲得が難しいことがその理由である。そのためクマは，動き回るとエネルギー収支がマイナスになってしまう夏期後半には，活動を停滞させる傾向を突き止めた。一方で，オスについては断片的な行動と生理に関するデータしか得られていないが，このような傾向が当てはまらない個体も多い。本研究では，オスの齢級に着目しながら，春から秋にかけての行動と生理に関する特徴を個体レベルで明らかにする。
研究対象地域は，奥多摩山地および足尾・日光山地の一帯のそれぞれ数100km2の範囲である。2023年度は，奥多摩山地でオス1頭，足尾・日光山地でオス4頭の計5頭にイリジウム通信型の軽量型GPS首輪あるいはビデカム付きGPS首輪（ドイツVectronic社）を装着した。首輪には3軸アクセラレータが内蔵されており，クマの行動区分をモデル解析により行える。2022年度捕獲個体の背部皮下に挿入した心拍・体温計（アイスランドStar-Oddi社）の再回収を試みたが成功には至っていない。
また，繁殖に関わるマーカーとして，糞中のテストステロン代謝物質の分析を，首輪装着個体の集中利用場所で可能な限り迅速に糞を採取して行った。さらに，同様に糞中のコルチゾルをマーカーとして用いてストレスと栄養状態の評価を行っている。個体の大きな移動前後の食性比較では，採集した糞を用い，内容物の量とその栄養学的評価を行う。並行して，日立市かみね動物園の飼育グマを用いた，性ホルモンの測定値評価を2023年度も実施した。
日本学術振興会, 基盤研究(B), 東京農業大学, 23K23654 - オスグマの行動を決めるもの－個体レベルの行動・生理研究－
科学研究費助成事業 基盤研究(B)
01 Apr. 2022 - 31 Mar. 2025
山崎 晃司, 坪田 敏男, 小池 伸介
日本学術振興会, 基盤研究(B), 東京農業大学, 22H02389 - Do lethal infectious diseases invade into endangered species in Nepal? - Conservation science in biodiversity hotspot -
Grants-in-Aid for Scientific Research Fund for the Promotion of Joint International Research (Fostering Joint International Research (B))
07 Oct. 2021 - 31 Mar. 2024
坪田 敏男, THAPA JEEWAN, 大沼 学, 鍋島 圭, 鈴木 定彦
本年度は、新型コロナウイルス感染症のパンデミックにより研究対象国ネパールに行くことができなかったため、研究はほとんど進んでいない。しかしながら、海外渡航再開に向けて、日本でできる準備を進めた。
まず、ネパールの海外共同研究者であるDr. Naresh SubediおよびDr. Rabin Kadariyaとオンラインで打ち合わせ会議を実施した。研究の全体像、渡航可能となった際のおおよそのスケジュール、本研究プロジェクトに参加する大学院生、ならびに野生アジアゾウの捕獲とGPS首輪装着の必要性等について確認した。また、研究協力者の大学院生（ネパールからの留学生2名：Rajan PaudelとArjun Pandit）により、チトワン国立公園における野生動物（ナマケグマ）の生態学的研究ならびに野生アジアゾウからの結核菌の分離および遺伝子型別の試験的実験を進めることができた。具体的には、チトワン国立公園におけるナマケグマの分布状況を食物資源との関係で解析した。また、BCGに使われる結核菌を使って家畜の糞から効率的に結核菌DNAを検出する方法論を検討した。さらに、研究協力者であるDr. Amir Sadaulaが、チトワン国立公園において飼育下アジアゾウから血液および糞のサンプリングを行った。最後に、令和4年度にはネパールへの渡航が可能になると予想され、近い将来アジアゾウに装着するGPS首輪の入手について取扱業者と打合せを行った。
Japan Society for the Promotion of Science, Fund for the Promotion of Joint International Research (Fostering Joint International Research (B)), Hokkaido University, 21KK0120 - Tick-borne diseases in brown bears and sika deer as hosts - Which determines the prevalence, host or vector?
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2021 - 31 Mar. 2024
坪田 敏男, 佐鹿 万里子, 下鶴 倫人, 中尾 亮, MOHAMED MOUSTAFA
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 21H02350 - Hibernation-induced bioactive molecules that contribute resistance to skeletal muscle atrophy
Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)
30 Jul. 2020 - 31 Mar. 2023
宮崎 充功, 坪田 敏男, 下鶴 倫人
【本研究成果のポイント】●冬眠期において採取したツキノワグマ血清と共にヒト筋肉細胞を培養すると、筋肉細胞の総タンパク質量を増加させることを明らかにした。●この筋肉細胞の総タンパク質量の増加は、冬眠期クマ血清の添加が筋タンパク質分解系を抑制することで達成される可能性を示した。●これらの成果は、長期間の不活動・栄養不良を経験し、それでもなお筋肉が衰えないという冬眠動物の特徴を説明するものであり、将来的にはヒトの寝たきり防止や効果的なリハビリテーション手法の開発につながることが期待される。
【研究成果の概要】本研究では、実験的に採取したツキノワグマ血清をヒト骨格筋培養細胞に添加するというin vitroの解析系を用いた検討を行ったところ、冬眠期クマ血清の添加により、骨格筋細胞における総タンパク質量が増加することを確認しました。また冬眠期クマ血清の添加は、タンパク質合成系の制御系であるAkt/mTOR系の制御に関与する可能性があること、またタンパク質分解系因子の一つであるMuRF1の発現量を転写因子FOXO3aの制御系を介して調節することなどを明らかにした。
【今後の研究の展開】冬眠動物は、生命維持のために一定程度のエネルギー代謝を維持しながら長期間の不活動・栄養不良を経験し、それでもなお筋肉がほとんど衰えないという、不思議な形質を備えている。本研究により、冬眠期のクマ血清に存在する「何らかの因子」がヒト骨格筋培養細胞のタンパク質代謝を制御し、筋肉量維持に貢献する可能性が示された。しかしながら、この「何らかの因子」の特定には現在も至っていない。この因子の特定を含め、冬眠動物が有する「使わなくても衰えない筋肉」という未解明の仕組みを明らかにすることで、最終的にはヒトの寝たきり防止や効果的なリハビリテーション手法の開発などが期待される。
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Health Sciences University of Hokkaido, 20K21769 - How does black bears spend their spring and summer - individual based ecological and physiological studies -
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2019 - 31 Mar. 2022
Yamazaki Koji
From spring to summer can be critical season for Japanese black bears, because of the body fat reserve which obtained in last autumn has been decreasing. Hence, the bears should ideally decline the activity level, and should minimize their energy expenditure during this period. We determine how the bears in different social status (e.g., sex, age, cub existence) respond to this situation using modern study equipment and methods. In the result, most of the bears, female with cub, adult males in heat, sub-adult male, were not able to decline the activity level. This behavioral character may cause the bear intrusion to human residential area before autumn.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tokyo University of Agriculture, 19H03002 - Thermo-regulation of hibernation in Japanese black bears - shivering or non-shivering? -
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2017 - 31 Mar. 2020
TSUBOTA TOSHIO
Aiming to elucidate the thermoregulatory mechanism in the Japanese black bear during hibernation, we conducted a study focusing on the non-shivering thermogenesis using body fat. A data logger for measuring body temperature and heart rate was embedded in the breast area of black bears in captivity (Ani Bear Park, Kitaakita City), and the body temperature and heart rate before and during hibernation period were monitored. As a result, soon after the black bears were moved to individual rooms in late November, their body temperature and heart rate decreased immediately following feeding was stopped, resulting in hibernation. After that, changes in body temperature and heart rate were observed differently in males and females, suggesting that the regulation mechanisms of body temperature and heart rate differ depending on the hibernation phase and/or reproductive process, especially in female bears. The presence of brown fat, which is used for non-shivering thermogenesis, was not found.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, 17H03936 - When do Japanese black bears store the body fat and how do they utilize it? - its behavioral ecology-
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2016 - 31 Mar. 2019
YAMAZAKI KOJI
Behavioral ecology of Japanese black bears in autumn is becoming clear, but it is not well documented from spring to summer. For this understanding, we applied three new study devices, implantable small sized heart rate logger, non-invasive body weighing system, and video-cam system with the collar. From the logger and weighing system, the weight and heart rate have clearly declined during the summer that is quite different to same genus of a bear (i.e., brown bear). Challenge to evaluate feeding quantities of bears using video-cam was not sufficient, because of the lens was frequently obstructed by the bear body than our expectation. However, we found possible solutions to fix this problem.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Tokyo University of Agriculture, 16H04939 - Mechanism of reproductive physiology under the condition of fasting and low metabolism - Hibernating bears as a model -
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
01 Apr. 2014 - 31 Mar. 2017
Tsubota Toshio
Heart rate (HR) and subcutaneous body temperature (BT) were being monitored by using data loggers (DST milli-HRT, Star:Oddi) for the measurement of HR and BT, which were implanted at the breast region, for about 6 months during winter season including pre-hibernation, hibernation and post-hibernation periods. In January, pregnancy diagnosis was done by using ultrasonography for these 5 bears. Notable findings were relationships between HR and BT in pregnant bears: both HR and BT during pre-hibernation period (delayed implantation period) changed with about 24 hours cycle, BT maintained relatively high and HR exhibited some spike during hibernation period (fetal development period) and both synchronized fluctuation with multi-day cycles during post-hibernation period (natal development period).
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 26450455 - Regulation of protein metabolism and muscle mass in hibernating bears: an attractive model of muscle atrophy resistance.
Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
01 Apr. 2014 - 31 Mar. 2017
MIYAZAKI Mitsunori, TSUBOTA TOSHIO, SHIMOZURU MICHITO
Hibernating mammals including bears experience prolonged periods of torpor and starvation during winter survival for up to 5-6 months. Though physical inactivity and malnutrition generally lead to profound loss of muscle mass and metabolic dysfunction in human, hibernating bears show limited muscle atrophy and can successfully maintain locomotive function following hibernation. In this study, we identified that protein synthesis rate and oxidative metabolism would be enhanced in skeletal muscle of hibernating bear (Japanese black bear) through modulating intracellular signal transduction (up-regulation of mTOR-dependent signaling and down-regulation of myostatin), which then lead to limited loss of muscle mass and maintenance of physical performance.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Health Sciences University of Hokkaido, 26560369 - Defence mechanism against environmental chemicals in livestock animals
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A)
01 Apr. 2012 - 31 Mar. 2016
ISHIZUKA MAYUMI, IKENAKA Yoshinori, TSUBOTA Toshio, KONNAI Satoru
In livestock animals, we identified the enzymatic characters of cytochrome P450 as typical phase I enzyme for xenobiotics. We also analyzed glucronyltrasnferase and sulfotransferase dependent metabolites in urine samples from mammalians including livestock animals, to elucidate the ability of xenobiotic conjugating detoxification. In field surveillance at Asia and African countries, heavy metals are major accumulated environmental pollutants in cattle, and the accumulating pattern is unique in ruminants. In case of poultry species, we clarify the expressed cytochrome P450 and phase II enzymes in liver using transcriptome analyses method and in silico analyses, and we compared the structure of xenobiotic metabolizing enzymes in poultry species to those of mammals.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (A), Hokkaido University, 24248056 - How do Japanese black bears stand during spring to summer? - A study on their behavioral ecology-
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2012 - 31 Mar. 2015
YAMAZAKI Koji, TSUBOTA Toshio, KOIKE Shinsuke, SHIMIZU Keiko, MAZAKI Takashi, KORI Mari, KOZAKAI Chinatsu, NAKAJIMA Ami, NEMOTO Yui
Most of the behavioral studies on Japanese black bears have been done during autumn at their hyperphagia period. In this study, we have tried to understand the bear behavioral ecology from spring to summer just after their hibernation time, using some newly developed equipment which will able to measure bear physiological status. In the results, we confirmed that the activity level, deep body temperature, and heart rate were being declined in summer. In the spring, bears could feed on new leaves which contained low fibers and high protein in short period, but there were very limited food resources in summer. Therefore, the bears went into like a walking hibernation status in summer, and seemed to be avoided energy losses. Our study can be useful for understanding bear intrusion around human habitation in summer which was not possible to be explained in terms of acorn production level in autumn.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Ibaraki Nature Museum, 24380088 - Understanding an attractive-sink effect on brown bear population and implications for damage management
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)
01 Apr. 2011 - 31 Mar. 2015
SATO Yoshikazu, TAKADA Mayura, SONOHARA Waka, TSUBOTA Toshio, MANO Tsutomu
Human-brown bear conflicts and the number of nuisance kills of bears are increasing in Hokkaido. We test a hypothesis that the conflicts is caused by an attractive-sink habitat near human settlements in eastern Hokkaido. We confirmed dispersal movement from population core to periphery. High mortality of bears as nuisance control using box trap and relatively well body condition of killed bear were confirmed in the peripheral habitat near crop fields. Peripheral habitat as an attractive and high mortality risk had high priority of management. We developed simple sustainable monitoring system using rubbing trap and camera trap for bear population trends throughout the population distribution.
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), 23380089 - Gut microbiota and gut mucosal barrier in hibernating animals
Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research
2011 - 2012
SONOYAMA Kei, TSUBOTA Toshio, TAKIGUCHI Mitsuyoshi
This study investigated the control of gut microbiota and gut mucosal barrier in hibernating animals. In hibernating Syrian hamsters, we observed higher concentrations of secretory antibodies in the small intestinal contents, suggesting its contribution to protection against infection. Indeed, no bacteria were observed in the mesenteric lymph node of hibernating hamsters. Analysis of lymphocyte profiles in the immune tissues indicated that ability to protect against infection and to regulate immune function may be maintained in the gut of hibernating hamsters. Furthermore, we found that cell renewal of intestinal epithelium is markedly retarded in hibernating hamsters.
Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Exploratory Research, Hokkaido University, 23659119 - Why do not obese bears suffer fatty liver?-Study on mechanism for accumulation of body fat during pre-hibernation period
Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)
2009 - 2011
TSUBOTA Toshio, SHIMOZU Rumichito
This study was conducted in Ani Mataginosato Bear Park, Kitaakita-shi, Akita Prefecture in order to know why obese bears do not suffer fatty liver even though they get 30-40% fat of body weight and to investigate a feature mechanism for accumulation of body fat. Under anesthetized condition, measurements of blood concentrations of carbohydrate and fat, intravenous glucose tolerance tests and adipose tissue biopsies were performed for this study. As results, it is concluded that increase of body fat accumulation during pre-hibernation period is controlled by physiological and metabolic mechanism as well as hyperphagia in Japanese black bears
Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, Principal investigator, Competitive research funding, 21580355 - Survey for lethal zoonoses and potential emerging and re-emerging infectious diseases in Africa
Grants-in-Aid for Scientific Research(基盤研究(A))
2005 - 2007
源 宣之, Hideto FUKUSHI, 福士 秀人, 杉本 千尋, 柵木 利昭, 坪田 敏男, 安田 準, 伊藤 直人, 淺野 玄
Emerging infectious diseases including SARS and avian influenza virus infection triggered the social problems in these years. Sources of these pathogens have been usually unknown, although the involvement of wild animals has been indicated. Furthermore, environmental destruction might be one of the cause of emerging infectious diseases.In this project, we planned to investigate the current situation of zoonoses and other infectious diseases in Africa where many emerging diseases have appeared almost every year in order to evaluate the environment changes and occurrences of the diseases. Add...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(A), 岐阜大学, Coinvestigator not use grants, Competitive research funding, 17255010 - Monitoring of reproductive cycle and clinic application of artificial breeding in endangered wildlife
Grants-in-Aid for Scientific Research(基盤研究(B))
2003 - 2006
Toshio TSUBOTA, 村瀬 哲磨
The purposes of this study were to monitor reproductive cycles by measuring sex steroid hormone concentrations non- invasively using molecular biology technique and to apply artificial breeding methods clinically under captive conditions in order to recover their populations in endangered wildlife. The following studies were conducted for 4 years in Tsushima wild cats and Japanese black bears.1. Measurement of fecal sex steroid hormone concentrations in Tsushima wild cats and Japanese black bears1) The method of measurement for fecal estradiol and progesterone concentrations using TR-FIA ki...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 岐阜大学, Principal investigator, Competitive research funding, 15380215 - 野生動物の救護に関する研究
2003
Competitive research funding - Wildlife rescue
2003
Competitive research funding - Investigation of reproduction and lactation strategies, ecological features and body pollutants of marine mammals in Arctic area
Grants-in-Aid for Scientific Research(基盤研究(B))
2001 - 2002
Yutaka FUKUI, 佐々木 基樹, 手塚 雅文, 浦島 匡, 坪田 敏男, 中村 正
Project reports: Fukui, Tsubota, Urashima, Tetsuka and Sasaki visited Zoological Museum of Oslo University, Norwegian Polar Institute, Svalbard University and Tromso University, and discussed with the scientists there on the pollutants in wild seals and bears, reproduction strategies of whales and bears as well as on lactation strategies of many mammalian species. Sasaki anatomized polar foxes and polar bears in Oslo University, and Tetsuka searched PCB pollution in polar bears and Arctic seals. Dr. O. Oftedal of Smithonian Institute had a lecture on "the origin and early evolution of lacta...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(B), 帯広畜産大学, Coinvestigator not use grants, Competitive research funding, 13575026 - 内分泌撹乱物質による野生動物の生殖異常の解明とバイオマーカーの開発
科学研究費補助金(特定領域研究(A))
2001 - 2001
坪田 敏男, 村瀬 哲磨
これまでに内分泌撹乱化学物質(EDs)が猛禽類に何らかの影響を与えているとする報告が数多くみられる。PCB類はハクトウワシにおいて生殖低下と関連付けられ、DDEはハヤブサやチョウゲンボウにおいて卵殻薄化との関連が示唆されている。わが国でも猛禽類の個体数減少及び繁殖状況の悪化が報じられている。その主たる要因は生息環境の悪化にあると思われるが、EDsも何らかの影響を与えていると推測されている。そこで本研究では、猛禽類において影響が大きいと考えられるダイオキシン類、PCB類およびDDT類の蓄積濃度とその影響を調べた。また、EDsの繁殖学的影響を明らかにするにあたり、猛禽類の繁殖生理解明の端緒としてトビの精巣の形態学的観察を行った。その結果、ダイオキシン類とP, P'-DDEに関して、何らかの影響が及んでいる可能性を否定できない蓄積が多くの猛禽類に認められた。繁殖期成鳥の検体が少なく、配偶子形成に関して十分な情報を得られなかったが、性腺に組織学的異常は認められず、これらの物質が発生学的影響を与えている可能性は低いと思われた。ダイオキシン類の蓄積傾向は種や生息地による食性の違いを反映していることが示唆され、今後食性を把握することにより猛禽類が地域の汚染状況のモニター生物として有用になり得ることが考えられた。しかし、影響や蓄積傾向を明らかにするには、食性や薬物代謝能、対象物質に対する感受...
文部科学省, 特定領域研究(A), 岐阜大学, Principal investigator, Competitive research funding, 13027234 - TRANSMISSIBLE DISEASES BETWEEN DOMESTIC AND WILD ANIMALS IN AFRICA
Grants-in-Aid for Scientific Research(基盤研究(A))
1999 - 2001
Jun YASUDA, 杉本 千尋, 小沼 操, 坪田 敏男, 稲垣 匡, 福士 秀人, 吉田 光敏
The prevalence of the BHV 1 antigens in cattle was 23.28 % while the mean prevalence of the BHV 1 antibodies was 48.28 %. The prevalence of the Rabies in Zambia was 3-28.8 %, especially in dogs and cattle was 75 % and 13 %, respectively. As the nucleotide sequences of dogs showed 93-99 % homology to wild beasts in Zambia, it was concluded that wild beasts were infected Rabies from dogs. The liver flukes obtained from cattle and Kafue lechwe were identified as Fasciola gigantica with normal spermatogenesis ability. The flukes from cattle showed three different genotypes (A, B and C), but tho...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(A), 北海道大学->岩手大学, Coinvestigator not use grants, Competitive research funding, 11691165 - Mechanism of Reproduction Disorder Caused by Endocrine Disruptors in Wild Animals
Grants-in-Aid for Scientific Research(基盤研究(C))
1999 - 2000
Toshio TSUBOTA, 村瀬 哲磨, 喜多 功
1) Detection of Reproductive Disorder Caused by Endocrine Disruptors in Wild AnimalsOrgan samples were obtained from dead bodies of wild raccoon dogs, bears, mice and raptors. Dead bodies from captive fur seals, sea lions and dolphins were also used for the samples. Accumulated concentrations of endocrine disruptors (PCB, HCH, DDT and its congeners, butyltins and agricultural chemicals) were measured using the liver and adipose tissue of the samples. Histological specimens of the reproductive tracts were employed for the pathological examination. A case of testicular cancer from a raccoon d...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(C), 岐阜大学, Principal investigator, Competitive research funding, 11839008 - Continuing monitaring and manegement of natural environment on wildlife pathobiology and ecology.
Grants-in-Aid for Scientific Research(基盤研究(A))
1998 - 2000
Toshiaki MASEGI, 坪田 敏男, 工藤 忠明, 源 宣之, 福士 秀人, 鈴木 義孝
1. To clarify the infectivity of parapox virus re-emerging in Japanese serow in mountains was inoculated to sheep. As a result, parapox virus was proved to spread from serow to sheep easily. This study warns the role of serow as a reservoir in parapox virus infection.2. GHV-1 is a new type emerging equine herpesvirus isolated from a mass outbreak of encephalitis in gazelles. In this study, GHV-1 was designated as EHV-9 based on virological and pathological studies. EHV-9 induced experimentally encephalitis in wide variety of animals including horses, goats, cattle, pigs, dogs, hamsters, mic...
Ministry of Education, Culture, Sports, Science and Technology, 基盤研究(A), 岐阜大学, Coinvestigator not use grants, Competitive research funding, 10306020 - 精巣における性ステロイドホルモンを介した細胞間相互作用に関する研究
科学研究費補助金(奨励研究(A))
1996 - 1996
坪田 敏男
本研究の目的は、各種雄動物における精巣でのステロイド産生能を検討することであった。そこで、イヌとツキノワグマの精巣を研究材料として、免疫組織化学および内分泌学的にステロイド産生能を検討した。方法は、イヌおよびツキノワグマの精巣を外科手術的に採取し、10%ホルマリン液で固定した。ツキノワグマについては各季節に採材を行なった。固定された材料は、常法にしたがってパラフィン切片とした。免疫染色は、キットを用いてABC法で行なった。使用した抗体は、4種類のステロイド合成酵素、P450scc、3βHSD、P450c17およびP450aromに対する抗血清であった。さらに、ツキノワグマについては血液を採取して、血液中のステロイド濃度をラジオイムノアッセイによって測定した。その結果、イヌでは、ライディッヒ細胞がアンドロジェン産生能を有し、また、精母細胞および精子細胞がエストロジェン産生能を有していた。ツキノワグマでは、交尾期にはやはりライディッヒ細胞がアンドロジェン産生能を有していたが、他の季節(非交尾期)でもP450sccおよびP450c17の染色性は変化しなかった。一方3βHSDについては、交尾期に比べて非交尾期に陽性細胞が顕著に減少した。また、交尾期には精子細胞がエストロジェン産生能を有していた。血中テストロン濃度は交尾期に高値を示し、非交尾期に底値を示した。
文部科学省, 奨励研究(A), 岐阜大学, Principal investigator, Competitive research funding, 08760297 - 各種雌動物の卵巣および胎盤におけるステロイド産生能について
科学研究費補助金(奨励研究(A))
1995 - 1995
坪田 敏男
本研究の目的は、各種雌動物における卵巣および胎盤でのステロイド産生能を検討することであった。そこで、ネコとツキノワグマの卵巣および胎盤を研究材料として免疫組織化学および内分泌学的にステロイド産生能の検討を行った。方法は、妊娠中のネコおよび妊娠していたと思われるツキノワグマの卵巣および胎盤を採集し、10%ホリマリン液で固定した。ネコについては生体より外科手術的に採取した。固定された材料は常法にしたがってパラフィン切片とした。免疫染色は、キットを用いてABC法で行った。使用した抗体は、4種類のステロイド合成酵素、P450scc、3βHSD、P450c17およびP450aromに対する抗血清であった。さらに、ツキノワグマについては妊娠雌より血液を採集して、血清中のステロイド濃度をラジオイムノアッセイによって測定した。その結果ネコでは、1)妊娠期のプロジェステロン産生母地は黄体から胎盤に移るが、妊娠後半期にも黄体はプレグネノロンの産生能を有する 2)胎盤の栄養膜合胞体層はエストロジェン(妊娠期間全体)およびプロジェステロン(妊娠後半期)の産生能を有し、加えて妊娠末期には脱落膜細胞がエストロジェンおよびプレグネノロンの産生能を有することが推察された。ツキノワグマでは、1)着床遅延初期には黄体が主要なプロジェステロン産生母地であるが、少量ながらエストロジェンも産生されている 2)黄体での...
文部科学省, 奨励研究(A), 岐阜大学, Principal investigator, Competitive research funding, 07760299 - 哺乳動物の季節繁殖性に関する研究
Competitive research funding - 内分泌かく乱化学物資による野生動物への影響
Competitive research funding - 野生動物の繁殖生理に関する研究
Competitive research funding - Seasonality on reproducction of mammals
Competitive research funding - Affects of endocrine disruptours on wildlife
Competitive research funding - Reproductive physiology of bears
Competitive research funding
