研究者データベース

柳川 洋二郎(ヤナガワ ヨウジロウ)
獣医学研究院 獣医学部門 臨床獣医科学分野
助教

基本情報

所属

  • 獣医学研究院 獣医学部門 臨床獣医科学分野

職名

  • 助教

学位

  • 博士(獣医学)(北海道大学)

J-Global ID

研究キーワード

  • 繁殖学   野生動物   

研究分野

  • 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
  • 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
  • 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

職歴

  • 2011年04月 - 現在 北海道大学
  • 2011年04月 - 現在 北海道大学 助教

学歴

  • 2005年04月 - 2009年03月   北海道大学
  •         - 2009年03月   北海道大学   獣医学研究科
  • 1999年04月 - 2005年03月   Tokyo University of Agiriculture and Technology
  •         - 2005年03月   東京農工大学   農学部   獣医学科

所属学協会

  • 日本哺乳類学会   日本野生動物医学会   日本獣医師会   日本獣医学会   

研究活動情報

論文

  • Sakaguchi K, Maylem ERS, Tilwani RC, Yanagawa Y, Katagiri S, Atabay EC, Atabay EP, Nagano M
    Animal science journal = Nihon chikusan Gakkaiho 2019年03月 [査読有り][通常論文]
  • Akizawa H, Yanagawa Y, Nagano M, Bai H, Takahashi M, Kawahara M
    Animal science journal = Nihon chikusan Gakkaiho 90 1 49 - 54 2019年01月 [査読有り][通常論文]
  • Sakaguchi K, Tanida T, Abdel-Ghani MA, Kanno C, Yanagawa Y, Katagiri S, Nagano M
    The Journal of reproduction and development 2018年08月 [査読有り][通常論文]
  • Abdel-Ghani Mohammed. A, Sakaguchi Kenichiro, Kanno Chihiro, Yanagawa Yojiro, Katagiri Seiji, Nagano Masashi
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 64 4 365 - 369 2018年08月 [査読有り][通常論文]
  • Tomiyasu J, Kondoh D, Yanagawa Y, Sato Y, Sakamoto H, Matsumoto N, Sasaki K, Haneda S, Matsui M
    The Journal of veterinary medical science 80 6 1034 - 1040 2018年06月 [査読有り][通常論文]
  • Sakaguchi K, Ideta A, Yanagawa Y, Nagano M, Katagiri S, Konishi M
    The Journal of reproduction and development 2018年06月 [査読有り][通常論文]
  • Toishi Yuko, Tsunoda Nobuo, Nagata Shun-ichi, Kirisawa Rikio, Nagaoka Kentaro, Watanabe Gen, Yanagawa Yojiro, Katagiri Seiji, Taya Kazuyoshi
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 64 1 41 - 47 2018年02月 [査読有り][通常論文]
  • 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.
  • Tomochika Sugiura, Shun Akiyoshi, Fumihiro Inoue, Yojiro Yanagawa, Masaharu Moriyoshi, Motoshi Tajima, Seiji Katagiri
    Journal of Reproduction and Development 64 2 135 - 143 2018年 [査読有り][通常論文]
     
    The objective of this study was to investigate cyclical changes in endometrial thickness in relation to progesterone (P4) and estradiol-17β (E2) concentrations during natural and induced estrus in 15 cows. In the prostaglandin (PG) F2α-induced estrus group, ultrasonography (USG) at 6-h intervals was used to determine endometrial thickness 48–24 h before the PGF2α treatment until 24 h after ovulation (ovulation = Day 0). In the natural estrus group, USG was performed every 48 h from Day 3 to Days 15–18 after the first ovulation, and then every 6 h until 24 h after ovulation. Endometrial thickness was standardized using Day 13 as a reference day. Blood was collected during every USG examination and plasma P4 and E2 concentrations were determined. Endometrial thickness of the induced estrus group (n = 11) was greater than that of the natural estrus group (n = 9) between 60 and 12 h before ovulation (P < 0.05). In the natural estrus group, prior to an increase in endometrial thickness, a decrease in P4 and an increase in E2 were detected. In the induced estrus group, based on the time of ovulation, an increase in endometrial thickness was detected at the same time of a decrease in P4 before an increase in E2. These results suggest that decreases in P4 concentrations may be a cue to changes in endometrial thickness, while increases in E2 concentrations appear to sustain and/or enhance these changes.
  • Yinghua Yang, Chihiro Kanno, Kenichiro Sakaguchi, Yojiro Yanagawa, Seiji Katagiri, Masashi Nagano
    ANIMAL SCIENCE JOURNAL 88 11 1686 - 1691 2017年11月 [査読有り][通常論文]
     
    Bone morphogenetic protein-4 (BMP-4) inhibits luteinization of granulosa cells during invitro growth (IVG) culture of bovine oocytes; however, oocytes derived from a 12 day IVG were less competent for development than invivo-grown oocytes. We herein investigated whether an extended IVG culture with BMP-4 improves oocyte growth and development to blastocysts after invitro fertilization. Oocyte-granulosa cell complexes (OGCs) were cultured for 14 or 16days with BMP-4 (10ng/mL), while a 12 day culture with BMP-4 served as the invitro control. OGC viability was maintained for the 16 day culture with BMP-4 (83.2%), but was significantly lower without BMP-4 (58.9%) than the control (83.0%). Prolong-cultured oocytes at 16days had statistically greater diameter (114.6m) than the control (111.7m). IVG oocytes with BMP-4 for the 16 day culture had a similar nuclear maturation rate to the control (approximately 67%); however, blastocyst rates in BMP-4 treated oocytes of 14 (1.8%) and 16 day (0%) IVG were statistically lower than that of 12 day IVG (9.0%). In conclusion, BMP-4 maintained OGC viability and promoted oocyte growth in a prolonged culture, but impaired the developmental competence of oocytes. Prolonged culture may not be an appropriate strategy for enhancing the developmental competence of IVG oocytes.
  • Wenjing Yan, Chihiro Kanno, Eiki Oshima, Yukiko Kuzuma, Sung Woo Kim, Hanako Bai, Masashi Takahashi, Yojiro Yanagawa, Masashi Nagano, Jun-ichi Wakamatsu, Manabu Kawahara
    ANIMAL REPRODUCTION SCIENCE 185 195 - 204 2017年10月 [査読有り][通常論文]
     
    Improving sperm motility and viability are major goals to improve efficiency in the poultry industry. In this study, the effects of supplemental dietary turmeric by-product (TBP) from commercial turmeric production on sperm motility, viability, and antioxidative status were examined in domestic fowl. Mature Rhode Island Red roosters were divided into two groups controls (group C) without TBP administration and test subjects (group T) fed a basal diet supplemented with 0.8 g of TBP/day in a temperature-controlled rearing facility (Experiment 1) and 1.6 g/day under heat stress (Experiment 2) for 4 weeks. In Experiment 1, TBP dietary supplementation increased the sperm motility variables straight-line velocity, curvilinear velocity, and linearity based on a computer-assisted semen analysis, 2 weeks following TBP supplementation. In Experiment 2, using flow cytometry, sperm viability at 3 and 4 weeks following TBP supplementation was greater in Group T than C, and this increase was consistent with a reduction in reactive oxygen species (ROS) production at 2 and 4 weeks. The results of both experiments clearly demonstrate that dietary supplementation with TBP enhanced sperm motility in the controlled-temperature conditions as well as sperm viability, and reduced ROS generation when heat stress prevailed. Considering its potential application in a range of environments, TBP may serve as an economical and potent antioxidant to improve rooster fertility.
  • Kei Fukuda, Yukihiro Inoguchi, Kenji Ichiyanagi, Tomoko Ichiyanagi, Yasuhiro Go, Masashi Nagano, Yojiro Yanagawa, Noboru Takaesu, Yasuyuki Ohkawa, Hiroo Imai, Hiroyuki Sasaki
    HUMAN MOLECULAR GENETICS 26 18 3508 - 3519 2017年09月 [査読有り][通常論文]
     
    Changes in gene expression resulting from epigenetic and/or genetic changes play an important role in the evolutionary divergence of phenotypes. To explore how epigenetic and genetic changes are linked during primate evolution, we have compared the genome-wide DNA methylation profiles (methylomes) of humans and chimpanzees, which have a 1.2% DNA sequence divergence, of sperm, the frontal cortices, B cells, and neutrophils. We revealed that species-specific differentially methylated regions (S-DMRs), ranging from several hundred base pairs (bp) to several kilo base pairs (kb), were frequently associated with sequence changes in transcription factor-binding sites and insertions of Alu and SVA retrotransposons. We then generated a reference macaque sperm methylome map and revealed, in sperm, that both human and chimpanzee S-DMRs arose more frequently owing to methylation loss rather than gain. Moreover, we observed that the sperm methylomes contained many more hypomethylated domains (HMDs), ranging from 20 to 500 kb, than did the somatic methylomes. Interestingly, the sperm HMDs changed rapidly during primate evolution; hundreds of sperm HMDs were specific to humans, whereas most somatic HMDs were highly conserved between humans and chimpanzees. Notably, these human-specific sperm HMDs frequently occurred in regions exhibiting copy number variations. Our findings indicate that primate evolution, particularly in the germline, is significantly impacted by reciprocal changes in the genome and epigenome.
  • Chihiro Kanno, Yojiro Yanagawa, Yoshiyuki Takahashi, Seiji Katagiri, Masashi Nagano
    JAPANESE JOURNAL OF VETERINARY RESEARCH 65 3 151 - 157 2017年08月 [査読有り][通常論文]
     
    To verify the dynamics of damages to spermatozoa during semen freezing, characteristics of spermatozoa collected from 3 Japanese black bulls were evaluated by using fluorescent staining. Pre-diluted sample showed the highest proportion of spermatozoa with intact plasma membrane, intact acrosome and high mitochondrial potential. The proportion of spermatozoa with intact plasma membrane, intact acrosome, and low mitochondrial membrane potential were higher after cooling to 4 degrees C than the other processes. During cooling preservation examined in this study, the proportion of spermatozoa with damaged acrosome increased. These results lead us to speculate that, during cooling process, spermatozoa may be firstly injured to mitochondrial membrane, and low mitochondrial function may cause the impairment of plasma membrane and subsequent cell death with acrosomal damage.
  • Chihiro Kanno, Kentaro Q. Sakamoto, Yojiro Yanagawa, Yoshiyuki Takahashi, Seiji Katagiri, Masashi Nagano
    JOURNAL OF VETERINARY MEDICAL SCIENCE 79 8 1359 - 1365 2017年08月 [査読有り][通常論文]
     
    In the present study, bull sperm in the first and second ejaculates were divided into subpopulations based on their motility characteristics using a cluster analysis of data from computer-assisted sperm motility analysis (CASA). Semen samples were collected from 4 Japanese black bulls. Data from 9,228 motile sperm were classified into 4 clusters; 1) very rapid and progressively motile sperm, 2) rapid and circularly motile sperm with widely moving heads, 3) moderately motile sperm with heads moving frequently in a short length, and 4) poorly motile sperm. The percentage of cluster 1 varied between bulls. The first ejaculates had a higher proportion of cluster 2 and lower proportion of cluster 3 than the second ejaculates.
  • Kenichiro Sakaguchi, Weiping Huang, Yinghua Yang, Yojiro Yanagawa, Masashi Nagano
    THERIOGENOLOGY 97 113 - 123 2017年07月 [査読有り][通常論文]
     
    Bone morphogenetic protein-4 (BMP-4) and FSH play important regulatory roles in follicular growth and steroidogenesis in vivo. The purpose of this study was to investigate the effects of BMP-4 and FSH on in vitro growth (IVG) and steroidogenesis of bovine oocyte-cumulus-granulosa complexes (OCGCs). We cultured OCGCs collected from early antral follicles (0.5-1 mm) in medium without BMP-4 and FSH for 4 days and investigated the appearance of OCGCs and their steroidogenesis. During the first 4 days of IVG, morphologically normal OCGCs produced more estradiol-17 beta (E-2), but less progesterone (P-4). Morphologically normal OCGCs were subjected to an additional culture in medium supplemented with BMP-4 (0, 10, and 50 ng/mL) and FSH (0 and 0.5 ng/mL) until day 12. We examined the viability and steroidogenesis of OCGCs after 8 and 12 days of culture. Oocyte growth, characteristics of granulosa cells, and the maturational competence of oocytes were also investigated. On day 8, the viability of OCGCs cultured without FSH was higher in the 10 ng/mL BMP-4 group than in the 50 ng/mL BMP-4 group (P < 0.05). No significant difference was observed in the viability of groups cultured with FSH, regardless of the addition of BMP-4, and FSH improved the viability of 50 ng/mL BMP-4 group similar to 10 ng/mL BMP-4 group. The total number of granulosa cells was larger in 10 ng/mL BMP-4 group cultured with FSH than in 50 ng/mL BMP-4 group cultured with FSH on day 8 (P < 0.05). E-2 production decreased from days 8-12, and P-4 production increased throughout IVG culture, regardless of the addition of BMP-4 and FSH (P < 0.05). No significant differences in E-2 production were observed between groups from days 4-8, regardless of whether BMP-4 was added without FSH; however, E-2 production in the group cultured with 50 ng/mL BMP-4 was suppressed by FSH. BMP-4 suppressed E-2 production from days 8-12, regardless of whether FSH was added. The group cultured with 10 ng/mL BMP-4 without FSH showed the lowest P-4 production among all groups for all culture periods. OCGCs that produced mature oocytes tended to secrete more E-2 and less P-4 than OCGCs that produced immature oocytes. In conclusion, until day 8 of the NG culture, P-4 production by OCGCs was suppressed by the addition of 10 ng/mL BMP-4 in the absence of FSH, without inhibiting E-2 production. These conditions appear to mimic growing follicles until day 8 and mimic degenerating follicles from days 8-12 of culture. (C) 2017 Elsevier Inc. All rights reserved.
  • Takahiro Shirozu, Hiroki Iwano, Takatoshi Ogiso, Toshiyuki Suzuki, Ahmed Z Balboula, Hanako Bai, Manabu Kawahara, Koji Kimura, Hitomi Takahashi, Bai Rulan, Sung-Woo Kim, Yojiro Yanagawa, Masashi Nagano, Kazuhiko Imakawa, Masashi Takahashi
    The Journal of reproduction and development 63 3 211 - 220 2017年06月21日 [査読有り][通常論文]
     
    Interferon tau (IFN-τ) is a ruminant-specific type I IFN secreted by a conceptus before its attachment to the uterus. IFN-τ induces the expression of IFN-stimulated genes (ISGs) via the type I IFN receptor (IFNAR), which is composed of IFNAR1 and IFNAR2 subunits in the endometrium. However, expression patterns of IFNARs during the estrous cycle have not been reported. We hypothesized that the response to a type I IFN changes along with IFNARs and the IFN-regulatory factors (IRFs) driving transcription of IFN signal-related genes and modulating a type I IFN signal during the estrous cycle. We investigated the estrous cycle stage-dependent type I IFN induction of ISGs and expression patterns of IFN signal-related genes in bovine endometrial tissues. Endometrial tissue pieces collected from bovine uteri at each estrous stage (early, mid, and late) were cultured with or without recombinant bovine IFN-α or concentrated pregnant uterine flushing (PUF) on day 18 after confirming the presence of a conceptus. IFN-α and PUF each significantly increased the expression of ISGs in endometrial tissues. The induction levels of the typical ISGs (MX1-a and ISG15) were significantly higher at the mid stage and correlated with high expression of IRFs at the mid stage. The immunostaining of IFNARs showed strong fluorescence intensities in luminal and glandular epithelia at the early and mid stages. Collectively, these results suggest that the endometrium exhibits estrous cycle stage-dependent responsiveness to type I IFN that may be associated with the expression of IFNARs and IRFs for pregnancy recognition.
  • Seiji Katagiri, Masaharu Moriyoshi, Yojiro Yanagawa
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 62 5 465 - 470 2016年10月 [査読有り][通常論文]
     
    Normal cows have 2 peaks in endometrial epidermal growth factor (EGF) concentrations on Days 2-4 and 13-14, and the absence of peaks has been linked to reduced fertility in repeat breeder (RB) cows. However, the timing of the peaks (i.e., day of examinations) was estimated for a few cows per cycle day. Therefore, the present study characterized EGF peaks and examined if the absence of peaks in RB cows indicate either peak loss or changed timing. In Study 1, 20 Holstein cows were examined for EGF concentrations between Days 1 and 6 using repeated biopsy of the uterine endometrial tissues. Sixteen cows exhibited increased EGF concentrations for 2-3 days between Days 2 and 5. All 16 cows exhibited increased EGF concentrations on Day 3. In Study 2, 10 cows were examined for EGF concentrations between Days 11 and 16. Increased EGF concentrations for 2-3 days were found in 7 cows between Days 12 and 15. All 7 cows exhibited increased EGF concentrations on Days 13 and 14. In Study 3, 12 RB cows were examined for endometrial EGF concentrations between Days 1 and 6. Four cows exhibited an increase of EGF concentrations on Days 3 and 4, whereas 8 cows (66.7%) exhibited low EGF concentrations throughout the study period. In conclusion, Days 3 and 13-14 are suitable days to examine a cyclic change of endometrial EGF concentrations. Further, low EGF concentrations on Day 3 in RB cows indicated an absence, but not altered timing, of the EGF peak.
  • Chihiro Kanno, Sung-Sik Kang, Yasuyuki Kitade, Yojiro Yanagawa, Yoshiyuki Takahashi, Masashi Nagano
    ZYGOTE 24 4 529 - 536 2016年08月 [査読有り][通常論文]
     
    The present study aimed to develop an objective evaluation procedure to estimate the plasma membrane integrity, acrosomal integrity, and mitochondrial membrane potential of bull spermatozoa simultaneously by flow cytometry. Firstly, we used frozen-thawed semen mixed with 0, 25, 50, 75 or 100% dead spermatozoa. Semen was stained using three staining solutions: SYBR-14, propidium iodide (PI), and phycoerythrin-conjugated peanut agglutinin (PE-PNA), for the evaluation of plasma membrane integrity and acrosomal integrity. Then, characteristics evaluated by flow cytometry and by fluorescence microscopy were compared. Characteristics of spermatozoa (viability and acrosomal integrity) evaluated by flow cytometry and by fluorescence microscopy were found to be similar. Secondly, we attempted to evaluate the plasma membrane integrity, acrosomal integrity, and also mitochondrial membrane potential of spermatozoa by flow cytometry using conventional staining with three dyes (SYBR-14, PI, and PE-PNA) combined with MitoTracker Deep Red (MTDR) staining (quadruple staining). The spermatozoon characteristics evaluated by flow cytometry using quadruple staining were then compared with those of staining using SYBR-14, PI, and PE-PNA and staining using SYBR-14 and MTDR. There were no significant differences in all characteristics (viability, acrosomal integrity, and mitochondrial membrane potential) evaluated by quadruple staining and the other procedures. In conclusion, quadruple staining using SYBR-14, PI, PE-PNA, and MTDR for flow cytometry can be used to evaluate the plasma membrane integrity, acrosomal integrity, and mitochondrial membrane potential of bovine spermatozoa simultaneously.
  • Hiroki Akizawa, Hiroaki Nagatomo, Haruka Odagiri, Nanami Kohri, Nobuhiko Yamauchi, Yojiro Yanagawa, Masashi Nagano, Masashi Takahashi, Manabu Kawahara
    MOLECULAR REPRODUCTION AND DEVELOPMENT 83 6 516 - 525 2016年06月 [査読有り][通常論文]
     
    A common process during preimplantation mammalian development is blastocyst formation, which utilizes signaling through fibroblast growth factor receptor 2 (FGFR2), yet the mechanisms through which FGFR2 signaling affect preimplantation development in bovine embryos remain incompletely understood. Here, we used RNA-interference to investigate the in vitro development, the frequency of blastomere apoptosis, and the mRNA expression of developmental marker genes in FGF receptor 2-knockdown (FGFR2-KD) bovine embryos. A reduction in FGFR2 mRNA did not affect preimplantation development or the frequency of apoptotic blastomeres, but did enhanced proliferation of the inner cell mass in blastocysts (P< 0.05) -which differs from the phenotype reported for bovine embryos using a pharmacological approach (treatment with the pan-FGFR blocker PD173074), but agrees with previous results obtained using mouse embryos. Moreover, the expression of an epiblast marker gene, NANOG, and a primitive endoderm marker gene, GATA6, remained unchanged, whereas the expression of another primitive endoderm marker gene, HNF4A, was significantly reduced in FGFR2-KD embryos. Therefore, FGFR2 signaling appears to be associated with the regulation of inner cell mass development and proliferation during blastocyst formation in cattle.
  • Satomi Kato, Yojiro Yanagawa, Ryota Matsuyama, Masatsugu Suzuki, Chihiro Sugimoto
    PARASITOLOGY RESEARCH 115 4 1463 - 1471 2016年04月 [査読有り][通常論文]
     
    The protozoan Cryptosporidium occurs in a wide range of animal species including many Cervidae species. Fecal samples collected from the Hokkaido sika deer (Cervus nippon yesoensis), a native deer of Hokkaido, in the central, western, and eastern areas of Hokkaido were examined by polymerase chain reaction (PCR) to detect infections with Cryptosporidium and for sequence analyses to reveal the molecular characteristics of the amplified DNA. DNA was extracted from 319 fecal samples and examined with PCR using primers for small-subunit ribosomal RNA (SSU-rRNA), actin, and 70-kDa heat shock protein (HSP70) gene loci. PCR-amplified fragments were sequenced and phylogenetic trees were created. In 319 fecal samples, 25 samples (7.8 %) were positive with SSU-rRNA PCR that were identified as the Cryptosporidium deer genotype. Among Cryptosporidium-positive samples, fawns showed higher prevalence (16.1 %) than yearlings (6.4 %) and adults (4.7 %). The result of Fisher's exact test showed a statistical significance in the prevalence of the Cryptosporidium deer genotype between fawn and other age groups. Sequence analyses with actin and HSP70 gene fragments confirmed the SSU-rRNA result, and there were no sequence diversities observed. The Cryptosporidium deer genotype appears to be the prevalent Cryptosporidium species in the wild sika deer in Hokkaido, Japan.
  • Katsuhisa Nagai, Yojiro Yanagawa, Seiji Katagiri, Masashi Nagano
    BIOMEDICAL RESEARCH-TOKYO 37 1 63 - 71 2016年 [査読有り][通常論文]
     
    To clarify the relationship between ovarian reserve and the developmental competence of bovine oocytes, oocyte-granulosa complexes (OGCs) collected from early antral follicles (<= 1 mm) in ovaries with high (>= 25) and low (<25) antral follicle counts (AFCs) were used. OGCs derived from different AFC groups were cultured for growth followed by maturation, fertilization and blastocyst formation. Viability of OGCs during growth culture was similar between groups; however, OGCs in the high-AFC group had a larger number of granulosa cells than the low-AFC group at 12 days of growth. The proportion of matured oocytes in the high-AFC group was higher than that in the low-AFC group. Mitochondrial activity of oocytes before maturation in the high-AFC group was higher than that in the low-AFC group; however, accumulation of reactive oxygen species was similar between groups. Cleavage rate in the high-AFC group tended to be higher than that in the low-AFC group, although blastocyst development was similar between groups. In conclusion, oocytes derived from ovaries with high AFC have higher maturational ability and fertilizability than those from low AFC. The difference may be caused by high proliferation of granulosa cells from ovaries with high AFC.
  • Weiping Huang, Sung-Sik Kang, Katsuhisa Nagai, Yojiro Yanagawa, Yoshiyuki Takahashi, Masashi Nagano
    REPRODUCTION FERTILITY AND DEVELOPMENT 28 3 349 - 356 2016年 [査読有り][通常論文]
     
    The objective of this study was to investigate the dynamics of mitochondrial activity in in vitro-grown (IVG) bovine oocytes during pre-maturational culture (pre-IVM) and its relationship to their developmental competence upon being subjected to different pre-IVM durations. After 12-day IVG culture, oocytes were cultured for 0, 10 or 20h with 3-isobutyl-1-methylxanthine (IBMX) as pre-IVM. Mitochondrial activity in IVG oocytes after 10h pre-IVM was the highest among all the pre-IVM durations (P<0.05). In addition, cleavage (79.4%) and blastocyst rates (38.9%) of embryos derived from IVG oocytes with 10h pre-IVM were higher than those with 20h pre-IVM (63.0 and 25.8%, respectively; P<0.05) and similar to those of in vivo-grown oocytes (82.7 and 36.7%, respectively). To confirm the developmental ability of IVG oocytes with 10h pre-IVM beyond the blastocyst stage in vivo, embryo transfer was attempted. Transferred embryos developed to the elongated embryonic stage (63.6%, 7/11) in the recipient uterus at Day 16 of oestrus, and a male calf was delivered (50%, 1/2). In conclusion, it was indicated that the mitochondrial activity of bovine IVG oocytes peaked at 10h pre-IVM and was closely correlated with the nuclear maturation and developmental competences of IVG oocytes.
  • Takahiro Shirozu, Keisuke Sasaki, Manabu Kawahara, Yojiro Yanagawa, Masashi Nagano, Nobuhiko Yamauchi, Masashi Takahashi
    The Journal of reproduction and development 62 1 29 - 35 2016年 [査読有り][通常論文]
     
    MX belongs to a family of type I interferon (IFN)-stimulated genes, and the MX protein has antiviral activity. MX has at least two isoforms, known as MX1 and MX2, in mammals. Moreover, bovine MX1 has been found to have alternative splice variants-namely, MX1-a and MX1B. In ruminants, IFN-τ-a type I IFN-is temporarily produced from the conceptus before implantation and induces MX expression in the endometrium. However, the expression dynamics of MX after implantation are not clear. In the present study, we investigated the expression of MX1-a, MX1B and MX2 in the endometrium and placenta before and after implantation along with the expression of IFN-α, type I receptors (IFNAR1 and IFNAR2) and interferon regulatory factors (IRF3 and IRF9). Pregnant uterine samples were divided into five groups according to pregnancy days 14-18, 25-40, 50-70, 80-100, and 130-150. Tissue samples were collected from the intercaruncular endometrium (IC), caruncular endometrium (C) and fetal placenta (P). Although all the MX expressions were significantly higher in the IC and C at days 14-18, presumably caused by embryo-secreted IFN-τ stimulation, their expressions were also detectable in the IC, C and P after implantation. Furthermore, IFN-α expression was significantly higher in the IC. RT-PCR indicated IFNAR1, IFNAR2, IRF3 and IRF9 mRNA in all the tissues during pregnancy. These results suggest that all the MX genes are affected by the type I IFN pathway during pregnancy and are involved in an immune response to protect the mother and fetus.
  • Yinghua Yang, Chihiro Kanno, Weiping Huang, Sung-Sik Kang, Yojiro Yanagawa, Masashi Nagano
    REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY 14 2016年01月 [査読有り][通常論文]
     
    Background: Bone morphogenetic proteins (BMPs) play important regulatory roles during folliculogenesis. Thecaderived BMP-4 may be beneficial to in vitro growth culture of early antral follicle-derived oocyte-granulosa cell complexes (OGCs), which is lacking in theca-derived products. Methods: BMP-4 (0 [control], 10 and 50 ng/mL) was added to growth culture medium. Growth, steroidogenesis and the subsequent developmental competence of OGCs derived from bovine early antral follicles (0.5-1 mm) were examined. Results: At 4, 8 and 12 days of growth culture, progesterone production by granulosa cells was suppressed by the addition of BMP-4 compared to the control (P < 0.05). At 12 days, both the OGC survivability and granulosa cell number in the 50 ng/mL BMP-4 treated group were lower than those of control (48.2 % vs. 67.8 %; 4.96 x 10(4) vs. 8.5 x 10(4) cells; P < 0.05, respectively), while no difference was found between 10 ng/mL and the control. The mean diameters of granulosa cell in the BMP-4 treated groups were smaller than that of the control (P < 0.05). However, the granulosa cell viability, oocyte diameter, oocyte nuclear maturation rate and normal fertilization rate were similar in all of the experimental groups, regardless of the amount of BMP-4 addition (P. 0.05). BMP-4 treated in vitro-grown oocytes showed lower blastocyst rates than untreated ones (P < 0.05). Conclusions: BMP-4 addition during in vitro growth culture suppressed progesterone production and decreased the diameter of granulosa cells, suggesting its effect on steroidogenesis; importantly, it did not affect oocyte growth, nuclear maturation and fertilization. However, BMP-4 impaired subsequent embryonic development, and in higher concentration (50 ng/mL) even compromised OGC viability by suppressing proliferation of granulosa cells.
  • Katsuhisa Nagai, Yojiro Yanagawa, Seiji Katagiri, Masashi Nagano
    ANIMAL REPRODUCTION SCIENCE 163 172 - 178 2015年12月 [査読有り][通常論文]
     
    In this study, to clarify the relationship between ovarian reserve and oocyte quality, cumulus-oocyte complexes (COCs) were collected repeatedly by ovum pick-up (OPU) from cows with high and low antral follicle counts (AFCs) at short (3-4 days) and long (7 days) intervals, and COC morphologies and oocyte fertilizability were examined. The relationship between AFC and follicular growth after OPU was also investigated, Cows showing AFC of >= 30 in at least one OPU session were grouped into the high-AFC group. At a short interval, follicular sizes and COC morphologies were similar between the different AFC groups. However, the normal fertilization rate was higher in the high-AFC group than in the low one, although total penetration rates were similar. At a long interval, the percentage of COCs with poor morphology in the high-AFC group was higher and the normal fertilization rate was lower than in the low one. In the low-AFC group, normal fertilization rates at short and long intervals were similar, and mean follicular size became larger at a long than at a short interval. However, mean follicular sizes at short- and long-interval OPU were similar in the high-AFC group. In conclusion, it is suggested that oocytes derived from cows with high AFC had higher fertilizability than those from cows with low AFC when OPUs were performed at a short (3-4 days) interval. However, oocyte quality in high-AFC cows was impaired by long-interval (7 days) OPU, possibly due to the degradation of follicles. (C) 2015 Elsevier B.V. All rights reserved.
  • Hiroaki Nagatomo, Hiroki Akizawa, Ayari Sada, Yasunori Kishi, Ken-ichi Yamanaka, Tetsuya Takuma, Keisuke Sasaki, Nobuhiko Yamauchi, Yojiro Yanagawa, Masashi Nagano, Tomohiro Kono, Masashi Takahashi, Manabu Kawahara
    JAPANESE JOURNAL OF VETERINARY RESEARCH 63 4 159 - 171 2015年11月 [査読有り][通常論文]
     
    There has been no work on spatiotemporal transcriptomic differences of blastocysts using in vivo- and in vitro-derived, and somatic cell nuclear transfer (SCNT) embryos. Here, we first compared the lineage-differentially transcriptomic profiles of in vivo- and in vitro-derived embryos by microarray analysis using divided into inner cell mass (ICM)-and trophectoderm (TE)-side samples, as well as those derived from SCNT in order to explore lineage-differentially expressed genes that are associated with preimplantation development in cattle. The transcriptomic profiles of the ICM-specific and TE-specific genes were similar between in vitro-derived embryos and in vivo-derived embryos, whereas SCNT embryos exhibited unusual lineage-differentially gene expression regulation at the blastocyst stage. The genes expressed in a spatiotemporal manner between developmentally normal in-vivo derived blastocysts and developmentally abnormal SCNT blastocysts might play critical roles for preimplantation development. Comparing spatial expression dynamics of bovine blastocyst under three different procedures revealed that CHTA was expressed in ICM-side samples of all the embryo types. CIITA is known as the master regulator of major histocompatibility complexes (MHC) class II genes that express in antigen-presenting cells but its biological function in preimplantation embryo is still unknown in mammals. Knockdown of CIITA expression in in vitro-derived embryos did not affect cleavage, but disrupted development of embryos into the blastocyst stage. These findings provide the novel transcriptomic information on blastocyst formation, raising the possibility that immune function-related gene directly plays important roles in bovine preimplantation development.
  • 高江洲昇, 伊藤真輝, 菅原里沙, 柳川洋二郎, 永野昌志
    動物園水族館雑誌 56 2 63  2015年06月25日 [査読無し][通常論文]
  • 中村亮平, 佐藤伸高, 佐橋智弘, 坂東元, 永野昌志, 柳川洋二郎, 松井基純
    動物園水族館雑誌 56 2 55 - 56 2015年06月25日 [査読無し][通常論文]
  • Sung-Sik Kang, Keisuke Koyama, Weiping Huang, Yinghua Yang, Yojiro Yanagawa, Yoshiyuki Takahashi, Masashi Nagano
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 61 2 99 - 105 2015年04月 [査読有り][通常論文]
     
    The present study aimed to establish an efficient system for bovine embryo production by in vitro fertilization (IVF) that can achieve stable normal fertilization and blastocyst developmental rates in any bull without optimization of the sperm concentration in IVF medium. We examined the effects of a PHE mixture (20 mu M D-penicillamine, 10 mu M hypotaurine and 1 mu M epinephrine), theophylline (2.5 mM), and sperm concentration (1, 2 or 5 x 10(6) cells/ml) on fertilization and blastocyst developmental rates. High cleavage rates (78.3 to 92.4%) and blastocyst developmental rates (31.9 to 62.0%) at day 7 were obtained in the presence of PHE and theophylline in IVF medium with a sperm concentration of 2 x 10(6) cells/ml using sperm from 9 bulls. In addition, the synergistic effect of PHE and theophylline on normal fertilization (2 pronuclei) was clarified at 12 h after IVF with a sperm concentration of 1 x 10(6) cells/ml. Moreover, high linearity, high flagellar beat cross frequency, and low amplitude of lateral head of motile sperm were found by computer-assisted spell!' analysis. In conclusion, the combination of the PHE mixture and theophylline synergistically accelerates sperm motility and sperm penetration of bovine oocytes. Theophylline activates sperm motility with increasing intracellular cAMP. However, PHE prevents an excessive increase of cAMP and maintains speiln motility without hyperactivation. When the combination of PHE and theophylline is added to IVF medium at a sperm concentration of 2 x 10(6) cells/ml, we can achieve stable normal fertilization and blastocyst development in any bull.
  • 泌乳初期乳牛における濃厚飼料中デンプン源の高消化繊維への代替がエネルギーバランスおよび排卵機能回復に及ぼす影響(Effect of substitution of highly-digestible fiber of beet pulp for corn grain starch in concentrate on energy balance and recovery of ovulatory function in early lactating dairy cows)
    Min Bo, 正木 智之, 永野 昌志, 柳川 洋二郎, 三谷 朋弘, 上田 宏一郎, 近藤 誠司
    北海道畜産草地学会報 3 45 - 53 北海道畜産草地学会 2015年03月 [査読無し][通常論文]
  • 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 2015年02月 [査読有り][通常論文]
     
    Generally, sika deer conceive a single fetus, but approximately 80% of pregnant females have two corpora lutea (CLs). The function of the accessory CL (ACL) is unknown; moreover, the process of ACL formation is unclear, and understanding this is necessary to know its role. To elucidate the process of ACL formation, the ovarian dynamics of six adult Hokkaido sika deer females were examined ultrasonographically together with peripheral estradiol-17 beta and progesterone concentrations. ACLs formed in three females that conceived at the first estrus of the breeding season, but not in those females that conceived at the second estrus. After copulation, postconception ovulation of the dominant follicle of the first wave is induced by an increase in estradiol-17 beta, which leads to formation of an ACL. A relatively low concentration of progesterone after the first estrus of the breeding season is considered to be responsible for the increase in estradiol-17 beta after copulation.
  • 板橋知子, 片桐成二, 柳川洋二郎, 佐藤秀俊, 及川俊徳
    宮城県獣医師会会報 68 1 13‐15  2015年01月 [査読無し][通常論文]
  • 板橋 知子, 片桐 成二, 柳川 洋二郎, 及川 俊徳
    東北農業研究 67 75 - 76 [東北農業試験研究協議会] 2014年12月 [査読無し][通常論文]
     
    乳牛では受胎率の低下が問題となっており、その原因の一つとして子宮内膜における上皮成長因子(EGF)の発現異常が高産乳牛やリピートブリーダーで確認されている。正常牛の子宮内膜EGF濃度は、発情2~4日目および13~14日目に上昇し二峰性のピークを示すが、リピートブリーダー牛ではこのピークが低下し、周期的変動が消失することが報告されている。最近、牛精漿をリピートブリーダー牛の膣内に注入することによって子宮内膜のEGF発現が正常化し、受胎性が向上したとの報告がある。そこで今回は、場内で繋養している黒毛和種種雄牛の精漿をホルスタイン種リピートブリーダー牛に投与し、その効果について検討した。
  • Kei Fukuda, Kenji Ichiyanagi, Masashi Nagano, Yojiro Yanagawa, Noboru Takaesu, Hiroo Imai, Hiroyuki Sasaki
    GENES & GENETIC SYSTEMS 89 6 309 - 309 2014年12月 [査読有り][通常論文]
  • Kuerban Tulake, Yojiro Yanagawa, Yoshiyuki Takahashi, Seiji Katagiri, Shogo Higaki, Keisuke Koyama, Xuguang Wang, Heping Li
    JAPANESE JOURNAL OF VETERINARY RESEARCH 62 4 187 - 192 2014年11月 [査読有り][通常論文]
     
    The effects of different preservation conditions (temperature 20-25 or 10-15 degrees C; duration 12 or 24 h) for ovaries of Cervus nippon yesoensis on in vitro maturation of oocytes were examined. When ovaries were kept for 12 h at 20-25 degrees C, maturation rate of oocytes was highest (71%); however, it declined when the preservation time was extended to 24 h (31%). When the preservation temperature decreased to 10-15 degrees C, the maturation rate after 12 h preservation decreased (51%) but it remained in same level even though preservation time is prolonged to 24 h (55%).
  • Weiping Huang, Sung-Sik Kang, Yojiro Yanagawa, Yinghua Yang, Yoshiyuki Takahashi, Masashi Nagano
    JAPANESE JOURNAL OF VETERINARY RESEARCH 62 3 135 - 141 2014年08月 [査読有り][通常論文]
     
    The effects of in vitro-growth (IVG) culture duration (12 and 14 days) on the fertilizability and the developmental ability of IVG oocytes matured with pre-maturational culture, and on the proliferation of cells surrounding oocytes during IVG culture were examined. The fertilization and cleavage rates of 12- and 14-day IVG oocytes were similar; however, 14-day IVG oocytes showed lower blastocyst development rate than 12-day IVG oocytes. In addition, the number of cells surrounding oocytes increased until 12 days of IVG, but decreased at 14 days. The results indicated that the extension of IVG period beyond 12 days impaired the proliferation of cells surrounding oocytes, leading to the decrease of developmental ability but not fertilizability of 14-day IVG oocytes.
  • Keisuke Koyama, Sung-Sik Kang, Weiping Huang, Yojiro Yanagawa, Yoshiyuki Takahashi, Masashi Nagano
    JOURNAL OF VETERINARY MEDICAL SCIENCE 76 5 653 - 659 2014年05月 [査読有り][通常論文]
     
    The objective of this research was to estimate the optimal timing for fertilization to achieve proper embryonic development of in vitro-matured bovine oocytes. First, cumulus-oocyte complexes were subjected to in vitro maturation (IVM) for 14-22 hr. The timing when 50% of oocytes reached metaphase II stage was estimated to be 17.5 hr after IVM start. Next, using oocytes subjected to IVM for 12-30 hr, sperm penetration was examined after 4-18 hr of in vitro fertilization (IVF). A significant negative correlation between IVM duration and the timing when 50% of oocytes were penetrated by sperm after IVF start was observed (P<0.01). Finally, oocytes subjected to 12-30 hr of IVM were inseminated and cultured for 6 days to examine embryonic development. In the group with 22 hr of IVM, the percentages of cleaved embryos and blastocysts were the highest values in all groups. According to the regression equation describing the time from nuclear maturation to sperm penetration (x) and the percentage of blastocysts (y) (y=7.23 x -0.297x(2), P<0.01), the blastocyst rate peaked when sperm penetration occurred at 12.2 hr after achieving nuclear maturation. In conclusion, under the present IVM/IVF conditions, it was estimated that oocytes acquired their highest developmental competence at about 30 hr after IVM start, and thus, the optimal IVM duration was calculated to be about 21 hr.
  • Keisuke Koyama, Sung-Sik Kang, Weiping Huang, Yojiro Yanagawa, Yoshiyuki Takahashi, Masashi Nagano
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 60 2 136 - 142 2014年04月 [査読有り][通常論文]
     
    The objective of this research was to clarify the aging-related changes in in vitro-matured bovine oocytes. Firstly, we examined the fertilization and embryonic development of bovine oocytes after 22 and 30-34 h of in vitro maturation (IVM). The oocytes after 30-34 h of IVM (penetrated by sperm at around 40 h after starting IVM) showed a lower developmental rate to blastocysts (P<0.01), although normal fertilization rates were similar regardless of IVM duration. In the next experiment, reactive oxygen species (ROS), mitochondrial activity and ATP content in oocytes after 20, 30 and 40 h of IVM were examined. The lowest level of ROS was found in the group subjected to 30 h of IVM. The mitochondrial activity and ATP content in the group subjected to 40 h of IVM were higher than in the group subjected to 20 h of IVM (P<0.01), and those in the group subjected to 30 h of IVM showed intermediate values. Thereafter, the mitochondrial activities at 3 days after in vitro fertilization in embryos derived from the oocytes subjected to 22 and 34 h of IVM were evaluated. In the group subjected to 34 h of IVM, high-polarized mitochondria were frequently observed at the periphery of blastomeres. The present results suggest that high mitochondrial activity observed in oocytes after prolonged IVM culture and localization of high-polarized mitochondria at the periphery of blastomeres during early embryonic development may be associated with the low developmental competence in aged bovine oocytes.
  • 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.
  • Kang SS, Ofuji S, Imai K, Huang W, Koyama K, Yanagawa Y, Takahashi Y, Nagano M
    Zygote (Cambridge, England) 23 3 1 - 4 2014年03月 [査読有り][通常論文]
  • Kohei Kobayashi, Makoto Asano, Yojiro Yanagawa, Singo Haneda, Motozumi Matsui
    MAMMAL STUDY 39 1 59 - 64 2014年03月 [査読有り][通常論文]
  • Weiping Huang, Masashi Nagano, Sung-Sik Kang, Yojiro Yanagawa, Yoshiyuki Takahashi
    JOURNAL OF REPRODUCTION AND DEVELOPMENT 60 1 9 - 13 2014年02月 [査読有り][通常論文]
     
    The objective of this study was to clarify the effects of prematurational culture (pre-IVM) supplemented with 3-isobutyl-1-methylxanthine (IBMX) on nuclear and cytoplasmic maturation of in vitro-grown bovine oocytes. In experiment 1, oocytes (95 pm in diameter) derived from early antral follicles (0.5-1 mm in diameter) were cultured for 12 days for in vitro growth (IVG). IVG oocytes with a normal appearance were subjected to examinations of diameter and chromatin structure in the germinal vesicle (GV) before IVM. In addition, percentages of metaphase II (M II) were examined after IVM. Regardless of pre-IVM, the mean diameters of IVG oocytes were about 115 p,m. The proportions of GV3 (50.0%) and M II stages (80.1%) of IVG oocytes with pre-IVM were higher than those without pre-IVM (28.0 and 49.4%, respectively). In experiment 2, the fertilizability and developmental competence of IVG oocytes were examined. Regardless of pre-IVM, the normal fertilization rates of IVG oocytes were similar (around 70%) but were lower than that of in vivo-grown oocytes (88.0%). Cleavage and blastocyst rates of IVG oocytes with pre-IVM (63.0 and 26.1%, respectively) were higher than those without pre-IVM (45.8 and 12.7%, respectively). The blastocyst rate based on cleaved IVG oocytes with pre-IVM (41.7%) was similar to that of in vivo-grown oocytes (48.7%), although the cleavage rate of PIG oocytes with pre-IVM was lower than that of in vivo-grown oocytes. In conclusion, pre-IVM with IBMX improved the maturational and developmental competences of IVG oocytes, probably due to promotion of their chromatin transition and synchronization of meiotic progression.
  • 柳川洋二郎
    獣医畜産新報 1110 33 - 35 2014年01月01日 [査読無し][通常論文]
  • 栁川 洋二郎
    獣医畜産新報 67 1 33 - 35 文永堂出版 2014年01月 [査読無し][通常論文]
  • Masashi Nagano, Sung-Sik Kang, Keisuke Koyama, Weiping Huang, Yojiro Yanagawa, Yoshiyuki Takahashi
    The Japanese journal of veterinary research 61 4 149 - 54 2013年11月 [査読有り][通常論文]
     
    As a preliminary study for the development of individual in vitro maturation (IVM) culture of bovine oocytes, a multi-well (MW) plate was used. Maturation, fertilization and development to blastocysts were examined and compared with those of IVM oocytes cultured in 50-microl droplets in groups and in 10-microl droplets individually. The maturation rates were similar in all experimental groups. Normal fertilization rates in MW and 50-microl droplets were similar, but lower in 10-microl droplets (p < 0.01). The blastocyst rate in 10-microl droplets tended to be lower than those in MW (p = 0.15) and 50-microl droplets (p = 0.19). These results indicate that an IVM system using MW supports the acquisition of developmental competence by bovine oocytes the same as conventional group IVM culture.
  • Huang W, Nagano M, Kang SS, Yanagawa Y, Takahashi Y
    Theriogenology 80 7 793 - 799 7 2013年10月 [査読有り][通常論文]
     
    Bovine ovaries offer a large pool of oocytes that could be used for in vitro production of embryos of genetically valuable animals. The effects of in vitro growth (IVG) culture duration (10, 12, and 14 days) on the viability and growth of bovine oocytes derived from early antral follicles (0.5-1 mm diameter) in this study. In addition, the effect of pre-IVM culture with phosphodiesterase inhibitor (3-isobutyl-1-methylxanthine) on nuclear maturation of IVG oocytes was also evaluated. In experiment 1, oocyte viability observed after 10 or 12 days of IVG culture was greater (P < 0.05) than that observed after 14 days of culture. Oocyte diameters and proportions of oocytes at metaphase II stage were greater (P < 0.05) when 12 or 14 days of IVG culture where used when compared with 10 days culture. In addition, the proportion of oocytes at metaphase II stage was greater (P < 0.05) when pre-IVM culture was performed for oocytes derived from 12 and 14 days of IVG culture. When 12 and 14 days of IVG culture followed by pre-IVM culture were compared in experiment 2, cumulus cell membrane integrity was greater (P < 0.05) after 12 days. Blastocyst production rate for oocytes obtained after 12 days of IVG culture (24.5%) was greater (P < 0.05) than for oocytes obtained after 14 days (9.9%). In conclusion, 12 days IVG followed by pre-IVM culture was considered the optimal processing system for bovine oocytes derived from early antral follicles when oocyte viability, diameter, maturation, and development competences were considered. (C) 2013 Elsevier Inc. All rights reserved.
  • Daisuke Fukui, Masashi Nagano, Ryohei Nakamura, Gen Bando, Shinichi Nakata, Masao Kosuge, Hideyuki Sakamoto, Motozumi Matsui, Yojiro Yanagawa, Yoshiyuki Takahashi
    Journal of Reproduction and Development 59 5 491 - 495 2013年 [査読有り][通常論文]
     
    Artificial insemination (AI) can help to avoid inbreeding and genetic degeneration for sustaining genetically healthy populations of endangered species in captivity. Collection of a sufficient quantity of viable sperm is an essential first step in the AI process. In the present study, we examined the effects of frequent electroejaculation on semen characteristics in a Siberian tiger. We collected semen in all 17 trials during 6 breeding seasons (6 years). The mean number of sperm and the percentage of motile sperm were 294.3 ± 250.2×106/ejaculate and 82.4 ± 11.4%, respectively. The number of motile sperm tended to increase during frequent electroejaculation in the same breeding season. Semen collection by electroejaculation can be performed effectively up to the fourth sequential ejaculate, which contained the most sperm in the study. In conclusion, frequent collection of sperm by electroejaculation from tigers may be effective for collection of a large number of motile sperm. © 2013 by the Society for Reproduction and Development.
  • 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 2009年04月 [査読有り][通常論文]
     
    In sika deer, the normal method of estimating fetal age, based on fetal weight, is not applicable during the early pregnancy period. The objective of the present study was to describe the growth and development of sika deer fetuses and to establish a method for fetal age estimation during early pregnancy using ultrasonography. Five captive female Hokkaido sika deer (Cervus nippon yesoensis) were observed for estrus and mated (day 0) with an intact male. At two- or three-day intervals, fetuses were observed by rectal ultrasonographic scans until 59-61 days of gestation. The straight crown-rump length (SCRL), curved crown-rump length (CCRL), head length (HL), trunk depth (TD) and heart rate (HR) of the fetuses were measured. Linear regression equations were computed for each measurement together with fetal age. Analyses were conducted after transformation to a natural logarithm for SCRL and CCRL. All equations were significant (P<0.001), with SCRL becoming measurable earlier (day 20) than the others and yielding the best correlation (Days = -2.08+14.15 LnX: X=SCRL, Ln=natural logarithm). Therefore, we concluded that a precise estimation of fetal age in early gestation is best performed using SCRL measurements.
  • Yojiro Yanagawa, Yukiko Matsuura, Masatsugu Suzuki, Seiji Katagiri, Toshio Tsubota
    JAPANESE JOURNAL OF VETERINARY RESEARCH 56 3 139 - 149 2008年11月 [査読有り][通常論文]
     
    Information on steroid hormone receptor distribution in the uterus is essential to understand the roles of their ligands in pregnancy. This study examined the spatio-temporal localization of estrogen receptor alpha (ER alpha) and progesterone receptor (PR) in the uterus of sika deer (Cervus nippon) to determine the estrogen and progesterone action site during pregnancy. Ovaries and uteri were collected from 21 pregnant sika deer with single fetus and two corpora lutea, ranging from Day 20 to Day 207 of pregnancy. In addition, genital organs were also collected from three sika deer whose gestational status was unknown: one female had only one developing corpus luteum: <= Day 4 (metestrus) and two females had two corpora lutea, one of which was at the developing stage equivalent to diestrus or early pregnancy: > Day 7 (diestrus). Staining of ER(x and PR was clear in all cell types during metestrus. During diestrus, the presence of ERa was also clear in deep glandular epithelium, stroma and myometrium., whereas it was suppressed in luminal epithelium and shallow glandular epithelium. Staining of PR was suppressed in luminal epithelium but was detectable in other cell types. Staining of ERa in all cell types and PR in luminal epithelium and glandular epithelium became undetectable by Day 28. PR was presented in stroma and myometrium. throughout pregnancy. The distribution pattern of ERa and PR was different during diestrus from that in a ruminant. This could be attributed to estrogen secretion from the maturing and ovulating follicles in the presence of developed corpus luteum.
  • Effect of a tranquilizer on stress control in birds under restraint
    Yanagawa Y, Suzuki K
    Biosphere Conservation 6 2 55 - 59 2004年 [査読有り][通常論文]
  • Astaxanthin improves the developmental competence of in vitro grown oocytes and modifies the steroidogenesis of granulosa cells derived from bovine early antral follicles
    柳川 洋二郎
    Reproduction Fertility and Development [査読有り][通常論文]

書籍

  • 増補版野生動物管理 -理論と技術-
    柳川 洋二郎 (担当:共著範囲:第22章 繁殖状態評価法)
    文永堂出版 2016年 311-327
  • 動物園動物管理学
    柳川 洋二郎 (担当:共著範囲:第34章 余剰動物対策のための避妊)
    文永堂出版 2014年
  • 野生動物管理
    柳川 洋二郎 (担当:共著範囲:第20章 繁殖状態評価法)
    文永堂出版 2012年05月

講演・口頭発表等

受賞

  • 2018年09月 日本獣医学会繁殖分科会 日本獣医繁殖学・優秀発表賞
     クラスター解析の精子受胎性評価への応用: 性選別および通常凍結精液中の精子運動性サブポピュレーション構成の比較 
    受賞者: 菅野智裕;栁川洋二郎;片桐成二;永野昌志
  • 2018年09月 日本哺乳類学会 優秀ポスター賞
     オスヒグマ(Ursus arctos)は背擦り行動により繁殖に関する情報を伝達しているのか? ヒグマ背部脂腺と精巣機能の関係 
    受賞者: 冨安洵平;林優季;栁川洋二郎;松本直也;坂元秀行;佐々木和義;佐藤喜和;羽田真悟;松井基純
  • 2018年09月 日本野生動物医学会 奨励賞
     野生動物における人工授精技術の確立に向けた卵巣動態解析および精液採取・授精技術開発 
    受賞者: 柳川 洋二郎
  • 2017年09月 日本獣医学会繁殖分科会 日本獣医繁殖学・優秀発表賞
     牛卵巣内胞状卵胞数と初期胞状卵胞由来卵子‐顆粒層細胞複合体の顆粒層細胞増殖能および卵子発生能の関連性 
    受賞者: 坂口謙一郎;谷田孝志;楊応華;菅野智裕;永井克尚;Mohammed A. Abdel-Ghani;柳川洋二郎;片桐成二;永野昌志
  • 2016年09月 日本獣医学会繁殖分科会 日本獣医繁殖学・優秀発表賞
     牛精液の射出順序が精子運動性サブポピュレーション構成に与える影響 
    受賞者: 菅野智裕;柳川洋二郎;片桐成二;髙橋芳幸;永野昌志
  • 2016年06月 日本獣医学会繁殖分科会 繁殖学・優秀発表賞
     牛卵巣内胞状卵胞数と初期胞状卵胞由来卵子顆粒層細胞複合体の性ステロイドホルモン産生能の関係 
    受賞者: 柳川 洋二郎
  • 2014年09月 日本獣医学会繁殖分科会 日本獣医繁殖学・優秀発表賞
     経産豚の子宮内膜における人工授精後のサイトカイン発現変化と受胎性の関係 
    受賞者: 奥山みなみ;社浦宗徳;柳川洋二郎;森好政晴;片桐成二
  • 2014年06月 Korean Society of Embryo Transfer 2014 Symposium of the Korean Society of Embryo Transfer Best oral presentation award
     The sperm penetration rate and embryo developmental kinetics of embryos fertilized with sex-sorted sperm in bovine 
    受賞者: 柳川 洋二郎

教育活動情報

主要な担当授業

  • 先端獣医科学特論A 動物生殖医学特論
    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
  • 繁殖生理学総論
    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 : 雌雄生殖器、配偶子、ホルモン、生殖周期、交配、受精、妊娠、分娩、産褥
  • 先端獣医科学特論A 国際獣医科学特論:臨床獣医学
    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
  • 繁殖病態学
    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 : 人工繁殖技術、生殖機能調節の実際、伴侶動物
  • 獣医科学基礎科目 臨床疾病学特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学院
  • 生産獣医療学実習
    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 : 生産病、ハードヘルス、ボディコンディションスコア、牛群検定(乳検)、代謝プロファイルテスト
  • 先端獣医科学科目 動物生殖医学特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学院
  • 国際交流Ⅱ
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 国際本部
    キーワード : wildlife, veterinary medicine, conservation medicine, Hokkaido
  • 総合専門臨床特論
    開講年度 : 2018年
    課程区分 : 博士後期課程
    開講学部 : 獣医学院
  • 繁殖学実習
    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 : 発情、人工授精、受精卵移植、妊娠、分娩
  • 獣医臨床総合実習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部
  • 獣医専門科診療実習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部
  • 生産獣医療学実習
    開講年度 : 2018年
    課程区分 : 学士課程
    開講学部 : 獣医学部
  • 産業動物獣医療実習
    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

  • 2016年04月 - 現在   日本野生動物医学会   広報委員
  • 2013年04月 - 現在   日本野生動物医学会   幹事
  • 2016年08月 - 2018年07月   日本獣医学会繁殖分科会   会計


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