研究者データベース

下鶴 倫人(シモヅル ミチト)
獣医学研究院 獣医学部門 環境獣医科学分野
准教授

基本情報

所属

  • 獣医学研究院 獣医学部門 環境獣医科学分野

職名

  • 准教授

学位

  • 博士(獣医学)(東京大学)

ホームページURL

J-Global ID

研究キーワード

  • 動物行動学   生物多様性   生態系保全   野生動物   ヒグマ   ツキノワグマ   冬眠   クマ   hibernation   

研究分野

  • ライフサイエンス / 動物生産科学
  • ライフサイエンス / 動物生産科学
  • ライフサイエンス / 獣医学
  • ライフサイエンス / 獣医学
  • ライフサイエンス / 獣医学

職歴

  • 2017年04月 - 現在 北海道大学 獣医学研究院 准教授
  • 2013年05月 - 2017年03月 北海道大学 獣医学研究科 准教授
  • 2008年04月 - 2013年05月 北海道大学 (連合)獣医学研究科 助教

所属学協会

  • International Bear Association   日本獣医学会   日本野生動物医学会   日本哺乳類学会   日本生態学会   

研究活動情報

論文

  • Minami W Okuyama, Michito Shimozuru, Mariko Nakai, Emi Yamaguchi, Kei Fujii, Ken-Ichiro Shimada, Tohru Ikeda, Toshio Tsubota
    Scientific reports 10 1 8108 - 8108 2020年05月15日 [査読有り][通常論文]
     
    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 98 175 - 185 2020年 [査読有り][通常論文]
  • Junko Takei, Shinji Yamada, Satoru Konnai, Tsuyoshi Ishinazaka, Michito Shimozuru, Mika K Kaneko, Yukinari Kato
    Monoclonal antibodies in immunodiagnosis and immunotherapy 38 6 282 - 284 2019年12月 [査読有り][通常論文]
     
    Podoplanin (PDPN)/T1alpha is utilized as a specific marker of lymphatic endothelial cells or type I alveolar cells of lung. Therefore, sensitive and specific monoclonal antibodies (mAbs) detecting PDPN are necessary for immunohistochemical analyses, especially using formalin-fixed paraffin-embedded tissues. Recently, we developed an anti-bear PDPN (bPDPN) mAb, PMab-247, which is useful for immunohistochemical analyses to detect both lymphatic endothelial cells and type I alveolar cells of lung. However, it is difficult to distinguish lymphatic endothelial cells from type I alveolar cells in the bear lung. In this study, we showed that a novel anti-bPDPN mAb, PMab-241 stained only lymphatic endothelial cells, not type I alveolar cells of the lung in immunohistochemical analyses. These findings suggest that PMab-241 could be useful for staining lymphatic endothelial cells specifically in the bear lung tissues.
  • Aya Osaki, Mariko Sashika, Go Abe, Kohei Shinjo, Ayako Fujimoto, Mariko Nakai, Michito Shimozuru, Toshio Tsubota
    BMC ecology 19 1 35 - 35 2019年09月11日 [査読有り][通常論文]
     
    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.
  • 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 2019年07月 [査読有り][通常論文]
     
    Natal dispersal likely plays an important role in avoiding inbreeding among large carnivores. We tested the hypothesis that male-biased dispersal reduces close inbreeding by limiting the spatial overlap of opposite-sex pairs of close relatives in brown bears (Ursus arctos) in the Shiretoko Peninsula, Hokkaido, Japan. We genotyped 837 individuals collected in 1998-2017 at 21 microsatellite loci and performed parentage analysis. To calculate natal dispersal distance, we considered the site where the mother was identified as the birthplace of her offspring, and the site where the offspring were identified as their dispersed place. As predicted, we found that dispersal distances were significantly greater for males (12.4 km +/- 1.0) than for females (7.7 km +/- 0.9), and those for males increased from 3 years old, indicating that males begin to disperse around the time sexual maturation begins. Relatedness decreased with distance among pairs of females, and the mean relatedness was significantly higher between pairs of females than between pairs of males or between female-male pairs within 3 km. Closely related female-male pairs rarely (5-6%) resided in close proximity (< 3 km), compared with pairs of closely related females. Our study revealed that the potential for close inbreeding was low in Hokkaido brown bears because males are effective dispersers.
  • 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 2019年05月 [査読有り][通常論文]
  • 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 2019年05月 [査読有り][通常論文]
  • Mitsunori Miyazaki, Michito Shimozuru, Toshio Tsubota
    PloS one 14 4 e0215489  2019年 [査読有り][通常論文]
     
    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.
  • Kadariya, R, Shimozuru, M, Maldonado, J.E, Moustafa, M.A.M, Sashika, M, Tsubota, T
    PloS one in press 12 e0207662  2018年12月 [査読有り][通常論文]
  • 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 2018年12月 [査読有り][通常論文]
  • Jun Moriwaki, Ryosuke Omori, Michito Shimozuru, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota
    Japanese Journal of Veterinary Research 66 2 71 - 81 2018年05月01日 [査読有り][通常論文]
     
    Chest girth and body mass of 3,576 brown bears (Ursus arctos yesoensis) harvested for conflict management in Hokkaido, Japan during 1991-2012 were used to establish methods to assess body condition and to compare the body condition of bears by sex, month, year, and reproductive status. The body mass was estimated based on the chest girth in cases with no measurements of the bear body mass. Using the measured and estimated body mass, a growth curve by age was demonstrated to ascertain the mean asymptotical body mass (245 kg for males, 114 kg for females) and ages at 95% asymptotic body mass (14.2 years for males, 7.1 years for females). The body condition value of bears was evaluated as body mass difference (kg) between the individual body mass and the standard body mass as estimated from the growth curve. Body condition value changed seasonally with a low in summer and the highest in the autumnal hyperphagic period. Female body condition value was higher than the males during September. Fluctuation in annual body condition value was found for females however, there was no difference between solitary adult females and females with offspring (cubs, yearlings, or offspring of unknown age). No significant fluctuation was found for males. Our body condition evaluation method using chest girth and body mass of brown bears is useful to elucidate different trends across sex, year, and season.
  • Jumpei Tomiyasu, Yojiro Yanagawa, Yoshikazu Sato, Michito Shimozuru, Masashi Nagano, Motoki Sasaki, Hideyuki Sakamoto, Naoya Matsumoto, Kohei Kobayashi, Mitsunori Kayano, Shingo Haneda, Motozumi Matsui
    Canadian Journal of Zoology 96 3 205 - 211 2018年 [査読有り][通常論文]
     
    Adult male brown bears (Ursus arctos Linnaeus, 1758) display tree-marking behavior to chemically signal their dominance throughout the nondenning period, and this behavior peaks during the breeding season. Within the scent-marking sequence, back rub is a core marking posture. The present study investigated (i) seasonal changes in sebaceous glands in the back skin of brown bears and (ii) the relationship between those changes and testosterone levels. Back skin tissue samples and blood were collected from captive adult intact and castrated males during prebreeding, transitional, breeding, and postbreeding seasons, which were concurrent with back skin observations. In intact males, during the transitional and breeding seasons, an oily secretion from the back skin was observed along with enlarged sebaceous glands. The plasma testosterone concentrations during the transitional and breeding seasons were increased compared with the pre- and post-breeding seasons. Secretions and enlarged sebaceous glands were not found in castrated males, and the plasma testosterone concentrations remained at baseline levels. Oily secretions of the back skin glands that appear more abundant during the breeding season are rubbed against trees. Changes in size and volume of sebaceous glands, and thus their secreting capacity, are likely testosterone-regulated.
  • Mohamed Abdallah Mohamed Moustafa, Michito Shimozuru, Wessam Mohamed, Kyle Rueben Taylor, Ryo Nakao, Mariko Sashika, Toshio Tsubota
    PARASITOLOGY RESEARCH 116 8 2321 - 2325 2017年08月 [査読有り][通常論文]
     
    Sarcocystis and Hepatozoon species are protozoan parasites that are frequently detected in domestic and wild animals. Rodents are considered common intermediate and paratenic hosts for several Sarcocystis and Hepatozoon species. Here, blood DNA samples from a total of six rodents, including one Myodes rutilus, one Myodes rufocanus, and four Apodemus speciosus, collected from Hokkaido, Japan, were shown by conventional PCR of the 18S ribosomal RNA (rRNA) gene to contain Sarcocystis and Hepatozoon DNA. Sequencing of the DNA detected one Sarcocystis sp. in the M. rufocanus sample and two different Hepatozoon spp. in the M. rutilus and A. speciosus samples. Phylogenetic analysis showed that the detected Sarcocystis sp. sequence grouped with GenBank Sarcocystis sequences from rodents, snakes, and raccoons from Japan and China. The 18S rRNA partial gene sequences of both detected Hepatozoon spp. clustered with GenBank Hepatozoon sequences from snakes, geckos and voles in Europe, Africa, and Asia. This study provides evidence that wild rodents have a role in the maintenance of Sarcocystis and Hepatozoon species on the island of Hokkaido.
  • 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 2017年04月 [査読有り][通常論文]
     
    servation and management of wildlife. In this study, we investigated the demographic parameters, including age of primiparity, litter size, inter-birth interval, reproductive rate, and cub survival rate, of Hokkaido brown bears (Ursus arctos yesoensis) in the Rusha area on the Shiretoko Peninsula, Hokkaido, Japan, based on a long-term, individual-based monitoring survey. A total of 15 philopatric females were observed nearly every year from 2006 to 2016, and these observations were used to estimate reproductive parameters. The mean age of primiparity was 5.3 +/- 0.2 (SE) years (n = 7, 95% CI = 5.0-5.6). We observed 81 cubs in 46 litters from 15 bears. Litter size ranged from one to three cubs, and averaged 1.76 +/- 0.08 (SE) cubs/litter (95% CI = 1.61-1.91). Inter-birth intervals ranged from 1 to 4 years, and the mean value was estimated as 2.43 (95% CI = 2.16-2.76) and 2.53 (95% CI = 2.26-2.85) years in all litters and in litters that survived at least their first year, respectively. The reproductive rate was estimated from 0.70 to 0.76 young born/year/reproductive adult female, depending on the method of calculation. The cub survival rate between 0.5 and 1.5 years ranged from 60 to 73%. Most cub disappearances occurred in July and August, suggesting that cub mortality is mainly due to poor nutrition in the summer. All reproductive parameters observed in the Rusha area on the Shiretoko Peninsula fell within the range reported in Europe and North America, and were among the lowest or shortest age of primiparity, litter size, and inter-birth intervals, and ranked at a high level for reproductive rate.
  • 知床半島先端部地区におけるヒグマ個体群の保護管理、および、羅臼町住民生活圏へ与える影響に関する研究
    下鶴倫人, 山中正実
    知床博物館研究報告特別号 2 95 - 120 2017年 [査読有り][招待有り]
  • 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年 [査読有り][通常論文]
     
    Babesia and Theileria species are tick-borne protozoan parasites that have a veterinary and zoonotic importance. In order to investigate the prevalence and genetic diversity of these parasites, a total of 269 sika deer blood DNA samples collected from Hokkaido, Japan, were examined for Babesia and Theileria species by touch-down PCR targeting the 18S rRNA gene. Reverse line blot (RLB) hybridization was then used to detect 12 piroplasm species. The results revealed that 95.5% (257/269), 94.1% (253/269), 14.1% (38/269), 87.7% (236/269) and 11.5% (31/269) of the examined PCR products hybridized with the probes which were designed to detect all Babesia and Theileria spp., all Theileria spp., all Babesia spp., Theileria sp. Thrivae and Babesia divergens-like, respectively. The 18S rRNA gene partial sequences were divided into Theileria sp. Thrivae, T. capreoli, B. divergens-like and an undescribed Babesia species. This study showed the first detection of the undescribed Babesia sp. from Japan. Therefore, more studies are required to understand the ecology of the newly detected tick-borne pathogens in Hokkaido.
  • 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 2016年11月 [査読有り][通常論文]
     
    We compared cortisol and thyroid hormone (T3 and T4) concentrations between tuberculosis (TB)-suspected (n=10) and healthy (n=10) elephants of Nepal. Whole blood was collected from captive elephants throughout Nepal, and TB testing was performed using the ElephantTB STAT-PAK (R) and DPP VetTB (R) serological assays that detect antibodies against Mycobacterium tuberculosis and M bovis in elephant serum. Cortisol, T3 and T4 were quantified by competitive enzyme immunoassays, and the results showed no significant differences in hormone concentrations between TB-suspect and healthy elephants. These preliminary data suggest neither adrenal nor thyroid function is altered by TB disease status. However, more elephants, including those positively diagnosed for TB by trunk wash cultures, need to be evaluated over time to confirm results.
  • 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 2016年07月 [査読有り][通常論文]
     
    We developed an interferon-gamma release assay (IGRA) specific for Asian elephants (Elephas maximus). Whole blood collected from forty captive Asian elephants was stimulated with three different mitogens i.e., phytohemagglutinin (PHA), pokweed mitogen (PWM) and phorbol myristate aceteate/ionomycin (PMA/I). A sandwich ELISA that was able to recognize the recombinant elephant interferon-gamma (rEIFN-gamma) as well as native interferon-gamma from the Asian elephants was performed using anti-elephant IFN-gamma rabbit polyclonal antibodies as capture antibodies and biotinylated anti-elephant IFN-gamma rabbit polyclonal antibodies as detection antibodies. PMA/I was the best mitogen to use as a positive control for an Asian elephant IGRA. The development of an Asian elephant-specific IGRA that detects native IFN-gamma in elephant whole blood provides promising results for its application as a potential diagnostic tool for diseases, such as tuberculosis (TB) in Asian elephants.
  • Michito Shimozuru, Akiko Nagashima, Jun Tanaka, Toshio Tsubota
    COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY 196 38 - 47 2016年06月 [査読有り][通常論文]
     
    Bears undergo annual cycles in body mass: rapid fattening in autumn (i.e., hyperphagia), and mass loss in winter (i.e., hibernation). To investigate how Japanese black bears (Ursus thibetanus japonicus) adapt to such extreme physiological conditions, we analyzed changes in the mRNA expression of energy metabolism-related genes in white adipose tissues and skeletal muscle throughout three physiological stages: normal activity (June), hyperphagia (November), and hibernation (March). During hyperphagia, quantitative real-time polymerase chain reaction analysis revealed the upregulation of de novo lipogenesis-related genes (e.g., fatty acid synthase and diacylglycerol O-acyltransferase 2) in white adipose tissue, although the bears had been maintained with a constant amount of food. In contrast, during the hibernation period, we observed a downregulation of genes involved in glycolysis (e.g., glucose transporter 4) and lipogenesis (e.g., acetyl-CoA carboxylase 1) and an upregulation of genes in fatty acid catabolism (e.g., carnitine palmitoyltransferase 1A) in both tissue types. In white adipose tissues, we observed upregulation of genes involved in glyceroneogenesis, including pyruvate carboxylase and phosphoenolpyruvate carboxykinase 1, suggesting that white adipose tissue plays a role in the recycling of circulating free fatty acids via re-esterification. In addition, the downregulation of genes involved in amino acid catabolism (e.g., alanine aminotransferase) and the TCA cycle (e.g., pyruvate carboxylase) indicated a role of skeletal muscle in muscle protein sparing and pyruvate recycling via the Cori cycle. These examples of coordinated transcriptional regulation would contribute to rapid mass gain during the pre-hibernation period and to energy preservation and efficient energy production during the hibernation period. (C) 2016 Elsevier Inc. All rights reserved.
  • 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年 [査読有り][通常論文]
     
    Many of the emerging infectious diseases originate in wildlife and many of them are caused by vector borne pathogens. In Japan, zoonotic tick-borne pathogens (TBPs) are frequently detected in both ticks and wildlife. Here, we studied the infection rates of potentially zoonotic species, including Anaplasma, Ehrlichia, Neoehrlichia and Babesia spp., in Hokkaido's most abundant small mammals as they relate to variable extrinsic factors that might affect the infection rates of these pathogens. A total of 412 small mammals including 64 Apodemus argenteus, 219 Apodemus speciosus, 78 Myodes rufocanus, 41 Myodes rutilus, 6 Myodes rex and 4 Sorex unguiculatus were collected from Furano and Shari sites in Hokkaido, Japan, in 2010 and 2011 and were examined by multiplex PCR for TBPs. A reverse line blot hybridization (RLB) was then developed for the specific detection of 13 potentially zoonotic TBPs. A total of 4 TBPs were detected: Anaplasma sp. AP-sd, Ehrlichia muris, Candidatus Neoehrlichia mikurensis and Babesia microti. The infection rates were 4.4% (18/412), 1.2% (5/412), 13.1% (54/412) and 17.2% (71/412), respectively. The infection rates of each of the detected TBPs were significantly correlated with host small mammal species. A total of 22 (two triple and 20 double) co-infection cases were detected (5.3%). The most frequent co-infection cases occurred between Candidatus N. mikurensis and B. microti 68.2% (15/22). Further studies are required to examine human exposure to these zoonotic TBPs in Hokkaido. (C) 2016 Elsevier GmbH. All rights reserved.
  • Jun Moriwaki, Michito Shimozuru, Hifumi Tsuruga, Tsutomu Mano, Toshio Tsubota
    URSUS 27 2 99 - 109 2016年 [査読有り][通常論文]
     
    The reproductive tracts of 130 adult female brown bears (Ursus arctos) in Hokkaido, Japan, euthanized during 2010-2013 for conflict management, were examined for the presence and number of corpora lutea (CL) in the ovary and placental scars (PS) in the uterine horns. We scored PS on a 0-5 scale based on morphological features including their rim and color. They were characterized as representing either current-year parturition, as determined by accompanying cubs, or previous year parturition, as determined by accompanying yearlings. In total, 128 females were divided into 3 reproductive categories: 44 females with current-year parturition, 39 with previous-year parturition, and 45 solitary females that had not given birth for >2 years. The estimated ovulation rate was 2.21 +/- 0.55 (mean +/- SD), the implantation rate was 1.91 +/- 0.74, and the litter size was 1.54 +/- 0.51. Implantation rates were lower than ovulation rates and changed annually during 2010-2013. Systematic observation of PS and CL allowed us to evaluate the reproductive history and parameters in Hokkaido brown bears and ascertain their annual variation.
  • Mohamed Abdallah Mohamed Moustafa, Kyunglee Lee, Kyle Taylor, Ryo Nakao, Mariko Sashika, Michito Shimozuru, Toshio Tsubota
    INFECTION GENETICS AND EVOLUTION 36 268 - 274 2015年12月 [査読有り][通常論文]
     
    A previously undescribed Anaplasma species (herein referred to as AP-sd) has been detected in sika deer, cattle and ticks in Japan. Despite being highly similar to some strains of A. phagocytophilum, AP-sd has never been detected in humans. Its ambiguous epidemiology and the lack of tools for its specific detection make it difficult to understand and interpret the prevalence of this Anaplasma species. We developed a method for specific detection, and examined AP-sd prevalence in Hokkaido wildlife. Our study included 250 sika deer (Cervus nippon yesoensis), 13 brown bears (Ursus arctos yesoensis) and 252 rodents including 138 (Apodemus speciosus), 45 (Apodemus argenteus), 42 (Myodes rufocanus) and 27 (Myodes rutilus) were collected from Hokkaido island, northern Japan, collected during 2010 to 2015. A 770 bp and 382 bp segment of the 16S rRNA and gltA genes, respectively, were amplified by nested PCR. Results were confirmed by cloning and sequencing of the positive PCR products. A reverse line blot hybridization (RLB) based on the 16S rRNA gene was then developed for the specific detection of AP-sd. The prevalence of AP-sd by nested PCR in sika deer was 51% (128/250). We detected this Anaplasma sp. for the first time in wild brown bears and rodents with a prevalence of 15% (2/13) and 2.4% (6/252), respectively. The sequencing results of the 16S rRNA and gltA gene amplicons were divergent from the selected A. phagocytophilum sequences in GenBank. Using a newly designed AP-sd specific probe for RLB has enabled us to specifically detect this Anaplasma species. Besides sika deer and cattle, wild brown bears and rodents were identified as potential reservoir hosts for AP-sd. This study provided a high throughput molecular method that specifically detects AP-sd, and which can be used to investigate its ecology and its potential as a threat to humans in Japan. (C) 2015 Elsevier B.V. All rights reserved.
  • 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 2014年05月 [査読有り][通常論文]
     
    Mycobacterium tuberculosis was cultured from the lung tissues of 3 captive elephants in Nepal that died with extensive lung lesions. Spoligotyping, TbD1 detection and multi-locus variable number of tandem repeat analysis (MLVA) results suggested 3 isolates belonged to a specific lineage of Indo-Oceanic clade, EAI5 SIT 138. One of the elephant isolates had a new synonymous single nucleotide polymorphism (SNP) T231C in the gyrA sequence, and the same SNP was also found in human isolates in Nepal. MLVA results and transfer history of the elephants suggested that 2 of them might be infected with M. tuberculosis from the same source. These findings indicated the source of M. tuberculosis infection of those elephants were local residents, presumably their handlers. Further investigation including detailed genotyping of elephant and human isolates is needed to clarify the infection route and eventually prevent the transmission of tuberculosis to susceptible hosts. (C) 2014 Elsevier Ltd. All rights reserved.
  • Minami W. Okuyama, Michito Shimozuru, Toshio Tsubota
    JOURNAL OF VETERINARY MEDICAL SCIENCE 76 5 773 - 775 2014年05月 [査読有り][通常論文]
     
    A genetic method for sex determination in raccoons was developed based on nucleotide differences of the zinc finger protein genes ZFX and ZFY. Four novel internal primers specific for ZFX or ZFY were designed. PCR amplification using two primer sets followed by agarose gel electrophoresis enabled sex determination. 141-bp and 447-bp bands were in both sex, and 346-bp band was specific only in male with primer set I. 345-bp and 447-bp bands were in both sex, and 141-bp band was specific only in male with primer set II, which could distinguish raccoon's electrophoresis pattern from three native carnivores in Hokkaido. This method will be useful for conservation genetics studies or biological analyses of raccoons.
  • Minami W. Okuyama, Michito Shimozuru, Yojiro Yanagawa, Toshio Tsubota
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 60 2 155 - 161 2014年04月 [査読有り][通常論文]
     
    The raccoon is a seasonal breeder with a mating season in the winter. In a previous study, adult male raccoons exhibited active spermatogenesis with high plasma testosterone concentrations, in the winter mating season. Maintenance of spermatogenesis generally requires high testosterone, which is produced by steroidogenic enzymes. However, even in the summer non-mating season, some males produce spermatozoa actively despite low plasma testosterone concentrations. To identify the factors that regulate testosterone production and contribute to differences in spermatogenetic activity in the summer non-mating season, morphological, histological and endocrinological changes in the testes of wild male raccoons should be known. In this study, to assess changes in the biosynthesis, metabolism and reactivity of testosterone, the localization and immunohistochemical staining intensity of four steroidogenic enzymes (P450scc, P450c17, 3 beta HSD, P450arom) and the androgen receptor (AR) were investigated using immunohistochemical methods. P450scc and P450c17 were detected in testicular tissue throughout the year. Seasonal changes in testosterone concentration were correlated with 3 beta HSD expression, suggesting that 3 beta HSD may be important in regulating the seasonality of testosterone production in raccoon testes. Immunostaining of P450arom and AR was detected in testicular tissues that exhibited active spermatogenesis in the summer, while staining was scarce in aspermatogenic testes. This suggests that spermatogenesis in the raccoon testis might be maintained by some mechanism that regulates P450arom expression in synthesizing estradiol and AR expression in controlling reactivity to testosterone.
  • Susumu Urakawa, Dai Mitsushima, Michito Shimozuru, Yasuo Sakuma, Yasuhiko Kondo
    PLOS ONE 9 2 2014年02月 [査読有り][通常論文]
     
    Early life events induce alterations in neural function in adulthood. Although rearing in an enriched environment (EE) has a great impact on behavioral development, the effects of enriched rearing on sociosexual behavior remain unclear. In this study, we investigated the effects of rearing in an EE on male copulatory behavior and its underlying neurobiological mechanisms in Wistar-Imamichi rats. Three-week-old, recently weaned rats were continuously subjected to a standard environment (SE) or an EE comprised of a large cage with several objects, such as toys, tunnels, ladders, and a running wheel. After 6 weeks, rats reared in an EE (EE rats) showed decreased sexual activity compared with rats reared in a SE (SE rats). This included a lower number of ejaculations and longer latencies in three consecutive copulatory tests. In addition, EE rats showed decreased emotional responsiveness and less locomotor behavior in an open field. In a runway test, on the other hand, sexual motivation toward receptive females in EE males was comparable to that of SE males. Furthermore, following exposure to a female, increases in serotonin levels in the nucleus accumbens and the striatum were significantly suppressed in EE males, whereas dopaminergic responses were similar between the groups. Female-exposure-induced increases in the levels of plasma corticosterone and testosterone were also suppressed in EE rats compared to SE rats. These data suggest that rearing in an EE decreases male copulatory behavior, and serotonin and hormonal regulating systems may regulate the differences in sociosexual interactions that result from distinct rearing environments.
  • 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年 [査読有り][通常論文]
     
    A relapsing fever Borrelia sp. similar to Borrelia lonestari (herein referred to as B. lonestari-like) was detected from wild sika deer (Cervus nippon yesoensis) and Haemaphysalis ticks in the eastern part of Hokkaido, Japan. The total prevalence of this Borrelia sp. in tested deer blood samples was 10.6% using conventional PCR and real-time PCR. The prevalence was significantly higher in deer fawns compared to adults (21.9% and 9.4%, respectively). Additionally, there was significant regional difference between our two sampling areas, Shiretoko and Shibetsu with 17% and 2.8% prevalence, respectively. Regional differences were also found in tick species collected from field and on deer. In the Shiretoko region, Haemaphysalis spp. were more abundant than Ixodes spp., while in Shibetsu, Ixodes spp. were more abundant. Using real-time PCR analysis, B. lonestari-like was detected from 2 out of 290 adult Haemaphysalis spp. ticks and 4 out of 76 pools of nymphs. This is the first report of a B. lonestari-like organism in Haemaphysalis spp. ticks, and the first phylogenetic analysis of this B. lonestari-like organism in Asia. Based on our results, Haemaphysalis spp. are the most likely candidates to act as a vector for B. lonestari-like; furthermore, regional variation of B. lonestari-like prevalence in sika deer may be dependent on the population distribution of these ticks. (C) 2014 Elsevier GmbH. All rights reserved.
  • 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 2013年08月 [査読有り][通常論文]
     
    The raccoon (Procyon lotor), indigenous to North America, has naturalized in Japan as an invasive alien species, having been introduced into the country in the 1970s. In Hokkaido, the northernmost island of Japan, feral raccoons have been increasing in number and spreading throughout the island. The age at the onset of puberty for raccoons is important for estimating individual lifetime reproductive success and population growth. The present study investigated the timing of and potential factors affecting the onset of puberty in male raccoons in Hokkaido. External characteristics and histology of testes were studied in 151 male feral raccoons and in 1 captive juvenile. For the majority of feral yearling raccoons, prepubertal development began in May, and spermatozoa production began in October prior to their second mating season. However, some larger juveniles attained puberty during the juvenile period. The captive juvenile, which was fed throughout the winter, attained puberty only 11 months after birth. These results suggest that if male raccoons can achieve enough body growth before the first mating season, puberty can be attained early. In both juveniles and yearlings, spermatozoa production was only observed after autumn. This timing coincided with the recrudescence of seasonally active spermatogenesis in adult males. Therefore, attaining puberty in male raccoons appears to require both adequate body nutrient development and several environmental factors that control seasonal testicular changes.
  • Michito Shimozuru, Ruriko Iibuchi, Takuro Yoshimoto, Akiko Nagashima, Jun Tanaka, Toshio Tsubota
    JOURNAL OF MAMMALOGY 94 3 618 - 627 2013年06月 [査読有り][通常論文]
     
    Bears from the family Ursidae are the only terrestrial mammals that go through gestation, parturition, and lactation during hibernation. This is the 1st study to examine the influence of reproductive status (i.e., nonpregnant, pseudopregnant, or pregnant) on body temperature and blood biochemical profiles in hibernating black bears. Pregnant bears appeared to have higher and more stable body temperatures (37-38 degrees C) than nonpregnant ones (34-36 degrees C) during pregnancy, which was followed by a rapid drop to levels comparable to those of nonpregnant individuals after parturition. In midpregnancy (i.e., January), pregnant bears had higher blood glucose and lower triglyceride concentrations than did nonpregnant ones, whereas blood concentrations of free fatty acids, glycerol, and ketone bodies did not differ significantly. Plasma urea, creatinine, and urea/creatinine levels were significantly lower in pregnant bears than in nonpregnant ones. Pseudopregnant bears showed similar changes in body temperature and blood profiles to pregnant ones, but blood glucose levels in January were significantly lower than those in pregnant bears. These results suggest that pregnant bears maintain homeothermic conditions and supply nutrients to the fetus by stimulating thermogenesis, gluconeogenesis, and urea recycling during hibernation. In addition, these physiological changes appear to be mainly caused by corpus luteum-derived factors (e.g., progesterone) but also were facilitated by placental factors.
  • Kyle R. Taylor, Ai Takano, Satoru Konnai, Michito Shimozuru, Hiroki Kawabata, Toshio Tsubota
    JOURNAL OF VETERINARY MEDICAL SCIENCE 75 6 785 - 790 2013年06月 [査読有り][通常論文]
     
    The ecologies of Lyme disease Borrelia spp. are very specific to location, as they are dependent upon the spirochete species and genotypes, the vectors and the host vertebrates present. In Hokkaido, Japan, where two human pathogenic, Lyme disease Borrelia spp. are present, and human cases are reported annually, the ecologies have been poorly studied. Our goal was to determine whether variation in borrelial infection rates among rodent species sharing an environment, is due to immunological or ecological differences. To this end, we examined the relationships between tick burden and borrelial infection, by including examination of agreement between nested PCR, as a test for infection, and serology, as a test for exposure. We collected 868 rodents, comprised of four species commonly found in Hokkaido, and tested for infection rates with Borrelia spp. using PCR for the borrelial flaB gene, seroprevalence of Borrelia afzelii and Borrelia garinii using ELISA, and attachment of ticks by direct counts. We noted a correlation between differential nymph and larval burdens and the borrelial infection rates found among the four rodent species. Furthermore, there was significant correlation between infection and seroprevalence of B. afzelii and B. garinii (P<0.01), between infection and Ixodes persulcatus nymph burden (P<0.01), and between seroprevalence and I. persulcatus nymph burden (P<0.01). The close agreement among rodent species seroprevalences with infection rates and tick burdens suggest the differences in infection rates of Borrelia spp. may largely be a direct consequence of differential exposure to vectors.
  • Kyle R. Taylor, Ai Takano, Satoru Konnai, Michito Shimozuru, Hiroki Kawabata, Toshio Tsubota
    VECTOR-BORNE AND ZOONOTIC DISEASES 13 2 92 - 97 2013年02月 [査読有り][通常論文]
     
    To clarify how Borrelia miyamotoi is maintained in the environment in Hokkaido, we examined Ixodes persulcatus for its prevalence among wild rodents and its tick vector by detecting a portion of the borrelial flaB gene in rodent urinary bladder and blood samples, and from whole ticks. We compared B. miyamotoi infection rates to Borrelia garinii and Borrelia afzelii, which are human Lyme disease pathogens also carried by wild rodents, and which are transmitted by the same vector tick. Whereas B. garinii and B. afzelii showed age dependence of infection rates among wild rodents (18.4% and 9.9% among adults and 6.0% and 3.4% among sub-adults, respectively) when looking at urinary bladder samples, B. miyamotoi infection rates were not age dependent for either blood (4.2% among adults, and 7.9% among sub-adults) or urinary bladder samples (1.0% among adults, and 1.7% among sub-adults). Moreover, while B. garinii and B. afzelii infection rates showed increases across months (June, July [p < 0.05] and August [p < 0.01] had higher rates than in May for adult rodents with B. garinii, and July and August had higher rates than in May [p < 0.01] for adult rodents with B. afzelii), B. miyamotoi infection rates did not show significant month dependence. These differences in month and age dependence led us to suspect that B. miyamotoi may not develop persistent infections in wild rodents, as B. garinii and B. afzelii are thought to. Furthermore, we examined the extent of rodent exposure to I. persulcatus nymphs and larvae throughout most of the tick's active season (May through September), and determined that B. miyamotoi infection rates in sub-adult rodents were correlated with larval burden (p < 0.01), suggesting that larvae may be very important in transmission of B. miyamotoi to wild rodents.
  • Takanori Kooriyama, Hideo Hasegawa, Michito Shimozuru, Toshio Tsubota, Toshisada Nishida, Takashi Iwaki
    PRIMATES 53 4 365 - 375 2012年10月 [査読有り][通常論文]
     
    Parasitological surveillance in primates has been performed using coprological observation and identification of specimens from chimpanzees (Pan troglodytes schweinfurthii) in Mahale Mountains National Park, Tanzania (Mahale). In this study, we conducted coprological surveillance to identify the fauna of parasite infection in five primate species in Mahale: red colobus (Procolobus badius tephrosceles), red-tailed monkeys (Cercopithecus ascanius schmidti), vervet monkeys (Cercopithecus aethiops pygerythrus), yellow baboons (Papio cynocephalus), and chimpanzees. Fecal samples were examined microscopically, and parasite identification was based on the morphology of cysts, eggs, larvae, and adult worms. Three nematodes (Oesophagostomum spp., Strongyloides sp., and Trichuris sp.), Entamoeba coli, and Entamoeba spp. were found in all five primate species. The following infections were identified: Bertiella studeri was found in chimpanzees and yellow baboons; Balantidium coli was found in yellow baboons; three nematodes (Streptopharagus, Primasubulura, an undetermined genus of Spirurina) and Dicrocoeliidae gen. sp. were found in red-tailed monkeys, vervet monkeys, and yellow baboons; Chitwoodspirura sp. was newly identified in red colobus and red-tailed monkeys; Probstmayria gombensis and Troglocorys cava were newly identified in chimpanzees, together with Troglodytella abrassarti; and Enterobius sp. was newly identified in red colobus. The parasitological data reported for red colobus, vervet monkeys, and yellow baboons in Mahale are the first reports for these species.
  • Michito Shimozuru, Akari Kamine, Toshio Tsubota
    COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY B-BIOCHEMISTRY & MOLECULAR BIOLOGY 163 2 254 - 261 2012年10月 [査読有り][通常論文]
     
    Hibernating bears survive up to 6 months without feeding by utilizing stored body fat as fuel. To investigate how bears maintain energy homeostasis during hibernation, we analyzed changes in mRNA expression of hepatic genes involved in energy metabolism throughout the hibernation period in captive, adult, female Japanese black bears (Ursus thibetanus japonicus). Real-time PCR analysis revealed down-regulation of glycolysis(e.g.. glucokinase). amino acid catabolism- (e.g., alanine aminotransferase) and de novo lipogenesis-related genes (e.g., acetyl-CoA carboxylase 1), and up-regulation of gluconeogensis- (e.g., pyruvate carboxylase), beta-oxidation- (i.e., uncoupling protein 2) and ketogenesis-related genes (i.e., 3-hydroxy-3-methylglutary-CoA synthase 2), during hibernation, compared to the active period (June). In addition, we found that glycolysis-related genes (i.e., glucokinase and pyruvate kinase) were more suppressed in the early phase of hibernation (January) compared to the late phase (March). One week after the commencement of feeding in April, expression levels of most genes returned to levels comparable to those seen in June, but beta-oxidation-related genes were still up-regulated during this period. These results suggest that the modulation of gene expression is not static, but changes throughout the hibernation period. The transcriptional modulation during hibernation represents a unique physiological adaptation to prolonged fasting in bears. (C) 2012 Elsevier Inc. All rights reserved.
  • Michito Shimozuru, Kamine Akari, Toshio Tsubota
    CANADIAN JOURNAL OF ZOOLOGY 90 8 945 - 954 2012年08月 [査読有り][通常論文]
     
    Body fat accumulation in the prehibernation period is crucial for survival and reproduction during hibernation for bears. Bear body mass increases rapidly during their autumnal hyperphagia phase, which is attributed not only to an increase in food availability, but also to physiological changes in lipid metabolism. To test this hypothesis, we investigated changes in blood biochemical values and mRNA expression levels of hepatic genes involved in lipid metabolism during the active period (June, August, October, and November) in Japanese black bears (Ursus thibetanus japonicus Schlegel, 1857), which were fed a constant ration throughout this period. Blood biochemical analysis revealed that plasma triglyceride concentrations decreased in October and November, implying that peripheral triglyceride uptake was accelerated in autumn. The liver was sampled by needle biopsy. Real-time polymerase chain reaction (PCR) analysis revealed that mRNA expressions of enzymes involved in glycolysis (glucokinase), as well as fatty acid and triglyceride synthesis (ATP-citrate lyase, acetylCoA carboxykinase 1, fatty acid synthase, and diacylglycerol O-acyltransferase 2), increased in November, which suggests that hepatic lipogenesis becomes accelerated during the hyperphagia phase. These results suggest that lipid metabolism is seasonally controlled even without changes in food intake. These physiological changes seen in the prehibernation period would contribute to the rapid mass gain necessary for hibernation.
  • Akari Kamine, Michito Shimozuru, Haruki Shibata, Toshio Tsubota
    AMERICAN JOURNAL OF VETERINARY RESEARCH 73 8 1282 - 1289 2012年08月 [査読有り][通常論文]
     
    Objective-To establish a safe anesthetic protocol with little effect on blood biochemical values and IV glucose tolerance test (IVGTT) results in Japanese black bears (Ursus thibetanus japonicus). Animals-16 captive female Japanese black bears (5 to 17 years of age). Procedures-Bears were randomly assigned to 4 treatment groups (4 bears/group) in which various treatment combinations were administered via blow dart: tiletamine HCI and zolazepam HCI (9 mg/kg) alone (TZ), TZ (6 mg/kg) and acepromazine maleate (0.1 mg/kg), TZ (6 mg/kg) and butorphanol tartrate (0.3 mg/kg), or TZ (3 mg/kg) and medetomidine HCI (40 mu g/kg). Glucose injection for the IVGTT was started 130 minutes after TZ administration. Blood samples were obtained before, at, and intermittently after glucose injection for measurement of biochemical variables as well as plasma glucose and serum insulin concentrations during the IVGTT Rectal temperature, pulse rate, and respiratory rate were assessed every 15 minutes during the experiment. Results-Induction and maintenance of anesthesia were safely achieved with little adverse effect on cardiopulmonary function when each of the 4 anesthetic regimens was used, although mild hypothermia was induced. No difference was evident between treatment groups in blood biochemical values. Blood glucose and insulin concentration profiles during the IVGTT were similar among the bears given TZ, with or without acepromazine or butorphanol, but hyperglycemia and hypoinsulinemia developed in bears given TZ with medetomidine. Conclusions and Clinical Relevance-All 4 anesthetic regimens yielded chemical restraint without affecting clinical and biochemical values in bears, but medetomidine appeared to affect IVGTT results. For this reason, medetomidine should not be used when anesthetizing bears for IVGTTs. (Am J Vet Res 2012;73:1282-1289)
  • Minami W. Okuyama, Michito Shimozuru, Nobuhiro Takahashi, Daisuke Fukui, Ryohei Nakamura, Toshio Tsubota
    JOURNAL OF VETERINARY MEDICAL SCIENCE 74 6 727 - 732 2012年06月 [査読有り][通常論文]
     
    Feral raccoons (Procyon lotor) have been increasing in number since 1979 and are currently subject to pest control in Hokkaido. One of the reasons for the increase in numbers is thought to be the high reproductive potential of raccoons, but little is known about their reproduction. The main aim of this study was to clarify seasonal changes in spermatogenesis and peripheral testosterone concentration of raccoons in Hokkaido. In the present study, external characteristics and histology of the testis and epididymis and the plasma testosterone concentration were investigated in 68 feral, male raccoons culled for pest control and once a month in one live, captive male. The feral males exhibited seasonal changes in spermatogenesis, showing active spermatogenesis in autumn, winter and spring (October June) with noted spermatogenesis and inactive spermatogenesis in summer (July September) with lower mean levels of spermatozoa in the cauda epididymis. Even in the inactive period, spermatozoa were observed in about half of the individuals (14/26); therefore, individuals producing spermatozoa existed every month throughout the year. Testosterone concentrations were significantly high in the winter mating season. In the captive male, the testosterone concentrations were low from June to August, and spermatozoa could not be observed from July to September. These results suggest that raccoons exhibit seasonality of reproduction, but the time and duration of spermatogenetic decline varies widely among individuals. This individual variation in the inactive period is a feature of male raccoon reproduction and is unique among seasonally breeding mammals.
  • Akari Kamine, Michito Shimozuru, Haruki Shibata, Toshio Tsubota
    JAPANESE JOURNAL OF VETERINARY RESEARCH 60 1 5 - 13 2012年02月 [査読有り][通常論文]
     
    The metabolic mechanisms to circannual changes in body mass of bears have yet to be elucidated. We hypothesized that the Japanese black bear (Ursus thibetanus japonicus) has a metabolic mechanism that efficiently converts carbohydrates into body fat by altering insulin sensitivity during the hyperphagic stage before hibernation. To test this hypothesis, we investigated the changes in blood biochemical values and glucose and insulin responses to intravenous glucose tolerance tests (IVGTT) during the active season (August, early and late November). Four, adult, female bears (5-17 years old) were anesthetized with 6 mg/kg TZ (tiletamine HCl and zolazepam HCl) in combination with 0.1 mg/kg acepromazine maleate. The bears were injected intravenously with glucose (0.5 g/kg of body mass), and blood samples were obtained before, at, and intermittently after glucose injection. The basal triglycerides concentration decreased significantly with increase in body mass from August to November. Basal levels of plasma glucose and serum insulin concentrations were not significantly different among groups. The results of IVGTT demonstrated the increased peripheral insulin sensitivity and glucose tolerance in early November. In contrast, peripheral insulin resistance was indicated by the exaggerated insulin response in late November. Our findings suggest that bears shift their glucose and lipid metabolism from the stage of normal activity to the hyperphagic stage in which they show lipogenic-predominant metabolism and accelerate glucose uptake by increasing the peripheral insulin sensitivity.
  • Atsushi Yamanaka, Makoto Asano, Masatsugu Suzuki, Toshio Mizoguchi, Toru Oi, Michito Shimozuru, Toshio Tsubota
    ZOOLOGICAL SCIENCE 28 2 105 - 111 2011年02月 [査読有り][通常論文]
     
    We evaluated the stored body fat of Japanese black bears (Ursus thibetanus japonicus) killed as nuisances in Gifu and Fukushima prefectures, Japan, during 2005-2007. We employed femur marrow fat (FMF), modified kidney fat index (mKFI), and abdominal subcutaneous fat (ASF) as indices for quantitative evaluation. We examined the basic characteristics of these indices, such as seasonality, age and sex dependency, and the quantitative relationship among them. mKFI and ASF increased towards the beginning of the denning period (December), while FMF was relatively stable throughout the sampling period (July-December). In cubs, all indices showed significantly lower values than in the older age classes. There seemed to be a catabolizing order between FMF and mKFI, but not between mKFI and ASF. We also evaluated the yearly change in the indices, and discussed its relevance to the incidence of bear intrusion into human residential areas. Bears nuisance-killed in summer (July-September) 2006 had a significantly larger amount of stored body fat than those killed in summer 2007, although the number of nuisance kills was larger in 2006 than in 2007. This suggests that poor nutritional condition is not a direct cause of bear intrusion.
  • 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 2011年02月 [査読有り][通常論文]
     
    In order to develop a method for estimating the success/failure rates of reproductive processes, especially those of ovulation and neonate nurturing, in the Japanese black bear (Ursus thibetanus japonicus), we examined offspring status, corpora lutea (CLs), placental scars (PSs) and corpora albicantia (CAs) in 159 females (0-23 years old) killed as nuisances on Honshu Island of Japan during 2001-2009. PSs were found to remain in the uterus at least until November of the year of parturition. CA detectability began to decline after September of the year of parturition. Monthly and age-specific proportions of CL-present females revealed that the post-mating season starts in August, and that the age of first ovulation is 4 years. These results indicate that the success rate of ovulation (SRO: the probability that solitary/non-lactating mature females actually succeed in ovulation) can be estimated by calculating the proportion of CL-present females among >= 4-year-old females without PSs captured from August to November; the early litter loss rate (ELLR: the probability that parenting females lose all of their cubs [0-year-old offspring] before mating season) can be estimated by calculating the proportion of CL-present females among those with PSs and CAs captured in August or later. The estimated values of SRO and ELLR were 0.93 (62/67) and 0.27 (6/22), respectively.
  • Mami Aoki, Michito Shimozuru, Takefumi Kikusui, Yukari Takeuchi, Yuji Mori
    ZOOLOGICAL SCIENCE 27 10 783 - 789 2010年10月 [査読有り][通常論文]
     
    Among rodents, females are generally considered to be highly responsive in terms of emotionality under stressful conditions, and have higher corticosterone levels and activity. In this study, we examined sex differences in mice by evaluating anxiety behaviors and corticosterone responses to mild stressors. In our first experiment, we analyzed the behavioral and corticosterone responses to the elevated plus-maze test and open-field test in male and female mice, and compared sex differences. Principal component analysis (PCA) was used to investigate the correlation of these responses between males and females. The corticosterone level was higher in females under both basal and stressed conditions. In the behavioral response, higher locomotor activity was seen in females in the elevated plus-maze test. PCA showed little association among anxiety behavior, locomotor activity, and corticosterone secretion. In our second experiment, we examined the activational effects of sex steroids on the corticosterone response to the elevated plus-maze test by gonadectomizing male and female mice and using testosterone or estrogen capsules as hormonal replacements. Sex differences at the basal corticosterone level were not altered by the hormonal milieu in adults, however the higher corticosterone level of females in response to stress was diminished by ovariectomy, although replacement with neither testosterone nor estrogen had any effect. These results suggest that the sex difference in novelty exposure observed in the form of a greater hypothalamic-pituitary-adrenal (HPA) axis response in female ICR mice is controlled by ovary-derived factors in adults.
  • Ruriko Iibuchi, Michito Shimozuru, Akari Kamine, Junko Nio-Kobayashi, Toshihiko Iwanaga, Toshio Tsubota
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 56 2 236 - 242 2010年04月 [査読有り][通常論文]
     
    The Japanese black bear (Ursus thibetanus japonicus) is a typical seasonal breeder that has a mating season in early summer. Spermatogenesis and testicular steroidogenesis are known to develop and regress annually; however, its molecular mechanism has not yet been investigated. In the present study, we clarified the mRNA sequence of 5 steroidogenic enzymes (P450scc, 3 beta HSD, P450c17, 17 beta HSD3 and P450arom) using RT-PCR and RACE methods and the localization of these gene expressions in the bear testis using an in situ hybridization technique. The amino acid sequence deduced from each mRNA sequence had high homology with the corresponding sequences of other species and possessed a motif typical of the P450 family or short chain alcohol dehydrogenase family. Expression of P450scc, 3 beta HSD and P450c17 mRNA in interstitial tissue indicated that conversion from cholesterol to androstenedione occurs in Leydig cells. On the other hand, the mRNA of 17 beta HSD3, which plays a central role in synthesizing testosterone, was detected not only in the interstitium but also inside the seminiferous tubules, along the basement membrane. P450arom mRNAs were distributed in the seminiferous tubules. These results suggest the possibility of testosterone and estradiol-17 beta synthesis inside the seminiferous tubules in the bear testis. We expect that the results of this study will be useful for further investigation of the molecular mechanism of steroidogenic seasonality in the bear testis.
  • Ruriko Iibuchi, Akari Kamine, Michito Shimozuru, Junko Nio-Kobayashi, Gen Watanabe, Kazuyoshi Taya, Toshio Tsubota
    JAPANESE JOURNAL OF VETERINARY RESEARCH 57 4 185 - 196 2010年02月 [査読有り][通常論文]
     
    Male Japanese black bears (Ursus thibetanus japonicus) have an explicit reproductive cycle. The objective of this study was to clarify the variation of plasma testosterone, FSH, inhibin, LH levels and testicular gonadotropin receptor mRNA expression of male bears associated with their testicular activity. Notably, this study investigated peripheral FSH concentration and localization of gonadotropin receptor mRNAs for the first time in male bears. Blood and testicular tissue samples were taken from captive, mature, male Japanese black bears during testicular active, regressive and recrudescent phases. Plasma hormone concentrations were measured by immunoassays, and gonadotropin receptor mRNA expression in the testis was investigated by in situ hybridization technique and also by real-time PCR. There were significant variations in plasma testosterone and inhibin concentrations. Changes in FSH concentration preceded these hormones with a similar tendency. Hormones started to increase during denning, and achieved the highest values at the end of the recrudescent phase for FSH and in the active phase for testosterone and inhibin. These changes in hormone concentrations were accompanied by testicular growth. In situ hybridization analysis revealed that FSH and LH receptor mRNA was possibly expressed in Sertoli cells and Leydig cells, respectively, as they are in other mammals. However, neither plasma LH concentration nor testicular gonadotropin receptor mRNA expression level varied significantly among the sampling months. These results suggest that FSH, inhibin and testosterone have roles in testicular activity in male bears. This study provides important endocrine information for comprehending seasonal reproductivity in male Japanese black bears.
  • Ruriko Iibuchi, Noriko Nakano, Tadashi Nakamura, Tadasu Urashima, Michito Shimozuru, Tetsuma Murase, Toshio Tsubota
    JAPANESE JOURNAL OF VETERINARY RESEARCH 57 1 13 - 22 2009年05月 [査読有り][通常論文]
     
    Japanese black bears, Ursus thibetanus japonicus, have been classified as a vulnerable species so that data on reproduction are needed to maintain and/or extend their population. They are known to have a peculiar style of reproduction, giving birth to their neonates and raising them during denning, a period of complete fasting. In this study, we investigated the metabolic rate and milk composition of mother bears raising neonates, and the changes in body weight of the neonates under captive conditions. Seven female bears kept in dens were weighed once a month, and the amount of energy they used was calculated. From birth, cubs were also weighed and their growth rate was determined. In addition, the milk composition was analyzed to investigate its characteristics. As a result, it was found that mother bears used 34% more energy than did solitary females. There was no significant difference in the energy used for nursing whether they had single or twin cubs. On the other hand, the body weight gain of single cubs was significantly higher than that of twin cubs, suggesting that the growth of the cubs was highly affected by the suppression of mother's energy consumption during the fasting period. The milk had high fat and low sugar concentrations. This indicates that mother bears used the fat accumulated prior to denning for their main energy source when raising cubs. Considering all results together, Japanese black bears showed remarkable efficiency in the use of energy for reproduction during the fasting period.
  • Sayaka Arata, Niwako Ogata, Michito Shimozuru, Yukari Takeuchi, Yuji Mori
    JOURNAL OF VETERINARY MEDICAL SCIENCE 70 9 971 - 975 2008年09月 [査読有り][通常論文]
     
    Monoamine transporters have roles to regulate the monoamine concentrations in synaptic clefts in the central nervous system and are the targets of antidepressants and psychostimulants. They include transporters for norepinephrine, dopamine and serotonin, which are encoded by the SLC6A2, SLC6A3, and SLC6A4 genes, respectivily. We sequenced the full lengths of the coding regions of these genes for dogs and identified four single nucleotide polymorphisms (SNPs) in SLC6A2 and four in SLC6A3. One SLC6A3 SNP was non-synonymous and caused an amino acid substitution front threonine to serine. The genotype frequencies of these polymorphisms differed significantly among five breeds with different behavioral traits, suggesting that novel SLC6A2 and SLC6A3 SNPs would provide additional useful information for behavioral genetic studies in dogs.
  • Michito Shimozuru, Takefumi Kikusui, Yukari Takeuchi, Yuji Mori
    PHYSIOLOGY & BEHAVIOR 94 3 491 - 500 2008年06月 [査読有り][通常論文]
     
    Social isolation has been shown to modify behavioral patterns and neuroendocrine function in many species. In this study, we examined the influence of post-weaning social isolation on the behavioral development and fecal testosterone and corticosterone levels of male Mongolian gerbils. In Experiment 1, isolation-reared (IR) males spent more time engaged in social-sniffing. IR males also showed more aggressive and anxiety-related behaviors than group-reared males (GR; three animals per cage). In Experiment 2, a screen-divided-reared condition (SDR) was examined in addition to GR (two males per cage) and IR males. In the SDR group, two subjects were separated by a wire mesh screen allowing for sensory communication and limited physical contact but not direct social interactions. SDR males showed similar patterns in sniffing and anxiety-related behaviors to IR males; however, an increase in aggression was not observed. No differences in fecal testosterone and corticosterone levels were found among males in different rearing conditions. These results suggest that post-weaning social isolation affects behavioral development without affecting testosterone and corticosterone levels. The behavioral changes observed may therefore be regulated by different mechanisms; increases in social-sniffing and anxiety-related behaviors may be caused by the deprivation of direct social interactions, whereas the enhancement of aggressive behaviors may be caused by the lack of sensory stimulation and limited physical contact with other individuals. (C) 2008 Elsevier Inc. All rights reserved.
  • Michito Shimozuru, Yuka Kodama, Takefumi Kikusui, Yukari Takeuchi, Yuji Mori
    DEVELOPMENTAL PSYCHOBIOLOGY 49 4 343 - 350 2007年05月 [査読有り][通常論文]
     
    We examined the influence of early weaning on the development of play-fighting behaviors and anxiety status in Wistar rats. Pups were divided into two groups, those weaned at postnatal day (PD) 16 (early-weaned group) and those weaned at PD30 (normally weaned group), and were housed in pairs of the same sex. Playful interactions were measured for each pair once a week from 4 to 7 weeks of age. Thereafter during early adulthood, all the rats were subjected to the elevated plus-maze test. The frequencies of pinning and playful attack were less in the early-weaned group than in the normally weaned group. In the elevated plus-maze test, rat pups in the early-weaned group had higher anxiety levels. The results showed that deprivation of mother-pup interactions during the preweaning period decreases affiliative interactions between cage mates, including play-fighting behaviors during the postweaning developmental period, and increases anxiety levels during early adulthood. (c) 2007 Wiley Periodicals, Inc.
  • Michito Shimozuru, Takefumi Kikusui, Yukari Takeuchi, Yuji Mori
    ZOOLOGICAL SCIENCE 24 5 427 - 433 2007年05月 [査読有り][通常論文]
     
    The ability to discriminate among individuals plays a fundamental role in the establishment of social relationships in animals. We examined how Mongolian gerbils (Meriones unguiculatus) discriminate among individuals using odor. In the first experiment, the ability of male gerbils to discriminate among five odor sources from different individuals was investigated using a habituation-dishabituation paradigm. After male gerbils had been habituated to a scent from one individual, they were exposed to familiar and unfamiliar scents from different donors simultaneously. Where urine and ventral gland secretions were used, the subjects spent more time investigating novel odors than familiar ones, suggesting that they were able to discriminate individual differences in these odor sources. However, with the scents of feces and saliva, they could detect, but could not discriminate individual differences; with scent from inside the pinnae, they could not even detect. In the second experiment, we tested whether cross-habituation occurred between the scents of urine and ventral gland secretions. A male was exposed repeatedly to urine from one of two familiar donor males during four habituation trials, and was then exposed to the ventral gland secretions from two donors simultaneously. The subject males spent more time investigating scents of ventral gland secretions, but there was no difference in the investigation time between ventral gland scents from the two donors. These results suggest that male gerbils discriminate among individuals using odors from urine and ventral gland secretions and that cross-habituation may not occur between these scents during social-memory formation.
  • Michito Shimozuru, Takefumi Kikusui, Yukari Takeuchi, Yuji Mori
    PHYSIOLOGY & BEHAVIOR 89 5 644 - 649 2006年12月 [査読有り][通常論文]
     
    Social hierarchy plays an important role in the lives of gregarious species. We investigated how social hierarchy between male Mongolian gerbils (Meriones unguiculatus) housed together before sexual maturity affected their scent-marking behavior, endocrine status and physical traits as adults. The social rank between paired males was assessed based on sexual activity in adulthood at 18 and 20 weeks of age. In most cases, the male that showed higher sexual activity at IS weeks also exhibited greater sexual performance at 20 weeks, suggesting a precedence relationship between paired males regarding reproductive opportunity. Sexually active males scent-marked more often than their cage mate, particularly after a sexual experience. No significant differences in physical traits (e.g., the weight of the ventral gland, testes and adrenal glands) or endocrine status (e.g., fecal testosterone and corticosterone levels) were found between the two males. These findings suggest that social rank between familiar males formed during cohabitation, and rank was closely correlated with scent-marking activity, but not with endocrine status. (c) 2006 Elsevier Inc. All rights reserved.
  • Michito Shimozuru, Takefumi Kikusui, Yukari Takeuchi, Yuji Mori
    PHYSIOLOGY & BEHAVIOR 88 4-5 620 - 627 2006年07月 [査読有り][通常論文]
     
    In many species, social-defeat stress induces behavioral changes in subordinate individuals. The present study examined how social-defeat stress affected scent-marking and approach behaviors in male Mongolian gerbils and whether socially defeated males selectively avoided dominant males. in Experiment 1, each of 11 gerbils was defeated by a dominant gerbil during a short social confrontation (10 min in total). For Experiment 2, the same animals were used two weeks after the end of Experiment 1. Each subject was again similarly defeated, but the two gerbils were then kept in the same cage, separated by a wire mesh for 24 h. Behavioral changes in socially defeated males were observed after social defeat; both experiments were replicated three times. After acute social defeat in Experiment 1, male gerbils did not change their scent-marking activity and frequently approached the dominant males. In contrast, males decreased scent-marking activity and approach behavior toward dominant males in Experiment 2. The amount of time defeated males approached unfamiliar males was also reduced, suggesting that social-defeat stress reduces scent-marking motivation and conspecific approach behavior rather than inducing social avoidance toward a specific individual. These findings showed that the severity of social-defeat stress is an important factor in subsequent behavioral changes in male Mongolian gerbils. (c) 2006 Elsevier Inc. All rights reserved.
  • Y Kiyokawa, M Shimozuru, T Kikusui, Y Takeuchi, Y Mori
    PHYSIOLOGY & BEHAVIOR 87 2 383 - 387 2006年02月 [査読有り][通常論文]
     
    Previously, we reported that alarm pheromone released from the perianal region of male rats aggravated stress-induced hyperthermia and increased Fos expression in the vomeronasal pathway and stress-related nuclei in pheromone-recipient rats. However, the alarm property of this pheromone in terms of behavior modification is still unclear. We recently found that this alarm pheromone could be trapped in water. Based on this finding, we developed an experimental paradigm to assess the effect of alarm pheromone on recipient behavior. Male Wistar rats were acclimatized for 5 min to an open field, where two pieces of filter paper soaked with 750 mu l of either pheromone-containing water or vehicle water were attached to the wall. Then, a small "hiding box" was placed in one corner of the field and the behavioral responses of the subject rat were recorded for 10 subsequent minutes. Exposure to alarm pheromone significantly increased defensive and risk assessment behaviors and decreased exploratory and grooming behaviors compared to the vehicle control group, indicating the alarm property of the pheromone. In addition, the comparison with previous results suggests that the alarm pheromone released from the perianal region of the male rat increases anxiety in recipients, rather than evoking a stereotyped autonomic response. (c) 4 2005 Elsevier Inc. All rights reserved.

書籍

  • 上田, 恵介, 岡ノ谷, 一夫, 菊水, 健史, 坂上, 貴之, 辻, 和希, 友永, 雅己, 中島, 定彦, 長谷川, 寿一, 松島, 俊也 (担当:分担執筆)
    東京化学同人 2013年11月 (ISBN: 9784807908370) 637p

講演・口頭発表等

  • ヒグマはオスに偏った出生地分散により近親交配を回避する  [通常講演]
    下鶴倫人, 白根ゆり, 釣賀一二三, 山中正実, 中西將尚, 石名坂豪, 葛西真輔, 能勢峰, 間野勉, 坪田敏男
    第161回日本獣医学会学術集会 2018年09月 口頭発表(一般) つくば
  • 知床半島ヒグマ個体群におけるマルチプルパターニティと近親交配の発生率  [通常講演]
    下鶴倫人, 白根ゆり, 釣賀一二三, 山中正実, 中西將尚, 石名坂豪, 葛西真輔, 能勢峰, 増田泰, 間野勉, 坪田敏男
    日本哺乳類学会2018年度大会 2018年09月 口頭発表(一般) 信州大学
  • 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  [通常講演]
    尾﨑彩, 佐鹿万里子, 下鶴倫人, 坪田敏男
    日本哺乳類学会2018年度大会 2018年09月 口頭発表(一般) 信州大学
  • Specific Molecular detection of piroplasms and characterization of a beta-tubulin gene for a novel Babesia species in Sika deer (Cervus nippo yesoensis)  [通常講演]
    Moustafa, M. A. M, Elbaz, E, Lee, K, Shimozuru, M, Sashika, M, Tsubota, T
    The 2018 Wildlife Disease Association Conference 2018年08月 ポスター発表
  • 国後島のヒグマのシンプルな食性-知床半島・白糠丘陵に生息するヒグマとの比較  [通常講演]
    中下留美子, 小林喬子, 伊藤哲治, 中村秀次, 飯島勇人, 増田泰, ログンツェフA, 大泰司紀之, 下鶴倫人, 秦彩夏, 釣賀一二三, 山中正実, 佐藤喜和
    第65会日本生態学会大会 2018年03月 ポスター発表 帯広
  • Natal dispersal pattern of brown bears in Shiretoko Peninsula, eastern Hokkaido, Japan  [通常講演]
    Shirane, Y, Yamanaka, M, Nakanishi, M, Ishinazaka, T, Nose, T, Kasai, S, Shirayanagi, M, Masuda, Y, Tsuruga, H, Mano, T, Fujimoto, Y, Osada, M, Moustarfa, MAM, Sashika, M, Tsubota, T, Shimozuru, M
    2017年11月 口頭発表(一般)
  • Occurrence rate of multiple paternity and inbreeding in the brown bear population in the Shiretoko Peninsula, Hokkaido, Japan.  [通常講演]
    Shimozuru, M, Shirane, Y, Tsuruga, H, Yamanaka, M, Nakanishi, M, Moriwaki, J, Ishinazaka, T, Kasai, S, Nose, T, Masuda, Y, Mano, T, Tsubota, T
    25th International Conference of Bear Research and Management 2017年11月 ポスター発表 キト、エクワドル International Bear Association
  • Changes in body temperature and heart rate during hibernation in captive male and female Japanese black bears (Ursus thibetanus japonicus).  [通常講演]
    Tsubota, T, Yamazaki, K, Sashika, M, Moustafa, M. A. M, Shimozuru, M
    25th International Conference of Bear Research and Managemen 2017年11月 口頭発表(一般) キト、エクワドル International Bear Association
  • 知床半島におけるヒグマの肥満度を左右する夏期の食物と軋轢発生への影響の検討  [通常講演]
    山中正実, 下鶴倫人, 白根ゆり, 中西將尚, 森文彦, 石名坂豪, 増田泰
    野生生物と社会学会第23会大会 2017年11月 ポスター発表 帯広
  • ヒグマは匂いで個体の違い・発情・非発情を区別できるか:背部脂腺から分泌される油脂性物質による嗅覚コミュニケーションの検討  [通常講演]
    豊島尚章, 成瀬泰平, 松本直也, 冨安洵平, 下鶴倫人, 佐藤喜和
    日本哺乳類学会2017年度大会 2017年09月 ポスター発表
  • 知床半島ルシャ地区におけるヒグマの繁殖特性 —長期追跡調査に基づく繁殖指標の算出—  [通常講演]
    下鶴倫人, 山中正実, 中西將尚, 白根ゆり, 石名坂豪, 葛西真輔, 能勢峰, 増田泰, 坪田敏男
    日本哺乳類学会2017年度大会 2017年09月 口頭発表(一般) 富山
  • キツネ用駆除薬ベイトを用いたエキノコックス症対策-小面積地域への摘要-  [通常講演]
    浦口宏二, 入江隆夫, 考口祐一, 八木欣平, 稲森 梓, 下鶴倫人, 坪田敏男
    日本哺乳類学会2016年度大会 2016年09月 口頭発表(一般) つくば
  • 知床半島におけるヒグマの個体群動向モニタリングの試み  [通常講演]
    山中正実, 下鶴倫人, 中西將尚, 間野勉, 白根ゆり, 増田泰
    日本哺乳類学会2016年度大会 2016年09月 ポスター発表 つくば
  • ヒグマは匂いで個体の違いを識別できるか:背部脂腺から分泌される油脂性物質による嗅覚コミュニケーションの検討.  [通常講演]
    豊島尚章, 成瀬泰平, 松本直也, 冨安洵平, 下鶴倫人, 佐藤喜和
    日本哺乳類学会2016年度大会 2016年09月 ポスター発表 つくば
  • 知床半島におけるヒグマの移動分散様式の解明  [通常講演]
    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2016年度大会 2016年09月 口頭発表(一般) つくば
  • ヒグマの夏期の食物資源の豊凶が栄養状態および子の生存に与える影響  [通常講演]
    下鶴倫人, 森文彦, 白根ゆり, 山中正実, 中西將尚, 坪田敏男
    日本哺乳類学会2016年度大会 2016年09月 ポスター発表 つくば
  • 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  [通常講演]
    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
    第22回日本野生動物医学会宮崎大会 2016年09月 口頭発表(一般) 宮崎
  • 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  [通常講演]
    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
    第159回日本獣医学会学術集会 2016年09月 口頭発表(一般) 藤沢
  • 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  [通常講演]
    浦口宏二, 孝口裕一, 入江隆夫, 稲森 梓, 下鶴倫人, 坪田敏男
    第159回日本獣医学会学術集会 2016年09月 口頭発表(一般) 藤沢
  • Regulation of protein metabolism and muscle mass in hibernating bears: an attractive model of muscle atrophy.  [通常講演]
    Miyazaki, M, Shimozuru, M, Tsubota, T
    2016年06月 口頭発表(一般) アラスカ, アメリカ合衆国
  • Changes in energy metabolism in hibernating black bears: an analysis of gene expression and metabolites in liver and skeletal muscle.  [通常講演]
    Shimozuru, M, Miyazaki M, Tsubota, T
    2016年06月 口頭発表(一般) アラスカ, アメリカ合衆国
  • Changes in body temperature and heart rate related to hibernation in captive Japanese black bears.  [通常講演]
    Tsubota, T, Suzuki, S, Miyagi, D, Yamazaki, K, Sashika, M, Shimozuru, M
    24th International Conference of Bear Research and Management 2016年06月 口頭発表(一般) アラスカ, アメリカ合衆国
  • Cross-cluster genetic exchange of the brown bear population occurs at the base of Shiretoko Peninsula.  [通常講演]
    Tsubota, T, Hirano, S, Nagano, N, Tsujino, M, Shimozuru, M, Sashika, M, Osada, M, Fujimoto, Y
    5th International Wildlife Management Congress 2015年09月 口頭発表(一般) 札幌
  • 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  [通常講演]
    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
    第158回日本獣医学会学術集会 2015年09月 口頭発表(一般) 十和田
  • 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どう量測定の試み  [通常講演]
    鈴木信吾, 山崎晃司, 佐鹿万里子, 下鶴倫人, 坪田敏男
    第158回日本獣医学会学術集会 2015年09月 口頭発表(一般) 十和田
  • Reproductive parameters and male dispersal of brown bears in the Rusha area of Shiretoko National Park, Hokkaido, Japan.  [通常講演]
    Shimozuru, M, Moriwaki, J, Yamanaka, M, Nakanishi, M, Ishinazaka, T, Kasai, S, Nose, T, Masuda, Y, Tsubota, T
    5th International Wildlife Management Congress 2015年07月 ポスター発表 札幌
  • Tuberculosis in Asian elephants (Elephas maximus) of Nepal.  [通常講演]
    Paudel, S, Mikota, S. K, Nakajima, C, Gairhe, K. P, Poudel, A, Sashika, M, Shimozuru, M, Suzuki, Y, Tsubota, T
    5th International Wildlife Management Congress 2015年07月 口頭発表(一般) 札幌
  • Niche selection by microbes: Babesia and Erlichiae exhibit host preference among rodents sharing ecosystems in Hokkaido, Japan.  [通常講演]
    Moustafa, M. Jr, Taylor, K, Nakao, R, Sashika, M, Shimozuru, M, Tsubota, T
    5th International Wildlife Management Congress 2015年07月 口頭発表(一般) 札幌
  • Hibernating bear muscle shows slow-fiber shifting and mitochondrial biogenesis despite prolonged physical inactivity  [通常講演]
    Miyazaki, M, Shimozuru, M, Tsubota, T
    Cell Symposium Exercise Metabolism 2015年07月 口頭発表(一般) アムステルダム
  • 知床半島におけるヒグマの移動分散について –知床半島ヒグマ保護管理方針に対する保護管理上の示唆–  [通常講演]
    山中正実, 下鶴倫人, 中西將尚, 増田泰, 坪田敏男
    「野生生物と社会」学会第20回大会 2014年10月 口頭発表(一般) 犬山
  • A relapsing fever group Borrelia sp. Similar to Borrelia lonestari found among wild sika deer (Cervus Nippon yesoensis) and Heamaphysalis spp. ticks in Hokkaido, Japan.  [通常講演]
    Lee, K, Takano, A, Taylor, K, Sashika, M, Shimozuru, M, Konnai, S, Kawabata, H, Tsubota, T
    7th Asian Meeting on Zoo and Wildlife Medicine/Conservation 2014年10月 口頭発表(一般) ハノイ, ベトナム
  • Interferon-gamma release assay (IGRA) for the diagnosis of tuberculosis in Asian elephants (Elephas maximus).  [通常講演]
    Paudel, S, Villanueva, M, Mikota, S. K, Nakajima, C, Gairhe, K. P, Subedi, S, Rayamajhi, N, Sashika, M, Shimozuru, M, Suzuki, Y, Tsubota, T
    7th Asian Meeting on Zoo and Wildlife Medicine/Conservation 2014年10月 口頭発表(一般) ハノイ, ベトナム
  • A RF Borrelia sp. found among wild sika deer and Haemaphysalis ticks in Hokkaido.  [通常講演]
    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
    第157回日本獣医学会学術集会 2014年09月 口頭発表(一般) 札幌
  • 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  [通常講演]
    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
    第157回日本獣医学会学術集会 2014年09月 口頭発表(一般) 札幌
  • 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  [通常講演]
    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
    第157回日本獣医学会学術集会 2014年09月 口頭発表(一般) 札幌
  • 腎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  [通常講演]
    森真理子, 佐鹿万里子, 下鶴倫人, 坪田敏男
    日本哺乳類学会2014年度大会 2014年09月 ポスター発表 京都
  • 知床半島ルシャ地区におけるヒグマの行動特性と遺伝構造  [通常講演]
    下鶴倫人
    日本哺乳類学会2014年度大会 2014年09月 シンポジウム・ワークショップパネル(指名) 京都
  • Molecular epidemiological study on Anaplasma phagocytophilum in sika deer (Cervus nippon) in Hokkaido, Japan.  [通常講演]
    Moustafa, M, Lee, K, Taylor, K, Sashika, M, Shimozuru, M, Tsubota, T
    63rd Annual International Conference of the Wildlife Disease Association 2014年07月 口頭発表(一般) ニューメキシコ, アメリカ合衆国
  • 知床半島ルシャ地域におけるヒグマの血縁関係解析  [通常講演]
    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
    日本哺乳類学会2013年度大会 2013年09月 ポスター発表 岡山
  • ヒグマにとって厳しかった夏−2012年、知床半島での事例−  [通常講演]
    下鶴倫人, 森脇 潤, 山中正実, 中西將尚, 石名坂豪, 葛西真輔, 白柳正隆, 能勢 峰, 増田 泰, 坪田敏男
    日本哺乳類学会2013年度大会 2013年09月 口頭発表(一般) 岡山
  • 尿道カテーテル法を応用したニホンザルの精液採取  [通常講演]
    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
    第19回日本野生動物医学会大会 2013年08月 口頭発表(一般) 京都
  • Characterization of Mycobacterium tuberculosis isolates from captive elephants of Nepal.  [通常講演]
    Paudel, S, Mikota, SK, Nakajima, C, Gairhe, KP, Maharjan, B, Thapa, J, Poudel, A, Shimozuru, M, Suzuki, Y, Tsubota, T
    62nd International Conference of Wildlife Disease Organization 2013年07月 口頭発表(一般) Knoxville, TN, USA
  • Body temperature and blood biochemical profiles during hibernation in the Japanese black bear.  [通常講演]
    Tsubota, T, Shimozuru, M
    14th International Hibernation Symposium 2012年08月 口頭発表(一般) Semmering, Austria
  • Seasonal changes in expression of energy metabolism-related genes in the liver and white adipose tissue of captive, adult, female Japanese black bears.  [通常講演]
    Shimozuru, M, Nagashima, A, Kamine, A, Tsubota, T
    14th International Hibernation Symposium 2012年08月 ポスター発表 Semmering, Austria
  • Rodent dynamics and Borrelia spp. Infection rates in Hokkaido.  [通常講演]
    Taylor, K.R, 高野愛, 川端寛樹, 下鶴倫人, 坪田敏男
    第153回日本獣医学会学術集会 2012年03月 口頭発表(一般) 大宮
  • Behavior and genetic structure of Hokkaido brown bears, Ursus arctos yesoensis in eastern Hokkaido  [通常講演]
    Hirano, S, Shimozuru, M, Tsubota, T, Fujimoto, Y, Osada, M, Ueno, H, Yamanaka, M
    第59回日本生態学会大会 2012年03月 口頭発表(一般) 大津
  • DNA分析のためのダートバイオプシーによる野生ヒグマの組織標本採取の試み  [通常講演]
    山中正実, 森脇潤, 坪田敏男, 中西将尚, 下鶴倫人
    第17回野生生物保護学会大会 2011年10月 ポスター発表 網走
  • Changes in expression of hepatic genes involved in energy metabolism during the hibernation period in Japanese black bears  [通常講演]
    Shimozuru, M, Kamine, A, Tsubota, T
    20th International Conference on Bear Research & Management 2011年07月 ポスター発表 Ottawa, Canada
  • 道東標津町における携帯電話を利用したリアルタイム通信によるヒグマ行動追跡  [通常講演]
    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
    第58回日本生態学会大会 2011年03月 口頭発表(一般) 札幌
  • ニホンツキノワグマ(Ursus thibetanus unguiculatus)における排卵確率の推定  [通常講演]
    山中淳史, 山内貴義, 辻元恒徳, 溝口俊夫, 大井徹, 澤田誠吾, 下鶴倫人, 坪田敏男
    第16回野生生物保護学会・日本哺乳類学会2010年度合同大会 2010年09月 口頭発表(一般) 岐阜
  • ツキノワグマからのCytauxzoon原虫の検出と分離  [通常講演]
    陣内理生, 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
    第150回日本獣医学会学術集会 2010年09月 口頭発表(一般) 帯広
  • 北海道における雄アライグマの性成熟時期の解明  [通常講演]
    奥山みなみ, 福井大祐, 中村亮平, 高橋伸広, 下鶴倫人, 坪田敏男
    第103回日本繁殖生物学会 2010年09月 口頭発表(一般) 十和田
  • Changes in biochemical values of captive Japanese black bears during active and hibernation phases  [通常講演]
    Kamine, A, Iibuchi, R, Shimozuru, M, Tsubota, T
    19th International Conference on Bear Research & Management 2010年05月 ポスター発表 Tbilisi, Georgia Republic
  • ニホンツキノワグマにおける冬眠中の行動および体温変化の解析  [通常講演]
    下鶴倫人, 吉本拓郎, 坪田敏男
    日本哺乳類学会2009年大会 2009年11月 ポスター発表 台北、台湾
  • Physiological and endocrinological mechanism for nutritional condition reproduction related to hibernation in the Japanese black bear (Ursus thibetanus japonicus)  [通常講演]
    Tsubota, T, Nakamura, S, Iibuchi, R, Kamine, A, Shimozuru, M
    International Symposium on Conservation of Asiatic Black Bear 2009年11月 ポスター発表
  • Parasite ecology of primates in Mahale Mountains National Park, Tanzania.  [通常講演]
    Kooriyama, T, Iwaki, T, Nishida, T, Shimozuru, M, Tsubota, T
    The 3rd International Workshop of Asian Society of Zoo and Wildlife Medicine & The 1st Meeting of Korean Society of Zoo and Wildlife Medicine 2009年08月 口頭発表(一般) Seoul, Korea
  • Changes in plasma testosterone concentration and spermatogenesis around the mating season in juvenile and adult captive raccoons (Procyon lotor).  [通常講演]
    Okuyama, M, Fukui, D, Takahashi, N, Nakamura R, Shimozuru, M, Tsubota, T
    The 3rd International Workshop of Asian Society of Zoo and Wildlife Medicine & The 1st Meeting of Korean Society of Zoo and Wildlife Medicine 2009年08月 口頭発表(一般) Seoul, Korea
  • TPR profiles, and plasma glucose and fat concentration of male Japanese black bears (Ursus thibetanus japonicus) during hibernation.  [通常講演]
    Iibuchi, R, Kamine, A, Shimozuru, M, Tsubota, T
    The 3rd International Workshop of Asian Society of Zoo and Wildlife Medicine & The 1st Meeting of Korean Society of Zoo and Wildlife Medicine 2009年08月 口頭発表(一般) Seoul, Korea
  • 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  [通常講演]
    飯渕るり子, 岩永敏彦, 下鶴倫人, 坪田敏男
    第147回日本獣医学会学術集会 2009年04月 口頭発表(一般) 宇都宮
  • 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  [通常講演]
    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
    第147回日本獣医学会学術集会 2009年04月 口頭発表(一般) 宇都宮
  • ニホンツキノワグマにおける血中グルコース動態とインスリン応答の季節変化  [通常講演]
    加味根あかり, 飯渕るり子, 柴田治樹, 下鶴倫人, 坪田敏男
    第146回日本獣医学術集会 2008年09月 口頭発表(一般) 宇都宮
  • ニホンツキノワグマ(Ursus thibetanus japonicus)における冬眠中の血中代謝関連成分の変化  [通常講演]
    飯渕るり子, 加味根あかり, 下鶴倫人, 坪田敏男
    第146回日本獣医学術集会 2008年09月 口頭発表(一般) 宮崎
  • ニホンツキノワグマ(Ursus thibetanus japonicus)の有害捕獲数と捕獲個体の栄養状態に関連はあるのか?  [通常講演]
    山中淳史, 浅野玄, 鈴木正嗣, 溝口俊夫, 下鶴倫人, 坪田敏男
    第14回日本野生動物医学会大会 2008年09月 口頭発表(一般) 神戸

その他活動・業績

受賞

  • 2020年04月 羅臼町 感謝状
     ヒグマ対策におけるDNA分析の協力に対する感謝状
  • 2016年09月 日本哺乳類学会 優秀発表賞
     知床半島におけるヒグマの移動分散様式の解明 
    受賞者: 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
  • 2012年09月 日本哺乳類学会 最優秀ポスター賞
     知床半島ルシャ地域におけるヒグマの個体モニタリング調査の試み 
    受賞者: 森脇潤;下鶴倫人;山中正実;中西将尚;増田泰;藤本靖;坪田敏男

共同研究・競争的資金等の研究課題

  • 増えすぎたシカはヒグマにとって恵みか災いか? ヒグマとシカの種間関係に関する研究
    日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2019年04月 -2022年03月 
    代表者 : 下鶴 倫人
  • 遺産価値向上に向けた知床半島における大型哺乳類の保全管理手法の開発
    環境再生保全機構:環境研究総合推進費
    研究期間 : 2019年04月 -2021年03月 
    代表者 : 宇野裕之(研究代表者), 下鶴倫人(サブテーマリーダー), 石名坂豪(サブテーマリーダー)
  • ツキノワグマにおける冬眠中の体温調節機構の解明-ふるえ産熱か非ふるえ産熱か-
    日本学術振興会:科学研究費助成事業 基盤研究(B)
    研究期間 : 2017年04月 -2020年03月 
    代表者 : 坪田 敏男, 宮崎 充功, 佐鹿 万里子, 下鶴 倫人, MOHAMED MOUSTAFA, 岡松 優子
     
    2年目となった2018年度は、4月に研究計画について北秋田市観光課担当者と打合せを行った上で、5月より実験を開始した。昨年度オス・ツキノワグマ7頭に埋め込んだ体温、心拍数および活動量モニタリング用デバイス(DST centi-HRT ACT, STARODDI)を取り出して、データを吸い出した。7月には、去勢オス3頭(1頭はこの時に去勢手術実施)に同デバイスを胸部皮下に埋め込んだ。続いて11月に、正常オス4頭に同デバイスおよびi-Buttonを胸部および頸部皮下に埋め込むととともに、血液および脂肪組織を採取した。さらに、1月および3月に同じ正常オス4頭より血液および脂肪組織を採取した。得られた血液を使って性ホルモン測定を行った。また、脂肪組織を使って細胞培養および非ふるえ産熱に関わる代謝系の遺伝子およびタンパク質発現について調べた。さらに、冬眠明け時期に北海道標津町にて捕殺したヒグマの頸部脂肪組織を採取して、飼育下実験と同様に、白色脂肪組織による非ふるえ産熱の有無について調べている。
  • ヒグマに学ぶ健康 〜急激な肥満と長期の絶食を可能にする腸内細菌叢の解明〜
    秋山記念生命科学振興財団:研究助成(一般)
    研究期間 : 2019年04月 -2020年03月
  • 知床国立公園とその周辺におけるヒグマと人の共存の道を探る調査研究
    富士フィルム:富士フィルムグリーンファンド
    研究期間 : 2017年04月 -2019年03月 
    代表者 : 下鶴倫人
  • クマにおける冬眠中のエネルギー代謝制御に関わる血中分泌型microRNAの探索
    文部科学省:科学研究費補助金 基盤研究(C)
    研究期間 : 2016年04月 -2019年03月 
    代表者 : 下鶴倫人
  • 地球温暖化による食物環境の変化はヒグマの生態にどのような影響を及ぼすのか?
    三井物産:三井物産環境基金
    研究期間 : 2015年04月 -2018年03月 
    代表者 : 下鶴倫人
  • 日本学術振興会:科学研究費助成事業 挑戦的萌芽研究
    研究期間 : 2014年04月 -2017年03月 
    代表者 : 宮崎 充功, 坪田 敏男, 下鶴 倫人
     
    本研究では、「冬眠」を長期間の寝たきり状態と仮定して、冬眠動物(ツキノワグマ)がどのような仕組みを利用して骨格筋量を維持しているのか、筋肉細胞の中のタンパク質や遺伝子の働きに注目して解析しました。その結果、骨格筋量の維持に影響を与える因子のうち、筋タンパク質合成を促進する命令系統が冬眠後の筋肉で活性化されていることや、筋肉が大きくなり過ぎないようリミッターの役割をしている遺伝子の働きが冬眠中に抑えられていること、などがわかりました。
  • 日本学術振興会:科学研究費助成事業 基盤研究(C)
    研究期間 : 2014年04月 -2017年03月 
    代表者 : 坪田 敏男, 佐鹿 万里子, 下鶴 倫人
     
    北秋田市阿仁クマ牧場(くまくま園)で飼育されている5頭の成熟雌ツキノワグマを対象にして、胸部皮下に心拍・体温測定用ロガー(DST milli-HRT、Star:Oddi)を埋め込み、冬眠前から冬眠後の約6ヶ月間、心拍数および皮下体温をモニタリングした。1月には超音波画像診断装置をを使って妊娠診断を行った。特筆すべき研究成果として、妊娠個体の体温と心拍数の関係において、冬眠前時期(着床遅延期間)には両者はおよそ24時間周期の変化を示したが、冬眠導入後の胎子発育時期には高体温を維持しながら心拍数は一過性のピークを示し、出産後には体温と心拍数が同調して周期性のない数日間隔での増減を繰り返した。
  • なぜクマは冬眠中に骨格筋が萎縮しないのか? —冬眠中の筋蛋白同化/異化様式の解明—
    文部科学省:科学研究費補助金 若手研究(B)
    研究期間 : 2014年04月 -2016年03月 
    代表者 : 下鶴倫人
  • 文部科学省:科学研究費補助金(若手研究(B))
    研究期間 : 2011年 -2011年 
    代表者 : 下鶴 倫人
  • 文部科学省:科学研究費補助金(基盤研究(C))
    研究期間 : 2009年 -2011年 
    代表者 : 坪田 敏男, 下鶴 倫人
     
    本研究では、なぜクマは体脂肪率30~40%の肥満状態でも脂肪肝や高脂肪血症を発症しないのか、その特徴的な体脂肪蓄積メカニズムを明らかにすることを目的にして次のような実験を行った。実験は、秋田県北秋田市マタギの里阿仁クマ牧場において、5~11月にかけて月1回行った。1回の実験に4頭のツキノワグマを用いた。塩酸チレタミンと塩酸ゾラゼパムの混合薬(Zoletil 100、Virbac、フランス)9mg/kgにより不動化を行い、麻酔状態下で以下のサンプリングおよび実験を行った。なお、使用したツキノワグマは前日の夕方5:00以降は絶食状態とした。1)基底レベルの血中グルコース、インスリン、中性脂肪、コレステロールおよび遊離脂肪酸濃度を測定した。血中グルコースおよびインスリン濃度には月別の変化は見られなかったが、血中中性脂肪、コレステロールおよび遊離脂肪酸濃度は冬眠前に減少する傾向にあった。2)グルコース投与後0~180分までおよそ30分間隔で血中グルコースおよびインスリン濃度を測定した。その結果、グルコース投与後血中グルコース濃度は一過性に上昇した後、徐々に減少し180分後にはおよそ基底値まで減少した。減少のスピードに月別変化はみられなかった。一方、血中インスリン濃度はグルコース投与直後から上昇し、およそ30分でピークに達した。この時のインスリン上昇度は11月で最も著しい傾向を示した(...
  • ツキノワグマにおける冬眠に関わる自律神経機構の解明
    北海道大学:公募型プロジェクト研究等支援経費
    研究期間 : 2008年04月 -2009年03月 
    代表者 : 下鶴倫人

教育活動情報

主要な担当授業

  • 先端獣医科学特論A 行動解析学特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学研究科
  • 大学院共通授業科目(一般科目):自然科学・応用科学
    開講年度 : 2018年
    課程区分 : 修士課程
    開講学部 : 大学院共通科目
  • 獣医科学基礎科目A 野生動物/保全医学特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学研究科
  • 動物行動学
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部
  • 獣医科学基礎科目 環境獣医科学特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学院
  • 野生動物学演習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部
    キーワード : 保全生態学、野生動物医学、保全医学、生態系、保護管理
  • 先端獣医科学科目 野生動物/保全医学特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学院
  • 保全生態・野生動物医学演習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部
  • アドバンスト演習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部

大学運営

委員歴

  • 2019年04月 - 現在   日本野生動物医学会   学術誌編集委員
  • 2019年01月 - 現在   日本動物行動学会   副編集長
  • 2018年04月 - 現在   日本クマネットワーク   事務局長
  • 2014年04月 - 現在   日本獣医学会   野生動物分科会 事務局・会計
  • 2014年04月 - 現在   日本獣医学会   評議員
  • 2011年04月 - 現在   日本野生動物医学会   評議員
  • 2010年04月 - 2013年03月   日本野生動物医学会   幹事(広報)


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