Researcher basic information

• 博士(獣医学), 北海道大学

• https://researchmap.jp/yojiro?lang=en

• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201201037522067223

• 201201037522067223

• 臨床繁殖
• 動物園動物
• 繁殖学
• 野生動物

• Life Science, Veterinary medical science

• Bachelor's degree program, School of Veterinary Medicine
• Doctoral (PhD) degree program, Graduate School of Veterinary Medicine

Research activity information

• Sep. 2025, 日本獣医学会, 日本獣医学会学術集会 優秀発表賞
  A Toll-like receptor 4-mediated regulation of EGF production in the bovine uterine cell by palmitic acid
  Mwandabantu M.;Sakaguchi K.;Saito M.;Nunez HJC;Tadeo R.;Tanida T.;Yanagawa Y.;Katagiri S.
• Jan. 2024, tTe international embryo technology society, Peter W. Farin Trainee Travel Scholarship Award
  An active site of osteopontin restoring the endometrial epidermal growh factor profile and fertility in repeat breeder dairy cows
  Tanida T.;Tagami T.;Yanagawa Y.;Katagiri S.
• Sep. 2023, 日本繁殖生物学会, 日本繁殖生物学会優秀発表賞
  ウシ胚内部細胞塊における転写共役因子YAP1の細胞内局材とその意義
  齋藤隼;西山洸司;柳川洋二郎;唄花子;高橋昌志;川原学
• Sep. 2023, 日本獣医学会, 日本獣医学会学術集会 優秀発表賞
  牛の体内における卵巣内温度に基づいた培養温度が初期胞状卵胞に由来する卵子の体外発育および発生能に及ぼす影響
  河野光平;坂口謙一郎;栁川洋二郎;片桐成二
• Mar. 2023, 日本生態学会, 最優秀賞
  血液を用いてヒグマの年齢を推定する ～DNAメチル化率を指標として～
  中村汐里;山﨑淳平;松本直也;伊藤英之;村山美穂;斉惠元;木下こづえ;山中正実;柳川洋二郎;佐鹿万里子;坪田敏男;下鶴倫人
• Sep. 2022, 日本獣医学会, 第165回 日本獣医学会 学術集会優秀発表賞
  ヒグマにおける血液DNAのメチル化率を指標とした年齢推定の試み
  中村汐里、山﨑淳平、松本直也、伊藤英之、村山美穂、斉惠元、木下こづえ、山中正実、柳川洋二郎、佐鹿万里子、坪田敏男、下鶴倫人
• Sep. 2022, 日本獣医学会, 第165回 日本獣医学会学術集会 優秀発表賞
  ステロイドホルモンおよびその抱合体化物の血中組成における動物種差
  163. 伊藤愛真、近藤充希、池中良徳、田中亜紀、下鶴倫人、佐鹿万里子、柳川洋二郎、笠松雅彦、角川雅俊、中山翔太、石塚真由美
• Jan. 2021, International Embryo Technology Society, Peter W. Farin Trainee (Travel) Scholarship Award 2021
  The effects of heat exposure on the growth and developmental competence of oocytes derived from early antral follicles in dairy cows
  Kawano K;Sakaguchi K;Furukawa E;Chelenga M;Yanagawa Y;Katagiri S
• Sep. 2020, 日本獣医学会繁殖分科会, 日本獣医繁殖学・優秀発表賞
  牛卵巣内の主席卵胞と黄体の存在が初期胞状卵胞由来卵子の核成熟能と顆粒層細胞の性ステロイドホルモン産生能に及ぼす影響
  坂口謙一郎、河野光平、栁川洋二郎、片桐成二、永野昌志
• Oct. 2018, Asian Society of Conservation Medicine, The Excellent Oral Presentation
  Monitoring of follicular dynamics using ultrasonography and ovulation induction by GnRH in captive brown bear (Ursus arctos)
  Torii Y;Matsumoto N;Sakamoto H;Nagano M;Katagiri S;Yanagawa Y
• Sep. 2018, 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
  菅野智裕;栁川洋二郎;片桐成二;永野昌志
• Sep. 2018, 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
  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
• Sep. 2018, 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
  柳川 洋二郎
• Sep. 2017, 日本獣医学会繁殖分科会, 日本獣医繁殖学・優秀発表賞
  黒毛和種リピートブリーダー牛の子宮内膜上皮成長因子発現異常に対する治療への抵抗性と肥満の関係
  谷田孝志;坂口謙一郎;菅野智裕;池田侑樹;田嶋彩野;柳川洋二郎;永野昌志;片桐成二
• Sep. 2017, 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
  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
• Sep. 2016, 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
  菅野智裕;柳川洋二郎;片桐成二;髙橋芳幸;永野昌志
• Jun. 2016, 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
  坂口謙一郎、谷田孝志、永井克尚、楊応華、柳川洋二郎、片桐成二、永野昌志
• Sep. 2014, 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
  奥山みなみ;社浦宗徳;柳川洋二郎;森好政晴;片桐成二
• Jun. 2014, 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
  Kang SS;Takahashi Y;Yanagawa Y;Nagano M

• Effects of osteopontin treatment alone and in combination with hormonal therapy on endometrial epidermal growth factor concentration and fertility at the first insemination after calving in dairy cows
  Taiwo Kamardeen Bello; Takashi Tanida; Takayoshi Tagami; Yojiro Yanagawa; Seiji Katagiri
  Theriogenology, 254, 117812, 117812, Elsevier BV, Apr. 2026
  Scientific journal
• Relationship Between Testosterone and Movement Patterns in Male Asian Black Bear ( Ursus thibetanus )
  Naoki Takekoshi; Jumpei Tomiyasu; Yojiro Yanagawa; Naoki Ohnishi; Tomoko Naganuma; Seung‐Yun Baek; Miu Itoh; Xin Luo; Tatsuhito Nishiwaki; Chinatsu Kozakai; Shinsuke Koike; Koji Yamazaki
  Ecology and Evolution, 16, 1, Wiley, 11 Jan. 2026
  Scientific journal, ABSTRACT
  
  In male mammals, reproduction and reproductive behavior are strongly influenced by testosterone. While some species exhibit roaming behavior to encounter receptive females and show consorting behavior with females, the relationship between sex hormone and those behaviors remains unclear. To clarify testosterone's influence on behavior, we examined fecal testosterone metabolites (FTM) and behaviors in male Asian black bears ( Ursus thibetanus ) using collars equipped with GPS transmitters, activity sensors, and animal‐borne cameras. We assessed four behavioral variables (daily movement speed, net movement distance, turning angle, activity level) and mating behavior in five males over a cumulative 8 years. Fresh fecal samples, collected at GPS locations of collared individuals, were analyzed for FTM. In total, 111 feces were collected in 2022–2023 across 58 locations. The FTM values and the four behavioral variables were compared between the breeding (May–July) and post‐breeding season (August–November) using the Brunner–Munzel test. Overall, FTM were higher, while movement speed and activity levels were lower during the breeding season than in the post‐breeding season. These results suggest that some males may engage in consorting associated with elevated testosterone. We further examined the relationships between FTM and the four behavioral variables using Spearman's correlation tests. The correlation between FTM and behaviors varied among males. For example, the relationship between FTM and net movement distance was negative in two males but positive in three males. These interindividual differences in testosterone–behavior correlations were possibly the result of incomplete sampling during mating and consorting, as well as variation in breeding strategies. The negative relationships may indicate mate guarding or consorting, whereas positive relationships may reflect roaming. Our results suggested that the behavior of male Asian black bears may be influenced by increased testosterone, and monitoring testosterone allows us to gain insights into male bear behavior.
• Less-invasive age estimation using hair based on DNA methylation in brown bears
  Shiori Nakamura; Jumpei Yamazaki; Naoya Matsumoto; Kyogo Hagino; Hideyuki Sakamoto; Masami Yamanaka; Masanao Nakanishi; Mina Jimbo; Yojiro Yanagawa; Hideyuki Ito; Toshio Tsubota; Michito Shimozuru
  Scientific Reports, 15, 1, Springer Science and Business Media LLC, 29 Dec. 2025
  Scientific journal
• Epigenetic Clock in Bears: A Simple Cost-Effective Blood DNA Methylation-Based Age Estimation Method Applicable to Multiple Bear Species.
  Michito Shimozuru; Shiori Nakamura; Jumpei Yamazaki; Yojiro Yanagawa; Hiroo Tamatani; Misako Kuroe; Koji Yamazaki; Shinsuke Koike; Yusuke Goto; Tomoko Naganuma; Kahoko Tochigi; Akino Inagaki; Naoki Takekoshi; Seungyun Baek; Nobutaka Sato; Yusuke Honda; Toshio Tsubota; Hideyuki Ito
  Ecology and evolution, 15, 5, e71424, May 2025, [International Magazine]
  English, Scientific journal, Age is an essential factor to understand the life history and demographic parameters of wildlife. Previously, we established an age estimation method for brown bears based on blood DNA methylation level. In this study, we first applied the brown bear-specific age estimation model to other bear species, including Asian black, polar, sun, and Andean bears. Using blood DNA, we performed bisulfite pyrosequencing to determine the methylation levels at four cytosine-phosphate-guanine (CpG) sites adjacent to a single gene, SLC12A5. The best model specific to brown bears estimated their ages with satisfactory accuracy, with mean absolute error (MAE) of 1.5, 2.1, 2.2, and 0.4 years for Asian black (52 samples from 16 captive and 36 wild bears), polar (27 samples from 21 captive bears), sun bears (11 samples from 8 captive bears), and Andean bears (one captive bear), respectively. Then, we established an Asian black bear-specific age estimation model and a common age estimation model applicable for other bear species (i.e., a pan-bear model) using the methylation levels of the four CpG sites. The best model specific to Asian black bears had high accuracy with MAE of 1.1 after leave-one-out cross-validation (LOOCV). In addition, the best pan-bear model achieved accuracy with MAE of 1.3, 1.2, 2.1, and 2.2 years after LOOCV for brown, Asian black, polar, and sun bears, respectively. The results suggested that the pan-bear age estimation model using the aging marker (CpG sites adjacent to SLC12A5) is a simple, highly accurate, and cost-effective tool that is applicable to Ursidae.
• Association Between Back Scent Gland Development and Reproductive Status in Male Brown Bears (Ursus arctos)
  Jumpei Tomiyasu; Naoya Matsumoto; Katsushima Hinako; Asuka Nishijima; Kyogo Hagino; Hideyuki Sakamoto; Yojiro Yanagawa
  Journal of Experimental Zoology Part A: Ecological and Integrative Physiology, Wiley, 24 Mar. 2025
  Scientific journal, ABSTRACT
  
  Cutaneous scent glands secrete chemical signals for communication, a significant portion of which is to convey information about male reproductive status. This might be particularly important to animals with intraspecific variation in male reproductive activity, such as bears. Male brown bears mark trees with their scent secreted from back apocrine and sebaceous glands during the breeding season and thus might convey information about reproductive status. Therefore, we speculated that the development of scent glands in the back reflects reproductive performance. We investigated the effects of reproductive status on the development of scent glands in the back using contraception and explored relationships between reproductive parameters (testosterone levels, testis size, and spermatogenic scores) and the size of skin glands in the backs of intact male brown bears. During the breeding season, we sampled back and rump (control) skin, sperms by urethral catheterization, and blood under anesthesia from four male bears that were vaccinated with the contraceptive gonadotropin hormone‐releasing hormone (GnRH) vaccine and five others that were not (controls). The back sebaceous and apocrine glands were significantly smaller in bears vaccinated with than without GnRH vaccine, suggesting that these glands are associated with reproductive status. Testosterone levels were significantly and positively associated with the size of sebaceous glands, whereas none of the reproductive parameters were associated with the size of either sebaceous or apocrine glands. Mating opportunities increase testosterone production. The positive association between testosterone and sebaceous glands might mean that sebaceous glands in the back can secrete chemicals on demand for reproduction.
• In vivo ovarian temperature promotes the in vitro growth and developmental competence of oocytes derived from bovine early antral follicles
  Kohei Kawano; Kenichiro Sakaguchi; Yojiro Yanagawa; Seiji Katagiri
  Theriogenology, 117371, 117371, Elsevier BV, Feb. 2025
  Scientific journal
• Exploring the Influence of Heat Stress on Gene Expression in Bovine Myeloid Cells In Vitro
  Hanako Bai; Yua Saito; Hiroki Nakajima; Manabu Kawahara; Yojiro Yanagawa; Masashi Takahashi; Kazuo Miyazaki
  Animal Science Journal, 96, 1, Wiley, Jan. 2025
  Scientific journal, ABSTRACT
  
  Heat stress affects cattle production and suppresses immune function in cows. However, the effects of heat stress on myeloid lineage cells are unexplored. In this study, we aimed to identify genes affected by heat stress. We established three immortalized bovine myeloid cell lines and performed RNA sequencing to investigate their potential target genes. We identified 765 differentially expressed genes. We performed real‐time polymerase chain reaction analysis on the top three upregulated genes, C‐C motif chemokine ligand 17, CD1e molecule, and beta‐carotene oxygenase 2, as well as the downregulated genes, RNA‐binding motif protein 3, HD domain containing 2, and solute carrier family 25 member 12, to validate the RNA sequencing results. Our analysis revealed that heat stress affected 14 Gene Ontology processes and 13 molecular pathways. Our study provides a comprehensive gene expression profile of bovine myeloid cells under heat‐stress conditions.
• Effects of heat stress on gene expression associated with antioxidant capacity of bovine early antral follicles
  Kohei KAWANO; Kenichiro SAKAGUCHI; Eri FURUKAWA; Nattapong NINPETCH; Yojiro YANAGAWA; Seiji KATAGIRI
  Journal of Veterinary Medical Science, Japanese Society of Veterinary Science, 2025
  Scientific journal
• Identification of an osteopontin structural element for the restoration of a normal endometrial epidermal growth factor (EGF) profile determined by the EGF concentration on day 3 of estrous cycle and pregnancy outcome in repeat breeder dairy cows.
  Takashi Tanida; Takayoshi Tagami; Yojiro Yanagawa; Seiji Katagiri
  Theriogenology, 231, 171, 181, 01 Jan. 2025, [International Magazine]
  English, Scientific journal, The loss of a cyclic change with two peaks of increased endometrial epidermal growth factor (EGF) concentration on days 2-4 and 13-14 during the estrous cycle has been linked to low fertility in repeat breeder (RB) cows. We have shown that an intravaginal infusion of osteopontin (OPN) restored the EGF profile in RB cows. The present study aimed to determine a structural element of OPN to restore the normal EGF profile and fertility. Holstein RB cows were diagnosed the EGF profile by a single examination of the endometrial EGF concentration on day 3 of the estrous cycle. Those with an altered EGF profile were intravaginally infused with OPN and its fragments on the day of insemination (day 0); the concentration of endometrial EGF was measured on day 3, and pregnancy was diagnosed on days 30-35. In Study 1, recombinant OPN (rOPN) (16 nmol), thrombin-cleaved N- and C-terminal fragments of rOPN (N-rOPN and C-rOPN, respectively), and a combination of these fragments (Th-rOPN) were infused (n = 13-20). The restoration rate of the normal EGF profile of the N-rOPN group (25.0 %) was a level in between the C-rOPN group (7.7 %) and both the rOPN (55.6 %) and Th-rOPN (64.3 %) groups. In Study 2, PBS (n = 47), rOPN (9.5 nmol, n = 83), and peptides of integrin binding motifs, GRGDSVAYGLK (peptide 1; 32, 320, and 1600 nmol), GRGDS (peptide 2; 320 and 1600 nmol), and SVAYGLK (peptide 3; 320 and 1600 nmol), were infused (n = 20-25). Restoration rates of the normal EGF profile of peptide 1 (320 and 1600 nmol) and peptide 3 (1600 nmol) groups (44.0-56.3 %) were comparable with those of the rOPN group (63.9 %) and higher than those of the PBS group (15.6 %). Restoration rates of the other groups were similar to those of the PBS group. Additional cows received infusions to determine the effect on fertility. Conception rates of the peptide 1 (320 and 1600 nmol; n = 50 each), peptide 3 (1600 nmol; n = 55), and rOPN (n = 111) groups (41.8-50.0 %) were comparable and higher than that of the PBS group (21.6 %, n = 75). In Study 3, PBS (n = 24), peptide 1 (320 nmol; n = 78), and GRGESVAYGLK peptide (peptide 4; 320 and 1600 nmol; n = 50 and 26, respectively) were infused. Restoration rates of the normal EGF profile of peptide 4 and PBS groups (16.0-19.2 %) were comparable and lower than those of the peptide 1 group (44.9 %). Thus, the SVAYGLK motif may be an OPN structural element to restore the normal EGF profile and fertility in RB cows, and the RGD motif may enhance its effect.
• Contraceptive effect of a gonadotropin-releasing hormone vaccine on captive male brown bears (Ursus arctos).
  Naoya Matsumoto; Jumpei Tomiyasu; Kyogo Hagino; Motozumi Matsui; Yojiro Yanagawa
  Reproduction in domestic animals = Zuchthygiene, 59, 9, e14707, Sep. 2024, [International Magazine]
  English, Scientific journal, Fertility control has traditionally been applied in zoos to control captive populations, and reversible contraception is important. However, contraceptive methods for male bears have not been reported. We aimed to establish a reversible contraceptive for male brown bears by investigating the effects of a gonadotropin-releasing hormone (GnRH) vaccine (Improvac®) that was developed for the immune castration of pigs. We vaccinated six bears with two sequential doses of 400 (n = 2) or 600 μg Improvac® (n = 4) with a 1-month interval during the pre-breeding season (February to April). We compared the reproductive parameters (testosterone levels and semen parameters) of the six vaccinated and four non-vaccinated (control) bears once during the breeding season (May or June). To investigate whether the reproductive performance could be restored in the following year of contraception, we also compared the reproductive parameters once during the breeding season in two bears between the year with GnRH vaccination and the following year without vaccination. Vaccination treatments suppressed reproductive parameters in 5 bears, although vaccination with 400 μg of Improvac® was not effective in one bear. Testosterone levels and the rate of progressive sperm motility were significantly lower, and total sperm count and testis size tended to be lower in vaccinated bears, compared with the controls. Blood biochemical findings and direct observations after Improvac® vaccination did not reveal side effects. Moreover, testosterone levels and spermatogenic scores of two bears were restored in the following year. We confirmed that the Improvac® vaccine elicited a reversible contraceptive effect in male brown bears.
• Physiological high temperatures alter amino acid metabolism of bovine early antral follicles
  Kohei Kawano; Kenichiro Sakaguchi; Nattapong Ninpetch; Yojiro Yanagawa; Seiji Katagiri
  Journal of Reproduction and Development, Mar. 2024, [Peer-reviewed]
  English, Scientific journal
• The value of evaluating luteal blood flow on the day of embryo transfer for recipient selection in Holstein lactating dairy cows
  Takashi Tanida; Itsuro Mukono; Mikiko Nakahashi; Daiki Miyano; Kurumi Miyazawa; Yojiro Yanagawa; Seiji Katagiri
  Japanese Journal of Veterinary Research, 71, 3, 72, 81, Feb. 2024, [Peer-reviewed]
• Effects of recombinant osteopontin expressed in Escherichia coli on the recovery of the endometrial epidermal growth factor profile and fertility in repeat breeder dairy cows
  Takashi Tanida; Takayoshi Tagami; Hiroko Sato; Hay Mar Kyaw; Takeshi Fujikawa; Masashi Nagano; Kenji Momozawa; Yojiro Yanagawa; Seiji Katagiri
  Theriogenology, Elsevier BV, Jan. 2024
  Scientific journal
• Effects of prostaglandin F2α treatment at follicular wave emergence on endometrial epidermal growth factor concentration on day of the next estrous cycle on fertility in dairy cows
  Vuong Tuan Phong; Takeshi Fujikawa; Kohei Kawano; Yojiro Yanagawa; Seiji Katagiri
  Theriogenology, 212, 189, 196, Elsevier, Sep. 2023, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• The Difference in Subpopulation Structures in Sex-Sorted and Non-Sorted Semen by Discriminant Analysis of Bull Sperm Motility Data Collected by a Computer-Assisted Sperm Analysis System
  Chihiro Kanno; Kentaro Q. Sakamoto; Sung-Sik Kang; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  Andrologia, 2023, 1, 7, Hindawi Limited, 24 May 2023
  Scientific journal, We examined the motility characteristics of sperm from sex-sorted bull semen as a model for low-quality (expected low conception rate) sperm compared to that of sperm from non-sorted semen (expected average conception rate) using cluster analysis followed by discriminant analysis. The results indicated that sex-sorted semen contained sperm with hyperactivation-like motility as the main subpopulation immediately after thawing, and this subpopulation decreased after 2 h of incubation. The main subpopulation in the non-sorted semen had progressive motility that was maintained during incubation. A conventional comparison of the mean values of kinematic parameters could not distinguish the samples. In conclusion, discriminant analysis using data from a cluster analysis of motile sperm may accurately describe differences in the structures of sperm motility subpopulations between low and normal fertility semen.
• Pre-maturational culture promotes the developmental competence of bovine oocytes derived from an 8-day in vitro growth culture system.
  Madalitso Chelenga; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  The Journal of reproduction and development, 69, 4, 214, 217, 18 May 2023, [Domestic magazines]
  English, Scientific journal, In this study, we evaluated the effects of pre-maturational culture (pre-IVM) on the developmental competence of bovine oocytes derived from an 8-day in vitro growth (IVG) culture system. IVG oocytes were subjected to 5 h pre-IVM before in vitro maturation, followed by in vitro fertilization (IVF). The proportion of oocytes that progressed to the germinal vesicle breakdown stage was similar between groups with and without pre-IVM. Although metaphase II oocytes and cleavage rates after IVF were similar regardless of pre-IVM culture, the blastocyst rate was significantly higher in the group with pre-IVM (22.5%) than without pre-IVM (11.0%, P < 0.05). In conclusion, pre-IVM culture improved the developmental competence of bovine oocytes derived from an 8-day IVG system.
• Age estimation based on blood DNA methylation levels in brown bears.
  Shiori Nakamura; Jumpei Yamazaki; Naoya Matsumoto; Miho Inoue-Murayama; Huiyuan Qi; Masami Yamanaka; Masanao Nakanishi; Yojiro Yanagawa; Mariko Sashika; Toshio Tsubota; Hideyuki Ito; Michito Shimozuru
  Molecular ecology resources, 23 Mar. 2023, [International Magazine]
  English, Scientific journal, Age is an essential trait for understanding the ecology and management of wildlife. A conventional method of estimating age in wild animals is counting annuli formed in the cementum of teeth. This method has been used in bears despite some disadvantages, such as high invasiveness and the requirement for experienced observers. In this study, we established a novel age estimation method based on DNA methylation levels using blood collected from 49 brown bears of known ages living in both captivity and the wild. We performed bisulfite pyrosequencing and obtained methylation levels at 39 cytosine-phosphate-guanine (CpG) sites adjacent to 12 genes. The methylation levels of CpGs adjacent to four genes showed a significant correlation with age. The best model was based on DNA methylation levels at just four CpG sites adjacent to a single gene, SLC12A5, and it had high accuracy with a mean absolute error of 1.3 years and median absolute error of 1.0 year after leave-one-out cross-validation. This model represents the first epigenetic method of age estimation in brown bears, which provides benefits over tooth-based methods, including high accuracy, less invasiveness, and a simple procedure. Our model has the potential for application to other bear species, which will greatly improve ecological research, conservation, and management.
• Relationship between Amino Acid Metabolism and Bovine In Vitro Follicle Activation and Growth
  Kenichiro Sakaguchi; Kohei Kawano; Yuki Otani; Yojiro Yanagawa; Seiji Katagiri; Evelyn E. Telfer
  Animals, 13, 7, 1141, 1141, MDPI AG, 23 Mar. 2023
  Scientific journal, The amino acid metabolism of bovine follicles during in vitro growth (IVG) was evaluated to identify potential indicators of health during culture. The bovine ovarian cortex was sliced, prepared as strips, and cultured for 6 days. Tissue samples were examined histologically before and after 6 days of culture, and the degree of follicle activation was classified as either high or low based on the number of growing secondary follicles present (high: 7~11; low: 0~1). In a separate experiment, secondary follicles (diameter range: 100~200 μm) were manually isolated and cultured, and their growth was monitored for 6 days. Cultured follicles were classified as growth or degenerate based on diameter change during culture (growth: +60.5~74.1 μm; degenerate: −28~15.2 μm). Free amino acids and their metabolites were measured in the spent culture medium from each group. In cultured ovarian cortical strips, the concentration of α-aminoadipic acid was significantly higher in the low activation group than in the high group (p < 0.05), while those of methionine, lysine, and arginine were higher in the high activation group. In cultured isolated secondary follicles, concentrations of methionine, tyrosine, histidine, and hydroxyproline were higher in the degenerate group (p ≤ 0.05). In conclusion, amino acid metabolism has the potential to serve as an indicator of primordial follicle activation and subsequent growth rate during bovine IVG.
• Analysis of sequential ruminal temperature sensor data from dairy cows to identify cow subgroups by clustering and predict calving through supervised machine learning.
  Eri Furukawa; Yojiro Yanagawa; Akira Matsuzaki; Heejin Kim; Hanako Bai; Masashi Takahashi; Seiji Katagiri; Shogo Higaki
  The Journal of reproduction and development, 69, 2, 103, 108, 17 Feb. 2023, [Domestic magazines]
  English, Scientific journal, The present study investigated the applicability of a calving prediction model based on supervised machine learning of ruminal temperature (RT) data in dairy cows. The existence of cow subgroups for prepartum RT changes was also examined, and the predictive performance of the model was compared among these subgroups. RT data were collected from 24 Holstein cows at 10 min intervals using an RT sensor system. The average hourly RT was calculated and data were expressed as residual RTs (rRT = actual RT - mean RT for the same time on the previous three days). The mean rRT decreased beginning at approximately 48 h before calving to a low of -0.5°C at 5 h before calving. However, two cow subgroups were identified: cows with a late and small rRT decrease (Cluster 1, n = 9) and those with an early and large rRT decrease (Cluster 2, n = 15). A calving prediction model was developed using five features extracted from the sensor data (indicative of prepartum rRT changes) through a support vector machine. Cross-validation showed that calving within 24 h was predicted with a sensitivity of 87.5% (21/24) and precision of 77.8% (21/27). A significant difference in sensitivity was observed between Clusters 1 and 2 (66.7 vs. 100%, respectively), while none was observed for precision. Therefore, the model based on RT data with supervised machine learning has the potential to efficiently predict calving, although improvements for specific cow subgroups are required.
• Relationship between frame rates and subpopulation structure of bovine sperm divided by their motility analyzed by a computer‐assisted sperm analysis system
  Chihiro Kanno; Kang Sun‐Sik; Kentaro Q. Sakamoto; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  Animal Science Journal, 93, 1, Wiley, Dec. 2022, [Peer-reviewed]
  English, Scientific journal
• アルパカの分娩予測法確立に向けた妊娠雌個体における糞中プロジェステロン濃度および体温推移の検討
  荒古江 美紗; 柳川 洋二郎; 前田 洋佑; 高橋 史昭; 佐藤 将伍; 桃沢 健二; 菅野 智裕
  日本獣医学会学術集会講演要旨集, 165回, [G1P, 11], (公社)日本獣医学会, Sep. 2022
  Japanese
• アルパカの分娩予測法確立に向けた妊娠雌個体における糞中プロジェステロン濃度および体温推移の検討
  荒古江 美紗; 柳川 洋二郎; 前田 洋佑; 高橋 史昭; 佐藤 将伍; 桃沢 健二; 菅野 智裕
  日本獣医学会学術集会講演要旨集, 165回, [G1P, 11], (公社)日本獣医学会, Sep. 2022
  Japanese
• Simultaneous free fatty acid elevations and accelerated desaturation in plasma and oocytes in early postpartum dairy cows under intensive feeding management
  Eri Furukawa; Zhen Chen; Tomoaki Kubo; Yue Wu; Koichiro Ueda; Madalitso Chelenga; Hitoshi Chiba; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano; Shu-Ping Hui
  Theriogenology, 193, 20, 29, Elsevier BV, Sep. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Effects of the presence of a large follicle and a corpus luteum in bovine ovaries on nuclear maturation of oocytes and steroidogenesis of granulosa cells cultured as oocyte-cumulus-granulosa complexes derived from early antral follicles
  Kenichiro Sakaguchi; Kohei Kawano; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  Japanese Journal of Veterinary Research, 70, 2, 45, 56, Aug. 2022, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Relationship between the timing of insemination based on estrus detected by the automatic activity monitoring system and conception rates using sex-sorted semen in Holstein dairy cattle.
  Eri Furukawa; Chihiro Kanno; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  The Journal of reproduction and development, 68, 4, 295, 298, 30 May 2022, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, We investigated the optimal timing of artificial insemination (AI) for achieving pregnancy according to the onset/end of estrus detected by an accelerometer system in Holstein cattle. The conception rates of conventional semen were used as a reference. The conception rate from AI of sex-sorted semen was higher at -4 to 4 h (57.1%) from the end of estrus than those at -12 to -4 h (37.7%) and 12-20 h (30.3%), whereas AI at 4-12 h showed an intermediate conception rate (47.4%). Conversely, conception rates were similar in AI performed between 0 and 32 h from the onset of estrus. Regarding conventional semen, the interval from the onset and end of estrus did not affect conception rates. The present results suggest that the time of the end of estrus is the better indicator of optimal AI timing for sex-sorted semen than the onset of estrus.
• Effect of heat exposure on the growth and developmental competence of bovine oocytes derived from early antral follicles.
  Kohei Kawano; Kenichiro Sakaguchi; Chelenga Madalitso; Nattapong Ninpetch; Shintaro Kobayashi; Eri Furukawa; Yojiro Yanagawa; Seiji Katagiri
  Scientific reports, 12, 1, 8857, 8857, 25 May 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, In dairy cows, low fertility caused by summer heat stress continues into the cooler autumn season. This can be caused by impaired oocyte quality in small growing follicles during summer. Here, we subjected oocyte-cumulus-granulosa complexes (OCGCs) derived from early antral follicles (0.5-1 mm) to in vitro growth (IVG) culture under two different temperature settings (the control and heat shock groups), and evaluated effects of heat exposure on growth and developmental competence of oocytes, factors affecting the developmental competence of oocytes (steroidogenesis of granulosa cells, oxidative stress in oocytes, and cell-to-cell communication between oocytes and somatic cells). Oocyte diameters after culture were smaller in the heat shock group. Although nuclear maturation and cleavage rates were similar between the groups, blastocyst rates were lower in the heat shock group (0.0%) than in the control group (27.7%), and reduced glutathione (GSH) levels in oocytes were lower in the heat shock group. Supplementation of cysteine, which stimulates GSH synthesis, increased GSH level and improved blastocyst rate of heat shocked oocytes (27.9%). These results suggest that heat exposure impairs the growth and developmental competence of oocytes in early antral follicles through GSH depletion, which can induce low fertility during summer and the following autumn.
• Effects of milk osteopontin on the endometrial epidermal growth factor profile and restoration of fertility in repeat breeder dairy cows
  Hay Mar Kyaw; Hiroko Sato; Takayoshi Tagami; Yojiro Yanagawa; Masashi Nagano; Seiji Katagiri
  Theriogenology, 184, 26, 33, Elsevier BV, May 2022, [Peer-reviewed], [International Magazine]
  Scientific journal
• Effects of heat stress on the endometrial epidermal growth factor profile and fertility in dairy cows.
  Kohei Kawano; Yojiro Yanagawa; Masashi Nagano; Seiji Katagiri
  The Journal of reproduction and development, 68, 2, 144, 151, 01 Apr. 2022, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, The endometrial epidermal growth factor (EGF) profile is an indicator of uterine function and fertility in cattle. The present study aimed to investigate the effects of heat stress on the endometrial EGF profile and fertility in lactating Holstein cows. The endometrial EGF profiles of 365 cows in the Hokkaido and Kyushu regions were examined between June and September (heat stress period, n = 211) and between October and January (control period, n = 154). EGF profiles were investigated using uterine endometrial tissues obtained by biopsy 3 days after estrus (Day 3). The proportion of cows with an altered EGF profile was higher between June and September than between October and January (41.2 vs. 16.2%, P < 0.05). The effects of rectal temperature on Days 0 and 3 on the endometrial EGF profile were also assessed in cows (n = 79) between June and September in the Kyushu region. A single embryo was transferred to cow on Day 7 to evaluate fertility (n = 67). Regardless of the rectal temperature on Day 3, the proportion of cows with an altered EGF profile was higher (64.1 vs. 30.0%, P < 0.05) and the pregnancy rate after embryo transfer (ET) was lower (26.7 vs. 51.4%, P < 0.05) in cows with a rectal temperature ≥ 39.5°C on Day 0 than in cows with a rectal temperature < 39.5°C on Day 0. The present results indicate that alterations in the endometrial EGF profile induced by an elevated body temperature on Day 0 contributed to reductions in fertility in lactating dairy cows during the heat stress period.
• Successful Laparoscopic Oviductal Artificial Insemination in the Endangered Tsushima Leopard Cat (Prionailurus bengalensis euptilurus).
  Akinori Azumano; Miya Ueda; Mika Nomura; Masashi Usui; Midori Ichinose; Yojiro Yanagawa; Satoshi Kusuda; Yuki Matsumoto; Koichi Murata
  Animals : an open access journal from MDPI, 12, 6, 19 Mar. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The Tsushima leopard cat (Prionailurus bengalensis euptilurus) is an endangered wild felid that lives solely on Tsushima Island, Nagasaki, Japan. Japan's Ministry of the Environment is working with the Japanese Association of Zoo and Aquariums for ex situ conservation of this species. However, considering genetic diversity, it is difficult to conduct captive breeding programs by natural breeding alone; hence, assisted reproductive technologies are required. This study aimed to breed Tsushima leopard cats, which otherwise cannot be paired, using laparoscopic oviductal artificial insemination (AI). Female Tsushima leopard cats (female 1, aged 7 years; female 2, aged 6 years) were treated with 200 IU equine chorionic gonadotropin, followed by administration of 1000 IU porcine luteinizing hormone (pLH) after 96 h to induce ovulation. Laparoscopic AI was performed 32 h post-pLH administration. Females 1 and 2 were inseminated in the oviduct with 2.4 × 10⁶ and 3.3 × 10⁶ motile spermatozoa, respectively, collected from two males. Pregnancy was confirmed by radiography 45 and 51 days post-AI in females 1 and 2, respectively; one fetus was found in female 2. Moreover, female 2 had spontaneous delivery of a female kitten 66 days post-AI. This is the first successful case of AI in a Tsushima leopard cat.
• Semen collection by urethral catheterization and electro-ejaculation with different voltages, and the effect of holding temperature and cooling rate before cryopreservation on semen quality in the Japanese macaque (Macaca fuscata).
  Noboru Takaesu; Chihiro Kanno; Kosuke Sugimoto; Masashi Nagano; Akihisa Kaneko; Yoriko Indo; Hiroo Imai; Hirohisa Hirai; Munehiro Okamoto; Mariko Sashika; Michito Shimozuru; Seiji Katagiri; Toshio Tsubota; Yojiro Yanagawa
  The Journal of veterinary medical science, 84, 3, 429, 438, 15 Mar. 2022, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  English, Scientific journal, In the Japanese macaque, semen has been collected by electro-ejaculation (EE), using the higher voltage stimuli compared to other species including genus Macaca. Semen coagulates immediately after ejaculation, which makes difficult to produce high-quality semen for artificial insemination. Recently, semen collection using urethral catheterization (UC) has been reported in carnivore and this technique may allow semen collection without coagulation in a less invasive manner. Further, the temporal preservation temperature and cooling rate of semen during cryopreservation affect post thawing sperm quality. In this study, to improve semen quality and quantity, as well as the animal welfare, semen collection was performed by EE with high (5-15 V) or low (3-6 V) voltage, UC and a combination of the two (EE-UC). It has been suggested that a high voltage is necessary for semen collection, but 10 V stimulation was effective enough and 15 V is for additional sperm collection. Also, liquid semen was collected by EE-UC and this could increase the total number of sperm. Further, to improve the post thawing sperm motility, semen was kept at four temperatures (4, 15, 25 and 37°C) for 60 min, and processed with two cooling procedures (slow cooling before second dilution and fast cooling after second dilution). Holding semen at 25°C and fast cooling after the second dilution maintained progressive motile sperm rate. The present results will contribute to the improvement of semen collection and animal welfare of Japanese macaques.
• Leptin receptor expression and its change in association with the normalization of EGF profile after seminal plasma treatment in repeat breeder dairy cows.
  Nattapong Ninpetch; Dagvajamts Badrakh; Kohei Kawano; Yojiro Yanagawa; Masashi Nagano; Seiji Katagiri
  The Journal of reproduction and development, 68, 3, 209, 215, 28 Feb. 2022, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Factors associated with high milk production levels have been linked to alterations in the endometrial epidermal growth factor (EGF) profile, a cause of reduced fertility in dairy cows. Therefore, we examined the leptin system that connects nutritional status and reproduction in dairy cattle related to reduced fertility in repeat breeder cows. Plasma leptin concentrations were measured in 18 heifers, 20 high-yielding control cows, and 26 repeat breeder cows, showing an altered EGF profile. Then, all repeat breeder cows were infused with seminal plasma (SP) into the vagina at the next estrus to normalize the EGF profile, while heifers and control cows were infused with vehicle alone. All animals were examined for EGF profiles. Eighteen repeat breeder cows, nine heifers, and nine control cows were also determined for leptin receptor (Ob-R) expression levels in the estrous cycle before and after the infusion. SP normalized the EGF profile in 53.8% of the repeat breeder cows. Leptin concentrations were similar in all groups, regardless of the treatment results for the EGF profile. In contrast, Ob-R levels in repeat breeder and control cows were similar and higher than those in heifers before SP treatment. Ob-R in repeat breeders showing a normal EGF profile after treatment decreased to an intermediate level between heifers and control cows and may provide a clue to take measures against repeat breeding in dairy cows.
• Ovulatory follicle size investigated by ultrasonography and single artificial insemination with ovulation induction in the Japanese macaque (Macaca fuscata)
  Takaesu N; Minami M; NaganoM; Kaneko A; Indo Y; Imai H; Hirai H; Sashika M; Shimozuru M; Okamoto M; Katagiri S; Tsubota T; Yanagawa Y
  Japanese Journal of Veterinary Research, 70, 1, 5, 17, 2022, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  Scientific journal
• Generation of viable calves derived from developmentally mature blastocysts produced by on-gel culture
  Shun SAITO; Hiroki AKIZAWA; Eri FURUKAWA; Yojiro YANAGAWA; Hanako BAI; Masashi TAKAHASHI; Manabu KAWAHARA
  Journal of Reproduction and Development, 68, 5, 330, 334, Japanese Society of Animal Reproduction, 2022, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Plasma profile of follicle-stimulating hormone and sex steroid hormones after a single epidural administration of follicle-stimulating hormone via caudal vertebrae in Holstein dry cows.
  Kenichiro Sakaguchi; Tomoko Suda; Nattapong Ninpetch; Kohei Kawano; Yojiro Yanagawa; Seiji Katagiri; Koji Yoshioka; Masashi Nagano
  Animal science journal = Nihon chikusan Gakkaiho, 93, 1, e13696, Jan. 2022, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The conventional follicle-stimulating hormone (FSH) treatment for bovine superstimulation involves multiple intramuscular injections, which is stressful for animals and onerous. We herein investigated whether a single epidural injection of porcine FSH (pFSH) can induce superovulation and peripheral concentrations of pFSH and steroid hormones after the treatment in Holstein dry cows. We intramuscularly administered pFSH twice daily to three cows for 3 days (control) or a single epidural pFSH administration (epidural). Numbers of follicles (≥10 mm in diameter) at estrus and corpora lutea at luteal phase were counted by ultrasonography. Blood was sampled from 0 to 104 h after the first pFSH administration and plasma pFSH, progesterone, androstenedione, testosterone, and estradiol-17β concentrations were measured. Numbers of follicles (control: 18.3 ± 7.5, epidural: 15.7 ± 4.0; mean ± SD) and corpora lutea (control: 7.3 ± 4.2, epidural: 8.0 ± 2.6) were similar between both treatments. Plasma pFSH concentrations were higher in epidural than in control (p < 0.01). Although no significant differences were observed in progesterone, androstenedione, or estradiol-17β concentrations between the groups, testosterone concentrations were slightly lower with the epidural treatment than with the control treatment (p = 0.08). In conclusion, superovulation was induced by a single epidural injection of pFSH, which achieved higher pFSH level than the multiple injections in Holstein dry cows.
• Postpartum cows showed high oocyte triacylglycerols concurrently with high plasma free fatty acids
  Eri Furukawa; Zhen Chen; Hiroki Ueshiba; Yue Wu; Hitoshi Chiba; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano; Shu-Ping Hui
  Theriogenology, 176, 174, 182, Elsevier BV, Dec. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Impaired oocyte quality is one of the main causes of low fertility in modern high-yielding dairy cows. One of the potential factors of the impaired oocyte quality is the effects of free fatty acids (FFA). In fact, high FFA supplementation to culture media exacerbated oocyte developmental competence in vitro. Meanwhile, artificially induced high blood FFA levels in heifers did not affect the lipid composition of oocytes in vivo; however, the oocyte lipid profile of postpartum cows has not yet been investigated. Therefore, the profile of lipids involved in energy metabolism, including FFA and triacylglycerols (TAG), and their relationship between plasma and oocytes were compared among cows at different lactation stages. Heifers were used as a control group that was not affected by lactation. Plasma and oocytes were collected from heifers (n = 4) and 14 Holstein cows categorized to the early lactation stage: 25-47 days in milk (DIM) (n = 6), peak lactation stage: 61-65 DIM (n = 4), and middle lactation stage: 160-202 DIM (n = 4). The FFA and TAG profiles of plasma and oocytes were examined by liquid chromatography mass spectrometry. Plasma FFA positively correlated with oocyte TAG (P < 0.05). Plasma FFA and oocyte TAG were significantly higher in cows in the early lactation stage than in heifers (P < 0.05), while the peak and middle lactation stage groups had intermediate levels. The proportion of oleic acid in plasma increased concurrently with elevations in total FFA, while the compositions of oocyte FFA and TAG fatty acyls were constant regardless of plasma FFA concentration or oocyte TAG content. The present results suggest that high postpartum plasma FFA concentrations affect the quantity of oocyte TAG. Taken together with the adverse effects of high FFA concentrations on oocyte developmental competence in vitro, oocyte quality in postpartum cows may be impaired due to high circulating FFA concentrations. These results provide a more detailed understanding of the effects of postpartum high circulating FFA concentrations on the low fertility of cows.
• Low oxygen environment and astaxanthin supplementation promote the developmental competence of bovine oocytes derived from early antral follicles during 8 days of in vitro growth in a gas-permeable culture device
  Madalitso Chelenga; Kenichiro Sakaguchi; Kohei Kawano; Eri Furukawa; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  Theriogenology, Elsevier BV, Oct. 2021, [Peer-reviewed], [International Magazine]
  Scientific journal
• Deciphering two rounds of cell lineage segregations during bovine preimplantation development.
  Hiroki Akizawa; Shun Saito; Nanami Kohri; Eri Furukawa; Yoshihiro Hayashi; Hanako Bai; Masashi Nagano; Yojiro Yanagawa; Hayato Tsukahara; Masashi Takahashi; Shinjiro Kagawa; Ryouka Kawahara-Miki; Hisato Kobayashi; Tomohiro Kono; Manabu Kawahara
  FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 35, 10, e21904, Oct. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Blastocyst formation gives rise to the inner cell mass (ICM) and trophectoderm (TE) and is followed by the differentiation of the epiblast (Epi) and primitive endoderm (PrE) within the ICM. Although these two-round cell lineage differentiations underpin proper embryogenesis in every mammal, their spatiotemporal dynamics are quite diverse among species. Here, molecular details of the blastocyst stage in cattle were dissected using an optimized in vitro culture method. Blastocyst embryos were placed on agarose gel filled with nutrient-rich media to expose embryos to both gaseous and liquid phases. Embryos derived from this "on-gel" culture were transferred to surrogate mothers on day (D) 10 after fertilization and successfully implanted. Immunofluorescent studies using on-gel-cultured embryos revealed that the proportion of TE cells expressing the pluripotent ICM marker, OCT4, which was beyond 80% on D8, was rapidly reduced after D9 and reached 0% on D9.5. This first lineage segregation process was temporally parallel with the second one, identified by the spatial separation of Epi cells expressing SOX2 and PrE cells expressing SOX17. RNA-seq comparison of TE cells from D8 in vitro fertilized embryos and D14 in vivo embryos revealed that besides drastic reduction of pluripotency-related genes, TE cells highly expressed Wnt, FGF, and VEGF signaling pathways-related genes to facilitate the functional maturation required for feto-maternal interaction. Quantitative PCR analysis of TE cells derived from on-gel culture further confirmed time-dependent increments in the expression of key TE markers. Altogether, the present study provides platforms to understand species-specific strategies for mammalian preimplantation development.
• 第二胃内留置型自動体温測定器で測定したホルスタイン種経産牛の分娩前1週間の体温変化と分娩時間帯の関係
  古川 瑛理; 高橋 昌志; 松崎 明; 唄 花子; 永野 昌志; 片桐 成二; 柳川 洋二郎
  日本畜産学会大会講演要旨集, 129回, 117, 117, (公社)日本畜産学会, Sep. 2021
  Japanese
• Programmed death-ligand 1 expression in swine chronic infections and enhancement of interleukin-2 production via programmed death-1/programmed death-ligand 1 blockade.
  Otgontuya Ganbaatar; Satoru Konnai; Tomohiro Okagawa; Yutaro Nojima; Naoya Maekawa; Yoshiki Ichikawa; Atsushi Kobayashi; Tomoyuki Shibahara; Yojiro Yanagawa; Hidetoshi Higuchi; Yukinari Kato; Yasuhiko Suzuki; Shiro Murata; Kazuhiko Ohashi
  Immunity, inflammation and disease, 9, 4, 1573, 1583, 20 Aug. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, INTRODUCTION: Chronic infections lead to the functional exhaustion of T cells. Exhausted T cells are phenotypically differentiated by the surface expression of the immunoinhibitory receptor, such as programmed death-1 (PD-1). The inhibitory signal is produced by the interaction between PD-1 and its PD-ligand 1 (PD-L1) and impairs the effector functions of T cells. However, the expression dynamics of PD-L1 and the immunological functions of the PD-1/PD-L1 pathway in chronic diseases of pigs are still poorly understood. In this study, we first analyzed the expression of PD-L1 in various chronic infections in pigs, and then evaluated the immune activation by the blocking assay targeting the swine PD-1/PD-L1 pathway. METHODS: In the initial experiments, anti-bovine PD-L1 monoclonal antibodies (mAbs) were tested for cross-reactivity with swine PD-L1. Subsequently, immunohistochemical analysis was conducted using the anti-PD-L1 mAb. Finally, we assessed the immune activation of swine peripheral blood mononuclear cells (PBMCs) by the blockade with anti-PD-L1 mAb. RESULTS: Several anti-PD-L1 mAbs tested recognized swine PD-L1-expressing cells. The binding of swine PD-L1 protein to swine PD-1 was inhibited by some of these cross-reactive mAbs. In addition, immunohistochemical analysis revealed that PD-L1 was expressed at the site of infection in chronic infections of pigs. The PD-L1 blockade increased the production of interleukin-2 from swine PBMCs. CONCLUSIONS: These findings suggest that the PD-1/PD-L1 pathway could be also involved in immunosuppression in chronic infections in pigs. This study provides a new perspective on therapeutic strategies for chronic diseases in pigs by targeting immunosuppressive pathways.
• Macrophage ubiquitin-specific protease 2 contributes to motility, hyperactivation, capacitation, and in vitro fertilization activity of mouse sperm.
  Mayuko Hashimoto; Shunsuke Kimura; Chihiro Kanno; Yojiro Yanagawa; Takafumi Watanabe; Jun Okabe; Eiki Takahashi; Masashi Nagano; Hiroshi Kitamura
  Cellular and molecular life sciences : CMLS, 78, 6, 2929, 2948, Mar. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Macrophages are innate immune cells that contribute to classical immune functions and tissue homeostasis. Ubiquitin-specific protease 2 (USP2) controls cytokine production in macrophages, but its organ-specific roles are still unknown. In this study, we generated myeloid-selective Usp2 knockout (msUsp2KO) mice and specifically explored the roles of testicular macrophage-derived USP2 in reproduction. The msUsp2KO mice exhibited normal macrophage characteristics in various tissues. In the testis, macrophage Usp2 deficiency negligibly affected testicular macrophage subpopulations, spermatogenesis, and testicular organogenesis. However, frozen-thawed sperm derived from msUsp2KO mice exhibited reduced motility, capacitation, and hyperactivation. In addition, macrophage Usp2 ablation led to a decrease in the sperm population exhibiting high intracellular pH, calcium influx, and mitochondrial membrane potential. Interrupted pronuclei formation in eggs was observed when using frozen-thawed sperm from msUsp2KO mice for in vitro fertilization. Administration of granulocyte macrophage-colony stimulating factor (GM-CSF), whose expression was decreased in testicular macrophages derived from msUsp2KO mice, restored mitochondrial membrane potential and total sperm motility. Our observations demonstrate a distinct role of the deubiquitinating enzyme in organ-specific macrophages that directly affect sperm function.
• Seroprevalence of fasciolosis in Hokkaido sika deer (Cervus nippon yesoensis) from Hokkaido Prefecture, Japan revealed by ELISA using recombinant cathepsin L1.
  Hironobu Sato; Hiroki Hiraya; Takutoshi Sugiyama; Shinya Fukumoto; Ryota Matsuyama; Yojiro Yanagawa; Ryo Nakao; Takao Irie; Kensuke Taira; Akiko Yamazaki; Katsuro Hagiwara; Ayako Yoshida; Yoichi Kamata; Madoka Ichikawa-Seki
  Parasitology international, 80, 102222, 102222, Feb. 2021, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Fasciolosis, a zoonotic disease caused by liver flukes of the genus Fasciola, has been reported in Hokkaido (Yezo) sika deer (Cervus nippon yesoensis) in Hokkaido Prefecture, Japan; however, the actual seroprevalence in the animal has not been adequately evaluated. The objective of the present study was to analyze the seroprevalence of the disease among Hokkaido sika deer. Recombinant cathepsin L1 (rCatL1) was used as an antigen for an indirect enzyme-linked immunosorbent assay (ELISA) to detect antibodies against Fasciola flukes. The sensitivity and specificity of the ELISA were 84.6% and 100%, respectively. The average seroprevalence in 1109 Hokkaido sika deer from 20 locations in Hokkaido Prefecture was 43.9%. Mature deer showed higher seroprevalence than younger individuals; however, even younger animals may act as a reservoir for the disease. Monitoring infection levels in the Hokkaido sika deer population is important not only for the livestock industry, but also for preventing human fasciolosis.
• Monitoring follicular dynamics to determine estrus type and timing of ovulation induction in captive brown bears (Ursus arctos).
  Yoshiko Torii; Naoya Matsumoto; Hideyuki Sakamoto; Masashi Nagano; Seiji Katagiri; Yojiro Yanagawa
  The Journal of reproduction and development, 66, 6, 563, 570, 22 Dec. 2020, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  English, Scientific journal, It is important to understand ovarian physiology when developing an artificial insemination (AI) protocol. Brown bears (Ursus arctos) have a breeding season from May to July, although the type of estrus (polyestrus or monoestrus) is still contested. The present study aimed to define the ovarian dynamics, including follicular waves and ovulatory follicle size, and estrus type in brown bears. Six brown bears were used for ovarian ultrasonography; four were observed between April and October (before the start and after the end of the breeding season) and two in June (breeding season). In addition, we attempted to induce ovulation by administering a gonadotropin releasing hormone (GnRH) agonist. We observed follicular development in April in four bears, but follicles did not develop to greater than 6.0 mm in diameter until May. Thereafter, a group of follicles developed to more than 6.0 mm and grew as dominant follicles, except in one bear. After ovulation and subsequent corpus luteum (CL) formation, the follicular waves disappeared. Furthermore, in three bears treated with GnRH, follicles between 8.2 to 11.2 mm in diameter at the time of treatment ovulated and formed CLs. In two bears, follicles between 5.8 to 8.8 mm ovulated spontaneously within the observation interval. Our results suggest that brown bears may be monoestrous animals. Therefore, AI can only be performed once during the breeding season. Our results also suggest that dominant follicles larger than 8.0 mm are a suitable size for inducing ovulation.
• Hair growth in brown bears and its application to ecological studies on wild bears
  Mina Jimbo; Naoya Matsumoto; Hideyuki Sakamoto; Yojiro Yanagawa; Yoshiko Torii; Masami Yamanaka; Tsuyoshi Ishinazaka; Yuri Shirane; Mariko Sashika; Toshio Tsubota; Michito Shimozuru
  MAMMAL STUDY, 45, 4, 337, 345, Oct. 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Effect of increased oxygen availability and astaxanthin supplementation on the growth, maturation and developmental competence of bovine oocytes derived from early antral follicles
  Madalitso Chelenga; Kenichiro Sakaguchi; Mohammed A. Abdel-Ghani; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  Theriogenology, 157, 341, 349, Elsevier BV, Aug. 2020, [Peer-reviewed], [International Magazine]
  Scientific journal
• Identification of bovine seminal plasma proteins with an activity to normalize endometrial epidermal growth factor concentrations in repeat breeder cows
  Dagvajamts Badrakh; Atsushi Shirasawa; Yojiro Yanagawa; Masashi Nagano; Seiji Katagiri
  JAPANESE JOURNAL OF VETERINARY RESEARCH, 68, 2, 91, 103, May 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Effect of seminal plasma infusion into the vagina on the normalization of endometrial epidermal growth factor concentrations and fertility in repeat breeder dairy cows.
  Dagvajamts Badrakh; Yojiro Yanagawa; Masashi Nagano; Seiji Katagiri
  The Journal of reproduction and development, 66, 2, 149, 154, 28 Jan. 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Epidermal growth factor (EGF) concentrations in the uterus show two peaks on days 2-4 and 13-14 during the estrous cycle in fertile cows. Loss of the two peaks has been linked to reduced fertility in repeat breeder cows. This study aimed to examine the effect of seminal plasma (SP) on normalizing endometrial EGF concentrations and restoring fertility in repeat breeder cows with low EGF concentrations on day 3. In study 1, we examined the effect of the deposition sites (the vagina and uterus) of SP on the endometrial EGF concentrations in repeat breeder cows. SP infusion into the vagina, but not uterus, on the first day of the estrus cycle (day 0) normalized the endometrial EGF concentrations (≥ 4.7 ng/g tissue weight) on day 3. In study 2, the effect of SP volume (0.5 and 10 ml of SP and 0.5 ml of SP diluted to 10 ml) on EGF concentration was examined. All groups with SP infusion had increased EGF concentrations on day 3, and cows with 10 ml of SP and 0.5 ml of SP diluted to 10 ml showed the highest levels of EGF concentrations. In study 3, we examined the effect of SP infusion on fertility. SP infusion normalized two peaks of endometrial EGF concentrations in about 60% of repeat breeder cows and produced more pregnancies than the controls (44.4 vs. 19.4%). Therefore, we concluded that SP may contain an activity to normalize the EGF profile and restore fertility in repeat breeder cows with altered EGF profiles.
• 動物園における人工繁殖学総論
  柳川 洋二郎
  日本飼育技術学会誌, -, 5, 18, 2020
  Scientific journal
• Effect of summer heat stress on gene expression in bovine uterine endometrial tissues.
  Hanako Bai; Haruka Ukita; Manabu Kawahara; Tomohiro Mitani; Eri Furukawa; Yojiro Yanagawa; Naoto Yabuuchi; Heejin Kim; Masashi Takahashi
  Animal science journal = Nihon chikusan Gakkaiho, 91, 1, e13474, Jan. 2020, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Heat stress negatively affects reproductive functions in cows. Increased temperature disturbs fetal development in utero. However, the effect of heat stress on uterine endometrial tissues has not been fully examined. Using qPCR analysis, we measured the mRNA expression of various molecular markers in uterine endometrial tissue of dairy cows from Hokkaido, Japan, in winter and summer. Markers examined were heat shock proteins (HSPs), antioxidant enzymes (catalase, copper/zinc superoxide dismutase, manganese superoxide dismutase, and glutathione peroxidase 4), inflammatory cytokines, and interferon stimulated genes. Our results showed heat stress, body and milk temperatures were higher during summer than during winter. Expression levels of HSP27, HSP60, and HSP90 mRNA, and of catalase and copper/zinc superoxide dismutase mRNA were lower in summer than in winter. Tumor necrosis factor alpha expression was higher in summer than in winter. In conclusion, summer heat stress may reduce the expression of HSPs, affecting the levels of inflammatory cytokines in bovine uterine endometrial tissue.
• Relationship between the timing of the first postpartum ovulation and antral follicle counts in Holstein cows
  Furukawa E; Masaki T; Sakaguchi K; Bo M; Yanagawa Y; Ueda K; Nagano M
  Journal of Ovarian Research, 13, 1, 7, 7, Jan. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: The timing of the first postpartum ovulation is an important factor affecting the timing of estrous resumption in dairy cows. The first postpartum ovulation is delayed in cows producing large amounts of milk with an intensive negative energy balance. The antral follicle count (AFC) and serum anti-Müllerian hormone concentrations are known to be indicators of the ovarian reserve, which is the number and quality of follicles left in a pair of ovaries and known as an indicator of female fertility. Cows with higher AFC have been proven to show higher pregnancy rate and shorter calving to conception intervals; however, the relationship between the timing of the first postpartum ovulation and ovarian reserve remains unclear. Therefore, this study examined the relationships between postpartum follicular dynamics, the ovarian cycle, nutritional status, and ovarian reserve. METHODS: Transrectal ultrasonography was conducted from calving to 70-120 days in milk (DIM) in 26 cows to monitor AFC, follicular dynamics and the ovarian cycle. Body weight (BW) and milk yield were used as indicators of nutritional status. RESULTS: The first postpartum ovulation was significantly later in cows with low AFC (< 25) than in those with high AFC (≥25), while changes in BW from calving to the nadir and milk production were similar in both groups. The present results also suggested that cows with low AFC and a delayed first postpartum ovulation had a shorter first ovarian cycle after the first postpartum ovulation. The mean DIM of the first postpartum artificial insemination (AI) and days open (days from calving to AI with which pregnancy was achieved) were similar in high and low AFC groups. CONCLUSIONS: The first postpartum ovulation was significantly earlier in cows with high AFC than in those with low AFC. The assumed reason for this result was higher sensitivity to luteinizing hormone and larger androstenedione and estradiol production in follicles in high AFC cows. Therefore, cows with high AFC may be more fertile than those with low AFC while their milk production increase and BW decrease; it means they are in negative energy balance. (340/350 words).
• Theca cells can support bovine oocyte growth in vitro without the addition of steroid hormones
  Yang Y; Kanno C; Sakaguchi K; Katagiri S; Yanagawa Y; Nagano M
  Theriogenology, 142, 41, 47, Jan. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Theca cells (TCs) are essential to folliculogenesis by contributing to steroidogenesis. However, the in vitro growth (IVG) of oocytes co-cultured with TCs has not yet been examined. In the present study, we investigated the feasibility of the IVG of bovine oocyte-cumulus-granulosa cell complexes (OCGCs) co-cultured with TCs and the developmental competence of co-cultured oocytes. OCGCs and TCs were co-cultured without steroid hormone addition for 12 days. Steroidogenesis, the viability of OCGCs, and TC numbers during co-culture were assessed every 4 days. After IVG, oocytes were matured and the nuclear status was evaluated. Some oocytes were inseminated and cultured to examine blastocyst development. During the co-culture, androstenedione production by TCs was only observed during the first 4 days (1.1 ng/well) while estradiol-17β was continuously produced, peaking during the second 4 days (0.5 ng/well). The number of TCs decreased to ∼60% of the seeding number (4.0 × 104 cells/well) during the first 4 days, and was maintained thereafter. The majority of co-cultured OCGCs (82.7%) survived after 12-day IVG. Only a few OCGCs (6.2%) survived in the OCGC culture without TCs (p < 0.01); however, the addition of androstenedione to the culture medium markedly improved survivability to 80.1%, which was similar to that in the co-culture with TCs. In the subsequent development of oocytes derived from the co-culture, 58.3% reached metaphase II stage, 58.7% cleaved, and 17.3% developed to blastocysts, which were similar values to those of oocytes cultured with the addition of androstenedione. In conclusion, TC-produced androgen contributes to OCGC growth and the acquisition of subsequent embryonic developmental competence.
• Trophectoderm regeneration to support full-term development in the inner cell mass isolated from bovine blastocyst.
  Kohri N; Akizawa H; Iisaka S; Bai H; Yanagawa Y; Takahashi M; Komatsu M; Kawai M; Nagano M; Kawahara M
  The Journal of biological chemistry, 294, 50, 19209, 19223, Nov. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Which comes first: tissue structure or cell differentiation? Although different cell types establish distinct structures delineating the inside and outside of an embryo, they progressively become specified by the blastocyst stage, when two types of cell lineages are formed: the inner cell mass (ICM) and the trophectoderm (TE). This inside-outside aspect can be experimentally converted by the isolation of the ICM from a blastocyst, leading to a posteriori externalization of the blastomeres composing the outermost layer of the ICM. Here, we investigated the totipotency of isolated mouse and bovine ICMs to determine whether they are competent for TE regeneration. Surprisingly, a calf was generated from the bovine isolated ICM with re-formed blastocoel (re-iICM), but no mouse re-iICMs developed to term. To further explore the cause of difference in developmental competency between the mouse and bovine re-iICMs, we investigated the SOX17 protein expression that is a representative molecular marker of primitive endoderm. The localization pattern of SOX17 was totally different between mouse and bovine embryos. Particularly, the ectopic SOX17 localization in the TE might be associated with lethality of mouse re-iICMs. Meanwhile, transcriptome sequencing revealed that some of the bovine re-iICMs showed transcriptional patterns of TE-specific genes similar to those of whole blastocysts. Our findings suggest that TE regeneration competency is maintained longer in bovine ICMs than in mouse ICMs and provide evidence that the ICM/TE cell fate decision is influenced by structural determinants, including positional information of each blastomere in mammalian embryos.
• Relationships between the antral follicle count, steroidogenesis, and secretion of follicle-stimulating hormone and anti-Müllerian hormone during follicular growth in cattle.
  Sakaguchi K; Yanagawa Y; Yoshioka K; Suda T; Katagiri S; Nagano M
  Reproductive biology and endocrinology : RB&E, 17, 1, 88, 88, Nov. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, BACKGROUND: The antral follicle count (AFC) in mammalian ovaries positively correlates with female fertility. To clarify the causes of differences in fertility between low and high AFC cows, we investigated follicular growth dynamics and hormone concentrations in plasma, follicular fluid, and in vitro growth (IVG) media at different stages of follicular growth. METHODS: Seven cows were divided into high AFC (n = 4, > 30 follicles) and low AFC (n = 3, < 30 follicles) groups based on the peak AFC detected by ultrasonography. These cows were subjected to estrous synchronization, daily ovarian ultrasonography, and blood collection. Their follicular fluid was collected from dominant follicles at different stages (selection, luteal, and ovulatory phases). In another experiment, we cultured oocyte-cumulus-granulosa cell complexes collected from early antral follicles (< 1 mm) for 12 days. Estradiol-17β (E2), testosterone (T), progesterone (P4), and anti-Müllerian hormone (AMH) concentrations in follicular fluids and plasma were measured. Plasma follicle-stimulating hormone (FSH) concentrations were examined. E2, P4, and AMH concentrations were also measured in IVG media. RESULTS: The numbers of small (< 4 mm) and intermediate (4-8 mm) follicles were larger in the high AFC group than in the low AFC group (P < 0.05). The number of intermediate follicles was stable in the low AFC group, indicating consistent development. However, the number of these follicles fluctuated in the high AFC group. Plasma FSH concentrations were higher, whereas E2 and T concentrations were lower in the low AFC group (P < 0.05). E2 concentrations and the E2/P4 ratio in ovulatory follicles and IVG media on day 8 were higher in the high AFC group (P < 0.05). AMH concentrations in plasma and IVG media (P < 0.01) were higher in the high AFC group. CONCLUSIONS: The weaker response to FSH of granulosa cells caused low E2 production in the low AFC group, resulting in high FSH concentrations and the consistent development of intermediate follicles. Conversely, higher E2 concentrations suppressed FSH secretion in the high AFC group. Granulosa cells in the high AFC group had the ability to produce more AMH than those in the low AFC group throughout IVG culture.
• Monitoring follicular dynamics using ultrasonography in captive brown bears (Ursus arctos) during the breeding season
  Torii Y; Matsumoto N; Sakamoto H; Nagano M; Katagiri S; Yanagawa Y
  Theriogenology, 140, 164, 170, Aug. 2019, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Artificial insemination (AI) may be a useful tool in the reproductive management of endangered animals, including bears. To establish an AI program for bears, we investigated follicular dynamics using weekly transrectal ultrasonography in six captive brown bears. Along with ultrasonography, we monitored plasma progesterone (P4) and estradiol-17β (E2) concentrations. Furthermore, two bears were administered a gonadotropin releasing hormone (GnRH) agonist to induce ovulation on the first day on which the largest follicle reached more than 10.0 mm in diameter. Brown bears showed two patterns of follicular development in the early and late periods of the breeding season. In the early period (May to mid-June), multiple follicular waves were observed; namely, many follicles developed, and the largest follicles grew to less than 6.0 mm in diameter then regressed. In the late period (mid-June to July), one or two follicles grew to greater than 6.0 mm in diameter and developed as dominant follicles. Moreover, the growth rate of the largest follicle in the late period was faster than that in the early period of the breeding season. One bear with a follicle of 13.1 mm ovulated spontaneously, and one bear ovulated when the follicle was 10.2 mm in diameter after GnRH agonist treatment. Plasma E2 concentrations increased and showed peaks five to seven days before the largest follicles reached their maximum size. Plasma P4 concentrations increased on the day the corpus luteum could be detected using ultrasonography. This is the first study that showed there are two patterns of follicular development in brown bears. Furthermore, the largest follicle reaching greater than 10.0 mm in diameter could be an indicator of the appearance of ovulatory follicles.
• Effects of follicle-stimulating hormone followed by gonadotropin-releasing hormone on embryo production by ovum pick-up and in vitro fertilization in the river buffalo (Bubalus bubalis).
  Sakaguchi K; Maylem ERS; Tilwani RC; Yanagawa Y; Katagiri S; Atabay EC; Atabay EP; Nagano M
  Animal science journal = Nihon chikusan Gakkaiho, 90, 5, 690, 695, Mar. 2019, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, In this study, we examined the effects of superstimulation using follicle-stimulating hormone (FSH) followed by gonadotropin-releasing hormone (GnRH) on buffalo embryo production by ultrasound-guided ovum pick-up (OPU) and in vitro fertilization (IVF). Nine Murrah buffaloes were subjected to OPU-IVF without superstimulation (control). The morphologies of the oocytes collected were evaluated, and oocytes were then submitted to in vitro maturation (IVM). Two days after OPU, same nine buffaloes were treated with twice-daily injections of FSH for 3 days for superstimulation followed by a GnRH injection. Oocytes were collected by OPU 23-24 hr after the GnRH injection and submitted to IVM (the superstimulated group). The total number of follicles, number of follicles with a diameter > 8 mm, and number of oocytes surrounded by multi-layered cumulus cells were higher in the superstimulated group than in the control group (p ≤ 0.05). After IVF, the percentages of cleavage and development to blastocysts were higher in the superstimulated group than in the control group (p < 0.05). In conclusion, superstimulation improved the quality of oocytes and the embryo productivity of OPU-IVF in river buffaloes.
• Astaxanthin improves the developmental competence of in vitro-grown oocytes and modifies the steroidogenesis of granulosa cells derived from bovine early antral follicles.
  M A Abdel-Ghani; Y Yanagawa; A Z Balboula; K Sakaguchi; C Kanno; S Katagiri; M Takahashi; M Nagano
  Reproduction, fertility, and development, 31, 2, 272, 281, Jan. 2019, [Peer-reviewed], [International Magazine]
  English, Scientific journal, In this study we investigated the effect of astaxanthin (Ax), which exhibits strong antioxidant activity, during invitro growth (IVG) on the developmental competence of oocytes and steroidogenesis of granulosa cells derived from early antral follicles. Bovine oocyte-cumulus-granulosa complexes collected from early antral follicles were cultured for 12 days in the presence or absence (control) of 500µM Ax. The viability of oocytes and antrum formation in the granulosa cell layer during IVG culture were greater in the presence than absence of Ax (P<0.05). Regardless of Ax treatment, 17β-oestradiol production increased during IVG culture; however, progesterone production was significantly lower in the presence than absence of Ax (P<0.05). Reactive oxygen species levels were lower in Ax-treated oocytes than in controls after IVG (P<0.05). Although nuclear maturation and cleavage rates did not differ between the Ax-treated and control groups, Ax treatment led to weaker cathepsin B activity in oocytes and better blastocyst rates than in controls (P<0.05). Accordingly, Ax treatment during IVG increased the total number of cells in blastocysts (P<0.05). These results indicate that Ax supplementation of IVG medium improves the quality of bovine oocytes due to its antioxidative effects on growing oocytes and its suppression of the luteinisation of granulosa cells.
• Significance of CCN2 expression in bovine preimplantation development.
  Akizawa H; Yanagawa Y; Nagano M; Bai H; Takahashi M; Kawahara M
  Animal science journal = Nihon chikusan Gakkaiho, 90, 1, 49, 54, Jan. 2019, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, In mammalian preimplantation development, the first cell lineage segregation occurs during the blastocyst stage, when the inner cell mass and trophectoderm (TE) differentiate. Species-specific analyses are essential to elucidate the molecular mechanisms that underlie this process, since they differ between various species. We previously showed that the reciprocal regulation of CCN2 and TEAD4 is required for proper TE differentiation in bovine blastocysts; however, the function of CCN2 during early embryogenesis has remained otherwise elusive. The present study assessed the spatiotemporal expression dynamics of CCN2 in bovine embryos, and evaluated how changes to CCN2 expression (using a CCN2 knockdown (KD) blastocyst model) regulate the expression of pluripotency-related genes such as OCT4 and NANOG. The conducted quantitative PCR analysis revealed that CCN2 mRNA was expressed in bovine oocytes (at the metaphase stage of their second meiosis) and embryos. Similarly, immunostaining detected both cytoplasmic and nuclear CCN2 at all analyzed oocyte and embryonic stages. Finally, both OCT4 and NANOG expression levels were shown to be significantly reduced in CCN2 KD blastocysts. Together, these results demonstrate that bovine CCN2 exhibits unique expression patterns during preimplantation development, and is required for the proper expression of key regulatory genes in bovine blastocysts.
• Effect of astaxanthin addition to an individual culture system for in vitro maturation of bovine oocytes on accumulation of reactive oxygen species and mitochondrial activity
  Erdenetogtokh P; Kanno C; Sakaguchi K; Yanagawa Y; Katagiri S; Nagano M
  Japanese Journal of Veterinary Research, 66, 4, 325, 329, Nov. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Relationship between the antral follicle count in bovine ovaries from a local abattoir and steroidogenesis of granulosa cells cultured as oocyte-cumulus-granulosa complexes.
  Sakaguchi K; Tanida T; Abdel-Ghani MA; Kanno C; Yanagawa Y; Katagiri S; Nagano M
  The Journal of reproduction and development, 64, 6, 503, 510, Aug. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, The antral follicle count (AFC) is used as an indicator of cow fertility. We herein investigated the relationship between AFC and the steroidogenesis of granulosa cells and confirmed the developmental competence of oocytes derived from early antral follicles (0.5-1.0 mm) using in vitro growth culture. Slaughterhouse-derived ovaries were divided into high (≥ 25) and low (< 25) AFC groups based on AFC (≥ 2.0 mm). Oocyte-cumulus-granulosa complexes (OCGCs) collected from early antral follicles were cultured for 12 days. The total number, viability, and diameter of granulosa cells and estradiol-17β and progesterone production during the culture were evaluated. Surviving oocytes on day 12 were subjected to in vitro maturation, and their volume and nuclear status were evaluated. Some oocytes were subjected to the evaluation of developmental competence to blastocysts. Although the total number and viability of granulosa cells did not differ between the groups, granulosa cell diameters were smaller in the high AFC group than in the low AFC group. The estradiol-17β and progesterone ratio on day 8 was higher in the high AFC group than in the low AFC group. Oocyte volumes and nuclear maturation rates were greater in the high AFC group than in the low AFC group. The development rate to blastocysts was 9.1% in the high AFC group, while no oocytes developed to blastocysts in the low AFC group. Therefore, estradiol-17β production by granulosa cells appears to be greater in high AFC cattle than in low AFC cattle, thereby promoting the acquisition of oocyte competence.
• Effects of pre-maturational culture duration on developmental competence of bovine small-sized oocytes
  Abdel-Ghani Mohammed. A; Sakaguchi Kenichiro; Kanno Chihiro; Yanagawa Yojiro; Katagiri Seiji; Nagano Masashi
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 64, 4, 365, 369, Aug. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Testicular regulation of seasonal change in apocrine glands in the back skin of the brown bear (Ursus arctos).
  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, Jun. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Brown bears communicate with other individuals using marking behavior. Bipedal back rubbing has been identified as a common marking posture. Oily substances are secreted via enlarged sebaceous glands in the back skin of male bears during the breeding season. However, whether apocrine gland secretions are associated with seasonal changes remains unknown. The present study aimed to identify histological and histochemical changes in the secretory status and the glycocomposition of the apocrine glands in the back skin of male bears in response to changes in seasons and/or reproductive status. The apocrine glands of intact males during the breeding season were significantly larger and more active than those of castrated males during the breeding season and those of intact males during the non-breeding season. Lectin histochemical analyses revealed a more intense reaction to Vicia villosa agglutinin (VVA) in the cytoplasm, mainly Golgi zones of apocrine cells during the breeding season among castrated, compared with intact males. Positive staining for VVA was quite intense and weak in intact males during the non-breeding and breeding seasons, respectively. Ultrastructural analysis revealed VVA positivity in the Golgi zone, especially around secretory granules in apocrine cells. Changes in lectin binding might reflect a change in the secretory system in the apocrine cells. The present histological and histochemical findings of changes in the secretory status and glycocomposition of the apocrine glands according to the season and reproductive status suggest that these glands are important for chemical communication.
• Effect of a single epidural administration of follicle-stimulating hormone via caudal vertebrae on superstimulation for in vivo and in vitro embryo production in Japanese black cows.
  Sakaguchi K; Ideta A; Yanagawa Y; Nagano M; Katagiri S; Konishi M
  The Journal of reproduction and development, 64, 5, 451, 455, Jun. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal, Here, we describe a simplified procedure for embryo production in the Japanese black cow that uses a single caudal epidural injection of follicle-stimulating hormone (FSH). First, we compared the efficiency of superovulation for in vivo embryo production between conventional multiple FSH treatment (control, n = 10) and single epidural administration (epidural, n = 5). The number of transferable blastocysts was similar between control and epidural groups (4.7 ± 3.5 and 9.0 ± 6.0, respectively). Next, we compared in vitro embryo production by ovum pick-up and in vitro fertilization (OPU-IVF) between control (n = 12) and epidural groups (n = 12). The rate of development to transferable blastocysts was higher in the epidural group than in the control (23.3 vs. 10.5%, P < 0.001). In conclusion, a single epidural administration of FSH can induce follicular development comparable to that of the conventional superovulation protocol and may improve the productivity of OPU-IVF.
• Evaluation of the chemiluminescent enzyme immunoassay system for the measurement of testosterone in the serum and whole blood of stallions
  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, Feb. 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Testosterone-related and seasonal changes in sebaceous glands in the back skin of adult male brown bears (Ursus arctos)
  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, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Relationship between bovine endometrial thickness and plasma progesterone and estradiol concentrations in natural and induced estrus
  Tomochika Sugiura; Shun Akiyoshi; Fumihiro Inoue; Yojiro Yanagawa; Masaharu Moriyoshi; Motoshi Tajima; Seiji Katagiri
  Journal of Reproduction and Development, 64, 2, 135, 143, 2018, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Extension of the culture period for the in vitro growth of bovine oocytes in the presence of bone morphogenetic protein-4 increases oocyte diameter, but impairs subsequent developmental competence
  Yinghua Yang; Chihiro Kanno; Kenichiro Sakaguchi; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  ANIMAL SCIENCE JOURNAL, 88, 11, 1686, 1691, Nov. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Enhancement of sperm motility and viability by turmeric by-product dietary supplementation in roosters
  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, Oct. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Evolution of the sperm methylome of primates is associated with retrotransposon insertions and genome instability
  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, Sep. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Effects of semen preservation procedure in egg yolk-tris based extender on bull spermatozoa characteristics
  Chihiro Kanno; Yojiro Yanagawa; Yoshiyuki Takahashi; Seiji Katagiri; Masashi Nagano
  JAPANESE JOURNAL OF VETERINARY RESEARCH, 65, 3, 151, 157, Aug. 2017, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Comparison of sperm subpopulation structures in first and second ejaculated semen from Japanese black bulls by a cluster analysis of sperm motility evaluated by a CASA system
  Chihiro Kanno; Kentaro Q. Sakamoto; Yojiro Yanagawa; Yoshiyuki Takahashi; Seiji Katagiri; Masashi Nagano
  JOURNAL OF VETERINARY MEDICAL SCIENCE, 79, 8, 1359, 1365, Aug. 2017, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Relationship between in vitro growth of bovine oocytes and steroidogenesis of granulosa cells cultured in medium supplemented with bone morphogenetic protein-4 and follicle stimulating hormone
  Kenichiro Sakaguchi; Weiping Huang; Yinghua Yang; Yojiro Yanagawa; Masashi Nagano
  THERIOGENOLOGY, 97, 113, 123, Jul. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Estrous cycle stage-dependent manner of type I interferon-stimulated genes induction in the bovine endometrium.
  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, 21 Jun. 2017, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Endometrial epidermal growth factor profile and its abnormalities in dairy cows
  Seiji Katagiri; Masaharu Moriyoshi; Yojiro Yanagawa
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 62, 5, 465, 470, Oct. 2016, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• ターメリック製造副産物の給与がニワトリ精子運動能に及ぼす影響
  厳 文静; 菅野 智裕; 葛間 風花子; 大嶋 栄喜; 唄 花子; 高橋 昌志; 柳川 洋二郎; 永野 昌志; 若松 純一; 川原 学
  北海道畜産草地学会報, 4, 2, 26, 26, 北海道畜産草地学会, Aug. 2016
  Japanese
• Simultaneous evaluation of plasma membrane integrity, acrosomal integrity, and mitochondrial membrane potential in bovine spermatozoa by flow cytometry
  Chihiro Kanno; Sung-Sik Kang; Yasuyuki Kitade; Yojiro Yanagawa; Yoshiyuki Takahashi; Masashi Nagano
  ZYGOTE, 24, 4, 529, 536, Aug. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Conserved Roles of Fibroblast Growth Factor Receptor 2 Signaling in the Regulation of Inner Cell Mass Development in Bovine Blastocysts
  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, Jun. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Molecular identification of the Cryptosporidium deer genotype in the Hokkaido sika deer (Cervus nippon yesoensis) in Hokkaido, Japan
  Satomi Kato; Yojiro Yanagawa; Ryota Matsuyama; Masatsugu Suzuki; Chihiro Sugimoto
  PARASITOLOGY RESEARCH, 115, 4, 1463, 1471, Apr. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• The relationship between antral follicle count in a bovine ovary and developmental competence of in vitro-grown oocytes derived from early antral follicles
  Katsuhisa Nagai; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  BIOMEDICAL RESEARCH-TOKYO, 37, 1, 63, 71, 2016, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Mitochondrial activity during pre-maturational culture in in vitro-grown bovine oocytes is related to maturational and developmental competences
  Weiping Huang; Sung-Sik Kang; Katsuhisa Nagai; Yojiro Yanagawa; Yoshiyuki Takahashi; Masashi Nagano
  REPRODUCTION FERTILITY AND DEVELOPMENT, 28, 3, 349, 356, 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Expression dynamics of bovine MX genes in the endometrium and placenta during early to mid pregnancy.
  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, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Effect of bone morphogenetic protein-4 on in vitro growth, steroidogenesis and subsequent developmental competence of the oocyte-granulosa cell complex derived from bovine early antral follicles
  Yinghua Yang; Chihiro Kanno; Weiping Huang; Sung-Sik Kang; Yojiro Yanagawa; Masashi Nagano
  REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY, 14, Jan. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Fertilizability of oocytes derived from Holstein cows having different antral follicle counts in ovaries
  Katsuhisa Nagai; Yojiro Yanagawa; Seiji Katagiri; Masashi Nagano
  ANIMAL REPRODUCTION SCIENCE, 163, 172, 178, Dec. 2015, [Peer-reviewed]
  English, Scientific journal
• Comparing spatial expression dynamics of bovine blastocyst under three different procedures: in-vivo, in-vitro derived, and somatic cell nuclear transfer embryos
  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, Nov. 2015, [Peer-reviewed]
  English, Scientific journal
• ユキヒョウおよびホッキョクグマの尿道カテーテル挿入による精液採取
  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, 25 Jun. 2015, [Domestic magazines]
  Japanese
• カテーテル法を用いたホッキョクグマの採精と精液性状
  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, 25 Jun. 2015, [Domestic magazines]
  Japanese
• The efficacy of the well of the well (WOW) culture system on development of bovine embryos in a small group and the effect of number of adjacent embryos on their development
  Sung-Sik Kang; Sosuke Ofuji; Kei Imai; Weiping Huang; Keisuke Koyama; Yojiro Yanagawa; Yoshiyuki Takahashi; Masashi Nagano
  ZYGOTE, 23, 3, 412, 415, Jun. 2015, [Peer-reviewed]
  English, Scientific journal
• Addition of D-penicillamine, hypotaurine, and epinephrine (PHE) mixture to IVF medium maintains motility and longevity of bovine sperm and enhances stable production of blastocysts in vitro
  Sung-Sik Kang; Keisuke Koyama; Weiping Huang; Yinghua Yang; Yojiro Yanagawa; Yoshiyuki Takahashi; Masashi Nagano
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 61, 2, 99, 105, Apr. 2015, [Peer-reviewed]
  English, Scientific journal
• 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, Mar. 2015
  English
• Accessory corpora lutea formation in pregnant Hokkaido sika deer (Cervus nippon yesoensis) investigated by examination of ovarian dynamics and steroid hormone concentrations
  Yojiro Yanagawa; Yukiko Matsuura; Masatsugu Suzuki; Shin-ichi Saga; Hideto Okuyama; Daisuke Fukui; Gen Bando; Masashi Nagano; Seiji Katagiri; Yoshiyuki Takahashi; Toshio Tsubota
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 61, 1, 61, 66, Feb. 2015, [Peer-reviewed]
  English, Scientific journal
• 分娩後のホルスタイン種への黒毛和種精漿の投与効果
  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, Jan. 2015, [Domestic magazines]
  Japanese
• ホルスタイン種リピートブリーダー牛に対する黒毛和種精漿注入の効果
  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], Dec. 2014
  Japanese, 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。
• Effects of ovarian storage condition on in vitro maturation of Hokkaido sika deer (Cervus nippon yesoensis) oocytes
  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, Nov. 2014, [Peer-reviewed]
  English, Scientific journal
• Effects of in vitro-growth culture duration on fertilizability of bovine growing oocytes and proliferation of cells surrounding oocytes
  Weiping Huang; Sung-Sik Kang; Yojiro Yanagawa; Yinghua Yang; Yoshiyuki Takahashi; Masashi Nagano
  JAPANESE JOURNAL OF VETERINARY RESEARCH, 62, 3, 135, 141, Aug. 2014, [Peer-reviewed]
  English, Scientific journal
• Estimation of the Optimal Timing of Fertilization for Embryo Development of In Vitro-Matured Bovine Oocytes Based on the Times of Nuclear Maturation and Sperm Penetration
  Keisuke Koyama; Sung-Sik Kang; Weiping Huang; Yojiro Yanagawa; Yoshiyuki Takahashi; Masashi Nagano
  JOURNAL OF VETERINARY MEDICAL SCIENCE, 76, 5, 653, 659, May 2014, [Peer-reviewed]
  English, Scientific journal
• Aging-related Changes in In Vitro-matured Bovine Oocytes: Oxidative Stress, Mitochondrial Activity and ATP Content After Nuclear Maturation
  Keisuke Koyama; Sung-Sik Kang; Weiping Huang; Yojiro Yanagawa; Yoshiyuki Takahashi; Masashi Nagano
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 60, 2, 136, 142, Apr. 2014, [Peer-reviewed]
  English, Scientific journal
• Changes in the Immunolocalization of Steroidogenic Enzymes and the Androgen Receptor in Raccoon (Procyon lotor) Testes in Association with the Seasons and Spermatogenesis
  Minami W. Okuyama; Michito Shimozuru; Yojiro Yanagawa; Toshio Tsubota
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 60, 2, 155, 161, Apr. 2014, [Peer-reviewed]
  English, Scientific journal
• An attempt to induce antibody production for immunocontraception in the Hokkaido sika deer (Cervus nippon yesoensis) by immunization with a porcine zona pellucida synthetic peptide
  Kohei Kobayashi; Makoto Asano; Yojiro Yanagawa; Singo Haneda; Motozumi Matsui
  MAMMAL STUDY, 39, 1, 59, 64, Mar. 2014, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Prematurational Culture with 3-Isobutyl-1-methylxanthine Synchronizes Meiotic Progression of the Germinal Vesicle Stage and Improves Nuclear Maturation and Embryonic Development in In Vitro-grown Bovine Oocytes
  Weiping Huang; Masashi Nagano; Sung-Sik Kang; Yojiro Yanagawa; Yoshiyuki Takahashi
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 60, 1, 9, 13, Feb. 2014, [Peer-reviewed]
  English, Scientific journal
• 野生動物の繁殖制限と避妊法 (特集 動物園における希少動物の繁殖と生殖補助技術(後編))
  栁川 洋二郎
  獣医畜産新報, 67, 1, 33, 35, 文永堂出版, Jan. 2014, [Domestic magazines]
  Japanese
• In vitro maturation system for individual culture of bovine oocytes using micro-volume multi-well plate.
  Masashi Nagano; Sung-Sik Kang; Keisuke Koyama; Weiping Huang; Yojiro Yanagawa; Yoshiyuki Takahashi
  The Japanese journal of veterinary research, 61, 4, 149, 54, Nov. 2013, [Peer-reviewed], [Domestic magazines]
  English, Scientific journal
• Effects of in vitro growth culture duration and prematuration culture on maturational and developmental competences of bovine oocytes derived from early antral follicles
  Weiping Huang; Masashi Nagano; Sung-Sik Kang; Yojiro Yanagawa; Yoshiyuki Takahashi
  THERIOGENOLOGY, 80, 7, 793, 799, Oct. 2013, [Peer-reviewed]
  English, Scientific journal
• The effects of frequent electroejaculation on the semen characteristics of a captive siberian tiger (Panthera tigris altaica)
  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, [Peer-reviewed]
  English, Scientific journal
• Fetal Age Estimation of Hokkaido Sika Deer (Cervus nippon yesoensis) Using Ultrasonography During Early Pregnancy
  Yojiro Yanagawa; Yukiko Matsuura; Masatsugu Suzuki; Shin-ichi Saga; Hideto Okuyama; Daisuke Fukui; Gen Bandou; Seiji Katagiri; Yoshiyuki Takahashi; Toshio Tsubota
  JOURNAL OF REPRODUCTION AND DEVELOPMENT, 55, 2, 143, 148, Apr. 2009, [Peer-reviewed]
  English, Scientific journal
• Immunohistochemical localization of the estrogen receptor alpha (ER alpha) and progesterone receptor (PR) in the uterus of sika deer (Cervus nippon) during pregnancy
  Yojiro Yanagawa; Yukiko Matsuura; Masatsugu Suzuki; Seiji Katagiri; Toshio Tsubota
  JAPANESE JOURNAL OF VETERINARY RESEARCH, 56, 3, 139, 149, Nov. 2008, [Peer-reviewed]
  English, Scientific journal
• Effect of a tranquilizer on stress control in birds under restraint
  Yanagawa Y; Suzuki K
  Biosphere Conservation, 6, 2, 55, 59, 2004, [Peer-reviewed]
  English, Scientific journal

• Mating strategies to identification with the gestation of Alpacas
  荒古江美紗; 柳川洋二郎; 西村亮; 山本直樹; 菅野智裕; 片桐成二; 桃沢健二; 永野昌志, 日本野生動物医学会大会・講演要旨集, 30th, 2024
• Artificial insemination and ovulation induction performed based on natural mating in polar bear
  柳川洋二郎; 鳥居佳子; 鳥居佳子; 永野昌志; 曽地千尋; 田中紘子; 入江陽一; 吉住和規; 橋本渉; 三浦史順; 高橋一斗; 山崎槙; 大崎彩佳; 楠田哲士; 片桐成二, 日本野生動物医学会大会・講演要旨集, 30th, 2024
• Novel method for evaluating capacitation ability of bovine sperm using oviductal epithelial cells and evaluation of sex sorted sperm function (II)
  柳川洋二郎; 菅野智裕, 食肉に関する助成研究調査成果報告書, 37, 2019
• Novel method for evaluating capacitation ability of bovine sperm using oviductal epithelial cells and evaluation of sex sorted sperm function
  柳川洋二郎; 永野昌志, 食肉に関する助成研究調査成果報告書, 36, 178‐182, Nov. 2018
  Japanese
• 乳牛の卵巣内胞状卵胞数が血中卵胞刺激ホルモン動態と卵胞における性ステロイドホルモン産生に与える影響
  坂口謙一郎; 柳川洋二郎; 吉岡耕治; 須田智子; 植芝滉己; 河野光平; 宮本祥代; 片桐成二; 永野昌志, 日本獣医学会学術集会講演要旨集, 161st, 2018
• ヒグマ精液の凍結保存液に添加する糖の種類および冷却速度が凍結融解後の精液性状に及ぼす影響
  鳥居佳子; 菅野智裕; 蓑原悠太朗; 坂元秀行; 松本直也; 冨安洵平; 松井基純; 永野昌志; 片桐成二; 柳川洋二郎, 日本獣医学会学術集会講演要旨集, 160th, 440, 440, 30 Aug. 2017
  (公社)日本獣医学会, Japanese
• ペレット法による凍結保存が融解後のニホンザル精液の運動性に与える影響
  柳川 洋二郎; 菅野 智裕; 兼子 明久; 印藤 頼子; 岡本 宗裕; 片桐 成二; 永野 昌志, 日本獣医学会学術集会講演要旨集, 159回, 431, 431, Aug. 2016
  (公社)日本獣医学会, Japanese
• ニホンザルにおける電気刺激時の電圧が精子採取に与える影響および精子凍結保存法の改善について
  杉本 幸介; 柳川 洋二郎; 菅野 智裕; 高江洲 昇; 兼子 明久; 印藤 頼子; 岡本 宗裕; 片桐 成二; 永野 昌志, 日本獣医学会学術集会講演要旨集, 158回, 381, 381, Aug. 2015
  (公社)日本獣医学会, Japanese
• ネコ目動物3種における尿道カテーテル挿入による精子採取
  高江洲昇; 伊藤真輝; 菅原里沙; 柳川洋二郎; 永野昌志; 佐鹿万里子; 下鶴倫人; 坪田敏男, 日本獣医学会学術集会講演要旨集, 157th, 547, 547, 11 Aug. 2014
  (公社)日本獣医学会, Japanese
• ウシ子宮内膜組織におけるMX1とMX1B発現に及ぼすI型インターフェロンの応答性およびその受容体の発情周期別比較
  白水貴大; 川原学; 木村康二; 高橋ひとみ; 柳川洋二郎; 永野昌志; 白汝嵐; 今川和彦; 高橋昌志, Journal of Reproduction and Development, 107, 0, OR2, 24-OR2-24, 2014
  【目的】ウシMX1はI型インターフェロン(IFN)-α/β誘導性遺伝子であり，MX1Bというスプライシング変異体が存在する。我々は第2回北海道畜産草地学会において，子宮組織におけるMX1とMX1B mRNAが妊娠中期と比べて妊娠初期で有意に高い発現を示すことを報告した。このことから，MX1とMX1Bの発現には，妊娠認識時にのみ胚より産生されるIFN-τが深く関わることが示唆された。IFN-τはI型IFNに属するが，IFN-α/βとは異なる一過性の産生パターンを示す。本研究では，MX1とMX1BのI型IFN応答性差異の有無を明らかにする目的で，ウシ子宮組織培養系を用いてIFN-τまたはIFN-αによるMX1とMX1B mRNAの発現応答を比較し検証した。さらに，発情周期の違いによる両遺伝子のIFN応答性の差異について，I型IFN受容体発現と併せて検証した。【材料と方法】黄体所見をもとに前期，中期，後期に分けた食肉処理場由来のウシ非妊娠子宮から内膜組織を採取した。これらの組織小片を1時間前培養後，抗ウイルス活性を合わせたIFN-τを含む濃縮妊娠子宮灌流液(D18)またはウシ組換えIFN-α添加で培養し，12および24時間後のMX1とMX1B mRNAの発現量を定量PCRで調べた。また，採取直後の子宮組織におけるI型IFN受容体IFNAR1とIFNAR2の発現量も定量PCRで調べた。【結果と考察】子宮灌流液(D18)またはIFN-α添加によってMX1とMX1Bともに発現が誘導され，MX1Bに対しMX1が有意に高い発現量を示したが，両添加区間で応答性に差はみられなかった。発情周期別で比較した結果，12時間培養後のMX1とMX1Bの発現量ならびに採取直後の子宮組織でのIFNAR1とIFNAR2の発現量は後期で低い傾向がみられた。以上より，発情周期の違いで子宮内膜におけるI型IFN受容体の発現量が変化し，それに伴いI型IFNによるMX1とMX1Bの発現応答性に差異が生じる可能性が示唆された。, 日本繁殖生物学会, Japanese
• エゾシカの発達および性成熟過程における卵胞形成と卵胞でのステロイド合成能
  小林すみよ; 柳川洋二郎; 坪田敏男; 永野昌志, 日本野生動物医学会大会・講演要旨集, 19th, 95, 2013
  Japanese

• 哺乳類学の百科事典 = Encyclopedia of mammalogy
  日本哺乳類学会
  丸善出版, Nov. 2025, 9784621311967, xiii, 513p, 図版16p(ページ付なし), Japanese
• 獣医繁殖学マニュアル
  獣医繁殖学教育協議会
  文永堂出版, Mar. 2025, 9784830032943, xiv, 305p, Japanese
• 獣医繁殖学
  大澤, 健司; 片桐, 成二; 田中, 知己; 獣医繁殖学教育協議会
  文永堂出版, Sep. 2023, 9784830032882, xxiv, 475p, Japanese
• 霊長類学の百科事典 = The encyclopedia of primatology
  日本霊長類学会
  丸善出版, Jul. 2023, 9784621308042, xxii, 716p, 図版 [8] p, Japanese
• 増補版野生動物管理 -理論と技術-
  柳川 洋二郎, 第22章 繁殖状態評価法
  文永堂出版, 2016, 311-327, Japanese, Textbook, [Joint work]
• 動物園動物管理学
  柳川 洋二郎, 第34章 余剰動物対策のための避妊
  文永堂出版, 2014, [Joint work]
• 野生動物管理
  柳川 洋二郎, 第20章 繁殖状態評価法
  文永堂出版, May 2012, [Joint work]

• 妊娠に伴うヒグマ母体免疫の変化～時系列及び妊娠・偽妊娠間の末梢血での発現比較～
  西島明日香; 栁川洋二郎; 松本直也; 萩野恭伍; 坂本秀行; 早川卓志
  第73回日本生態学会大会, 15 Mar. 2026
• Evaluation of STLV-1 in the semen of infected Japanese macaques
  Maureen Kidiga; Poonam Grover; Yojiro Yanagawa; Sakura Hayashi; Hirotaka Ode; Yasumasa Iwatani; Mayumi Morimoto; Takayoshi Natsume; Akihisa Kaneko; Takuo Mizukami; Hirofumi Akari
  第11回日本HTLV-1学会学術集会, 08 Nov. 2025
• 雌チンパンジーにおける合成ジェスタージェン製剤による繁殖抑制効果と製剤切替の影響の評価
  小谷真智子; 平栗明実; 宮部貴子; 兼子明久; 足立幾磨; 片桐成二; 栁川洋二郎
  第31回日本野生動物医学会大会, 27 Sep. 2025
• 雌シマオイワワラビーにおける繁殖ステージの変化に伴う末梢血白血球における遺伝子発現変動
  小林茉利奈; 西島明日香; 高橋能理子; 二井綾子; 早川卓志; 片桐成二; 栁川洋二郎
  第31回日本野生動物医学会大会, 27 Sep. 2025
• シロテテナガザルにおいて性腺刺激ホルモン放出ホルモン作動薬の徐放型インプラント投与により繁殖抑制を試みた2症例
  對馬隆介; 木村嘉孝; 大田早月; 田丸正枝; 鷹羽理乃; 吉田淳一; 佐渡晃浩; 片桐成二; 栁川洋二郎
  第31回日本野生動物医学会大会, 27 Sep. 2025
• 牛の腟内に投与されることで子宮機能を調節するオステオポンチン部分ペプチドが培養下の腟組織における炎症性サイトカイン遺伝子発現に及ぼす影響
  谷田孝志; 栁川洋二郎; 片桐成二
  第118回日本繁殖生物学会大会, Oral presentation
  15 Sep. 2025 - 17 Sep. 2025
• 上畑 祐樹, 坂口 謙一郎, 斎藤 萌佳, 谷田 孝志, 栁川 洋二郎, 片桐 成二, 木村 康二, 河野 光平
  ウシ未成熟卵子の輸送条件の確立のための保持温度の検討
  日本畜産学会第133回大会, 12 Sep. 2025
  15 Sep. 2025
• グリセリン添加および冷却がスマトラオランウータンの精液性状に及ぼす影響の予備的検討
  對馬隆介; 小谷真智子; 村上郁; 里永萌; 濱田純基; 井上依里子; 中山晃子; 片桐成二; 栁川洋二郎
  第168回日本獣医学会学術集会, 05 Sep. 2025
• A Toll-like receptor 4-mediated regulation of EGF production in the bovine uterine cell by palmitic acid
  Mwandabantu M.; Sakaguchi k; Saito M.; Nunez HJC; Tadeo R.; Tanida T.; Yanagawa Y.; Katagiri S.
  第168回日本獣医学会学術集会, 05 Sep. 2025
• 北海道産4種のトガリネズミ類の繁殖状況の季節変動について（予報）
  谷川弘樹; 佐藤陽子; 鳥居佳子; 本田直也; 小林木野実; 飯島なつみ; 松本直也; 栁川洋二郎; 大舘智志
  日本哺乳類学会2025年度大会, 23 Aug. 2025
• 不受胎牛摘発のための乳汁中プロジェステロン濃度測定
  柳川洋二郎; 杉浦智親; 石田晃彦; 渡慶次学; 片桐成二
  日本獣医学会学術集会講演要旨集, 2024
  2024 - 2024
• めん羊の発情同期化に用いる腟内プロジェステロン徐放剤処置が人工授精時の腟内細菌叢に与える影響
  齋藤希実; 佐川里子; 白鳥麗奈; 健山幸乃; 鈴木康規; 久保田寛顕; 谷田孝志; 柳川洋二郎; 片桐成二; 菅野智裕; 桃沢健二; 永野昌志
  東北畜産学会報, 2024
  2024 - 2024
• ヒグマ皮膚腺由来オルガノイドの樹立に向けた試み
  小林良祐; 萩野恭伍; 髙橋なるみ; 髙橋直紀; 渡邉敬文; 栁川洋二郎; 冨安洵平
  第48回日本分子生物学会年会, 04 Dec. 2023
• Comparison of gestagens concentrations measured by two different methods in Elephantidae and characterization of gestagens dynamics in cyclic Asian elephants (Elephas maximus)
  Katagiri T.; Matsui M.; Ikenaka Y.; Nakagawa D.; Kamada Y.; Yoshida S.; Sochi C.; Kusuda S.; Katagiri S.; Yanagawa Y.
  The 13th Sapporo Summer Symposium for One Health, 25 Sep. 2023
• Effects of osteopontin treatment outside the day of estrus on normalization of EGF concentration and fertility
  Chijikwa JB; Tanida T.; Sakaguchi K.; Sugiura T.; Yanagawa Y.; Katagir S.
  第168回日本獣医学会学術集会, 05 Sep. 2023
• 乳牛の分娩前の体温低下,ホルモン動態および分娩経過の関連について
  亀谷牧子; 古川瑛理; 古川瑛理; 池中良徳; 松崎明; 柳川洋二郎; 片桐成二
  日本獣医学会学術集会講演要旨集, 2023
  2023 - 2023
• 乳用牛の発情後期および発情休止期における耐糖能の違い
  谷田孝志; 池田侑樹; 田嶋彩野; 田嶋彩野; 菅野智裕; 菅野智裕; 坂口謙一郎; 柳川洋二郎; 永野昌志; 永野昌志; 片桐成二
  日本獣医学会学術集会講演要旨集, 2023
  2023 - 2023
• 生理的な範囲の暑熱負荷が牛初期胞状卵胞由来卵子の発生能および抗酸化能に及ぼす影響
  河野光平; 坂口謙一郎; 坂口謙一郎; CHELENGA Madalitso; NATTAPONG Ninpetch; 小林進太郎; 古川瑛理; 柳川洋二郎; 片桐成二
  日本生殖医学会雑誌, 2022
  2022 - 2022
• ルーメンセンサから得られる温度データの機械学習による乳牛の分娩予測
  古川瑛理; 檜垣彰吾; 松崎明; 唄花子; 高橋昌志; 片桐成二; 柳川洋二郎
  日本畜産学会大会講演要旨, 2022
  2022 - 2022
• 乳牛の血漿遊離脂肪酸濃度上昇に伴う卵子エネルギー代謝関連脂質プロファイルの変化
  古川瑛理; 陳震; 窪友瑛; CHELENGA Madalitso; WU Yue; 千葉仁志; 柳川洋二郎; 片桐成二; 惠淑萍; 永野昌志
  日本生殖医学会雑誌, 2022
  2022 - 2022
• 暑熱負荷が牛の初期胞状卵胞に由来する卵子中の活性酸素種および還元型グルタチオン量に及ぼす影響
  河野光平; 坂口謙一郎; 坂口謙一郎; CHELENGA Madalitso; 古川瑛理; NINPETCH Nattapong; 柳川洋二郎; 片桐成二
  日本繁殖生物学会講演要旨集(Web), 2021
  2021 - 2021
• 第二胃内留置型自動体温測定器で測定したホルスタイン種経産牛の分娩前1週間の体温変化と分娩時間帯の関係
  古川瑛理; 高橋昌志; 松崎明; 唄花子; 永野昌志; 片桐成二; 柳川洋二郎
  日本畜産学会大会講演要旨, 2021
  2021 - 2021
• 液体クロマトグラフィー質量分析法によるアフリカゾウの血中ステロイドホルモン濃度測定法の確立および無排卵雌における排卵誘起の試み
  篠原明; 篠原明; 鳥居佳子; 入江陽一; 牛尾佳名子; 曽地千尋; 宗内一平; 楠田哲士; 東達也; 一瀬貴大; 中山翔太; 石塚真由美; 池中良徳; 片桐成二; 柳川洋二郎
  日本獣医学会学術集会講演要旨集, 2021
  2021 - 2021
• Expression and functional analysis of swine PD-1 /PD-L1 pathway
  OTGONTUYA Ganbaatar; 今内覚; 岡川朋弘; 野島裕太郎; 前川直也; 市川世識; 小林篤史; 芝原友幸; 柳川洋二郎; 鈴木定彦; 村田史郎; 大橋和彦
  日本獣医学会学術集会講演要旨集, 2021
  2021 - 2021
• Risk factors for altered endometrial Epidermal Growth Factor (EGF) recovery and subsequent fertility in dairy cows
  NATTAPONG Ninpetch; 河野光平; 柳川洋二郎; 片桐成二
  日本獣医学会学術集会講演要旨集, 2021
  2021 - 2021
• ホルスタイン種泌乳牛の分娩後日数及びボディコンディションスコアと卵子中トリアシルグリセロール量の関係
  古川瑛理; 陳震; 窪友瑛; MADALITSO Chelenga; YUE Wu; 千葉仁志; 柳川洋二郎; 片桐成二; 惠淑萍; 永野昌志
  日本獣医学会学術集会講演要旨集, 2021
  2021 - 2021
• マクロファージのユビキチン特異的プロテアーゼ2が凍結精子の機能に与える役割
  橋本茉由子; 木村俊介; 菅野智裕; 柳川洋二郎; 渡邉敬文; 高橋英機; 永野昌志; 北村浩
  日本獣医学会学術集会講演要旨集, 2021
  2021 - 2021
• 乳汁中プロジェステロン濃度測定による発情回帰牛の摘発
  古川瑛理; 安田奈絵; 山田淑子; 石田晃彦; 渡慶次学; 渡邊龍之介; 篠原禎忠; 松田憲司; 野内繁広; 片桐成二; 柳川洋二郎
  日本獣医学会学術集会講演要旨集, 2020
  2020 - 2020
• Astaxanthin supplementation during IVG culture under different oxygen tensions promotes developmental competence of bovine oocytes derived from early antral follicles.
  CHELENGA Madalitso; 坂口謙一郎; 坂口謙一郎; 古川瑛理; 柳川洋二郎; 片桐誠二; 永野昌志
  日本獣医学会学術集会講演要旨集, 2020
  2020 - 2020
• 暑熱が乳牛の初期胞状卵胞に由来する卵子の発育,成熟および顆粒層細胞の性ステロイドホルモン産生能に及ぼす影響
  河野光平; 坂口謙一郎; 坂口謙一郎; 古川瑛理; CHELENGA Madalitso; 柳川洋二郎; 片桐成二
  日本獣医学会学術集会講演要旨集, 2020
  2020 - 2020
• 精漿が豚の末梢血単核球中のサイトカイン発現および制御性T細胞に与える影響
  阪井紀乃; 奥山みなみ; 奥山みなみ; 對馬隆介; 對馬隆介; 南家夕子; 篠原明; 古川瑛理; 河野光平; 柳川洋二郎; 楢原久司; 片桐成二
  日本獣医学会学術集会講演要旨集, 2020
  2020 - 2020
• Brown bear hair growth and application for the ecological study on wild brown bears
  神保美渚; 松本直也; 坂元秀行; 石名坂豪; 柳川洋二郎; 鳥居佳子; 白根ゆり; 佐鹿万里子; 坪田敏男; 下鶴倫人
  日本生態学会大会講演要旨(Web), 2020
  2020 - 2020
• 精巣マクロファージのユビキチン特異的プロテアーゼ2が精子機能に与える影響
  橋本茉由子; 木村俊介; 菅野智裕; 菅野智裕; 柳川洋二郎; 渡邉敬文; 岡部潤; 高橋英機; 永野昌志; 北村浩
  日本分子生物学会年会プログラム・要旨集(Web), 2020
  2020 - 2020
• 組み換えオステオポンチンによる牛子宮内膜上皮成長因子濃度の正常化効果の検証
  佐藤弘子; KYAW Hay Mar; 柳川洋二郎; 永野昌志; 田上貴祥; 片桐成二
  Journal of Reproduction and Development, 05 Sep. 2019, Japanese
  05 Sep. 2019 - 05 Sep. 2019
• Identification of seminal plasma proteins to normalize endometrial epidermal growth factor concentrations in repeat breeder cows
  BADRAKH Dagvajamts; 柳川洋二郎; 永野昌志; 片桐成二
  日本獣医学会学術集会講演要旨集, 20 Aug. 2019, English
  20 Aug. 2019 - 20 Aug. 2019
• 乳牛の子宮内膜組織血流量に影響を及ぼす因子の解析
  河野光平; 柳川洋二郎; NATTAPONG Ninpetch; 永野昌志; 片桐成二
  日本獣医学会学術集会講演要旨集, 20 Aug. 2019, Japanese
  20 Aug. 2019 - 20 Aug. 2019
• クマ科動物の人工授精技術の開発に向けた研究
  鳥居佳子; 永野昌志; 片桐成二; 柳川洋二郎
  日本獣医学会学術集会講演要旨集, 20 Aug. 2019, Japanese
  20 Aug. 2019 - 20 Aug. 2019
• 牛性選別精子の卵管上皮細胞結合能および受精能獲得のフローサイトメトリーによる解析
  中島愛理; 菅野智裕; 菅野智裕; 片桐成二; 永野昌志; 柳川洋二郎
  日本獣医学会学術集会講演要旨集, 20 Aug. 2019, Japanese
  20 Aug. 2019 - 20 Aug. 2019
• ニホンザルにおけるプロジェステロン作動薬による月経周期同期化
  黒澤拓斗; 黒澤拓斗; 兼子明久; 夏目尊好; 森本真弓; 愛洲星太郎; GRIS Vanessa; TAKESHITA Rafaela Sayuri; 宮部貴子; 岡本宗裕; 永野昌志; 片桐成二; 柳川洋二郎
  日本野生動物医学会大会・講演要旨集, 2019
  2019 - 2019
• 性腺刺激ホルモン製剤を投与したチーターにおける糞中の性ホルモン動態からみた発情・排卵誘起状況の検証
  松原香菜; 松原香菜; 楠田哲士; 楠田哲士; 東野晃典; 植田美弥; 野村美佳; 緒形倫子; 有馬一; 尾形光昭; 市野瀬碧; 大沼友有子; 土井守; 土井守; 柳川洋二郎; 永野昌志
  日本野生動物医学会大会・講演要旨集, 2019
  2019 - 2019
• 捕獲ストレスに着目したエゾシカの肉質評価の試み
  亀井利活; 稲富佳洋; 宇野裕之; 桑子和洋; 若松純一; 柳川洋二郎; 近藤誠司
  日本哺乳類学会大会プログラム・講演要旨集, 08 Sep. 2018, Japanese
  08 Sep. 2018 - 08 Sep. 2018
• モンゴル国における羊体外受精卵由来産子作出の試み：体外成熟培地への抗酸化剤アスタキサンチンの添加効果
  永野昌志; Purevdorj Erdenetogtokh; 栁川洋二郎; 片桐成二
  北海道牛受精卵移植研究会会報, Sep. 2018, Japanese
  Sep. 2018 - Sep. 2018
• Lipidomic profiling in bovine oocytes by LC/Orbitrap-MS
  WU Yue; UESHIBA Hiroki; CHEN Zhen; SAKAGUCHI Kenichiro; YANAGAWA Yojiro; KATAGIRI Seiji; NAGANO Masashi; CHIBA Hitoshi; CHIBA Hitoshi; HUI Shu‐Ping
  JSBMS Letters, 25 Aug. 2018, English
  25 Aug. 2018 - 25 Aug. 2018
• 液体クロマトグラフィー高分解能質量分析を用いた牛卵子中遊離脂肪酸およびトリアシルグリセロールの分析
  植芝滉己; 呉ユエ, 陳震; 坂口謙一郎; 柳川洋二郎; 片桐成二; 千葉仁志; 千葉仁志; 惠淑萍; 永野昌志
  日本獣医学会学術集会講演要旨集, 21 Aug. 2018, Japanese
• 乳牛の卵巣内胞状卵胞数が血中卵胞刺激ホルモン動態と卵胞における性ステロイドホルモン産生に与える影響
  坂口謙一郎; 柳川洋二郎; 吉岡耕治; 須田智子; 植芝滉己; 河野光平; 宮本祥代; 片桐成二; 永野昌志
  日本獣医学会学術集会講演要旨集, 21 Aug. 2018, Japanese
• ホルスタイン種未経産牛の妊娠中血中テストステロン濃度と産子の卵巣予備能および母体の健康状態との関連性
  古山敬祐; 柳川洋二郎; 小山毅; 窪友瑛; 杉本昌仁
  日本獣医学会学術集会講演要旨集, 21 Aug. 2018, Japanese
• 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
  菅野智裕; 菅野智裕; 柳川洋二郎; 片桐成二; 永野昌志
  日本獣医学会学術集会講演要旨集, 21 Aug. 2018, Japanese
• マクロファージ選択的ユビキチン特異的プロテアーゼ2欠損マウスの精巣機能の評価
  天笠美聡; 菅野智裕; 木村俊介; 柳川洋二郎; 岩永敏彦; 高橋英機; 永野昌志; 北村浩
  日本獣医学会学術集会講演要旨集, 21 Aug. 2018, Japanese
• 乳牛における暑熱ストレスと子宮内膜中上皮成長因子濃度異常との関係および暑熱の子宮内環境への影響評価のための子宮内温度と子宮内膜血流量の測定法の検討
  河野光平; 柳川洋二郎; NATTAPONG Ninpetch; 坂口謙一郎; 菅野智裕; 菅野智裕; 鳥居佳子; 植芝滉己; 宮本祥代; 永野昌志; 片桐成二
  日本獣医学会学術集会講演要旨集, 21 Aug. 2018, Japanese
• 卵胞刺激ホルモンおよび性腺刺激ホルモン放出ホルモン投与による卵巣刺激が河川型水牛 (Bubalus bubalis) における経腟採卵-体外受精成績に及ぼす影響
  坂口謙一郎; Excel Rio S. Maylem; Ramesh C. Tilwani; 栁川洋二郎; 片桐成二; Edwin C. Atabay; Eufrocina P. Atabay; 永野昌志
  北海道牛受精卵移植研究会会報, Aug. 2018, Japanese
  Aug. 2018 - Aug. 2018
• マクロファージに選択的なUsp2ノックアウトマウスの精巣機能の評価
  天笠美聡; 菅野千裕; 木村俊介; 柳川洋二郎; 高橋英機; 永野昌志; 北村浩
  日本分子生物学会年会プログラム・要旨集(Web), 2018
  2018 - 2018
• 冬眠を経た雄成獣エゾヒグマ(Ursus arctos yesoensis)のボディコンディションと精巣機能の変化
  林優季; 冨安洵平; 羽田真悟; 松本直也; 柳川洋二郎; 佐々木和好; 松井基純
  日本野生動物医学会大会・講演要旨集, 2018
  2018 - 2018
• ペレット法により凍結したニホンザル精液に対する融解法の違いが精子性状に与える影響
  栁川洋二郎; 菅野智裕; 兼子明久; 印藤頼子; 佐藤容; 木下こづえ; 今井啓雄; 平井啓久; 片桐成二; 永野昌志; 岡本宗裕
  Cryopreservation conference 2017, Nov. 2017, Japanese
  Nov. 2017 - Nov. 2017
• Difference in antral follicle count of daughters and testosterone concentration during pregnancy between heifers and lactating cows
  K Koyama; Y Yanagawa; T Koyama; Y Matsui; N Kusakari; M Sugimoto
  Proceedings of the fourth world congress of reproductive biology, Sep. 2017
  Sep. 2017 - Sep. 2017
• 黒毛和種リピートブリーダー牛の子宮内膜上皮成長因子発現異常に対する治療への抵抗性と肥満との関係
  谷田孝志; 谷田孝志; 坂口謙一郎; 菅野智裕; 池田侑樹; 田嶋彩野; 柳川洋二郎; 永野昌志; 片桐成二
  日本獣医学会学術集会講演要旨集, 30 Aug. 2017, Japanese
  30 Aug. 2017 - 30 Aug. 2017
• 精子運動能自動解析装置(CASA)を用いた受精能獲得精子の運動性評価
  菅野智裕; 柳川洋二郎; 片桐成二; 永野昌志
  日本獣医学会学術集会講演要旨集, 30 Aug. 2017, Japanese
  30 Aug. 2017 - 30 Aug. 2017
• 交配および妊娠が豚の末梢血単核球中のサイトカイン発現および制御性T細胞に与える影響
  池田侑樹; 奥山みなみ; 奥山みなみ; 森好政晴; 山田未知; 杉浦智親; 柳川洋二郎; 永野昌志; 片桐成二
  日本獣医学会学術集会講演要旨集, 30 Aug. 2017, Japanese
  30 Aug. 2017 - 30 Aug. 2017
• ヒグマ精液の凍結保存液に添加する糖の種類および冷却速度が凍結融解後の精液性状に及ぼす影響
  鳥居佳子; 菅野智裕; 蓑原悠太朗; 坂元秀行; 松本直也; 冨安洵平; 松井基純; 永野昌志; 片桐成二; 柳川洋二郎
  日本獣医学会学術集会講演要旨集, 30 Aug. 2017, (公社)日本獣医学会, Japanese
  30 Aug. 2017 - 30 Aug. 2017
• 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
  坂口謙一郎; 谷田孝志; 谷田孝志; 楊応華; 菅野智裕; 永井克尚; 永井克尚; MOHAMED. A. Abdel‐Ghani; 柳川洋二郎; 片桐成二; 永野昌志
  日本獣医学会学術集会講演要旨集, 30 Aug. 2017, Japanese
  30 Aug. 2017 - 30 Aug. 2017
• ニホンザルにおける排卵誘起処置を伴う単回人工授精プログラムの検討
  柳川洋二郎; 菅野智裕; 南晶子; 兼子明久; 印藤頼子; 佐藤容; 木下こづえ; 岡本宗裕; 片桐成二; 永野昌志
  日本獣医学会学術集会講演要旨集, 30 Aug. 2017, Japanese
  30 Aug. 2017 - 30 Aug. 2017
• Mitochondrial activity and reactive oxygen species(ROS) accumulation in bovine oocytes derived from different culture system for in vitro maturation(和訳中)
  Purevdorj Erdenetogtokh; 柳川 洋二郎; 片桐 成二; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2017, (公社)日本獣医学会, English
  Aug. 2017 - Aug. 2017
• 牛卵巣の大きさが顆粒層細胞の性ステロイドホルモン産生能および卵子核成熟能に与える影響
  坂口 謙一郎; 菅野 智裕; 楊 応華; 柳川 洋二郎; 片桐 成二; 永野 昌志
  北海道獣医師会雑誌, Aug. 2017, (公社)北海道獣医師会, Japanese
  Aug. 2017 - Aug. 2017
• ヤクシカにおける糞中性ステロイドホルモン濃度の季節変化―エゾシカと比較して―
  木下こづえ; 揚妻(柳原)芳美; 揚妻直樹; 杉浦秀樹; 半谷吾郎; 早川卓志; 柳川洋二郎
  日本野生動物医学会大会・講演要旨集, 2017, Japanese
• 飼育下アフリカゾウ1個体から採取した精液の輸送後および凍結融解後の精子性状
  鳥居佳子; 菅野智裕; 曽地千尋; 宗内一平; 牛尾佳名子; 吉住和規; 千田圭; 橋本渉; 永野昌志; 片桐成二; 柳川洋二郎
  日本野生動物医学会大会・講演要旨集, 2017, Japanese
• 内視鏡を用いたヒグマ(Ursus arctos)における子宮内授精の試み
  柳川洋二郎; 鳥居佳子; 菅野智裕; 田嶋彩野; 冨安洵平; 松本直也; 坂元秀行; 亀井利活; 間野勉; 片桐成二; 永野昌志
  日本野生動物医学会大会・講演要旨集, 2017, Japanese
• 発情期及び妊娠認識時のウシ子宮組織におけるオートファジー カテプシン関連因子の発現動態
  鈴木 惇文; 白水 貴大; 岩野 弘暉; 小木曽 貴季; 山内 伸彦; 柳川 洋二郎; 永野 昌志; 唄 花子; 川原 学; 高橋 昌志
  The Journal of Reproduction and Development, Sep. 2016, (一社)日本繁殖生物学会, Japanese
  Sep. 2016 - Sep. 2016, 【目的】ウシの子宮組織機能は発情周期及び着床期において絶えず変化している。特に，受精後14–18日では胚からIFN-τが分泌され，黄体退行が阻止されることで妊娠が維持される。そのため，この期間は妊娠認識とともに着床・妊娠の準備のための期間でもある。細胞内のタンパク質分解・再利用に関わるオートファジー機構は異化，細胞増殖，分化など，細胞内の代謝・環境変化に関わることが知られている。生殖組織においても，ステロイドホルモン依存的なオートファジー動態の変化がマウス子宮組織で見られる。しかし，ウシにおいては，オートファジーと子宮組織との関わりは未解明である。そこで，本研究では発情周期及び着床前期のウシ子宮組織におけるオートファジー及び，関連の深いリソソームカテプシンの動態を明らかにすることを目的とした。【方法】食肉検査場由来のウシ子宮を卵巣所見及び頸管粘液の状態・インピーダンス値を指標として，発情期，黄体前期，黄体中期，黄体後期のステージに分け，子宮内膜小丘間組織を採取した。また，AI後，14日及び18日で子宮灌流により胚を確認できたウシの子宮内膜組織を採取した。採取した子宮内膜組織からmRNAを抽出し，オートファジー関連因子（ATG3，ATG5，ATG7，LC3α，LC3β，mTOR，Beclin1）及びリソソームカテプシン群（CTSB，CTSD，CTSL，CTSZ）の遺伝子発現定量解析を行った。【結果】発情周期のウシ子宮内膜小丘間組織におけるオートファジー関連因子の遺伝子発現に変動は見られなかったが，妊娠14日及び18日ではLC3αの有意な上昇が見られた。また，リソソームカテプシン群については，発情周期間での発現動態に差は見られなかったものの，妊娠14日及び18日でCTSZの有意な上昇が見られた。以上の結果よりウシ子宮におけるオートファジー-リソソームカテプシンは，妊娠特異的に変動し，着床に向けた子宮改編への関与が示唆された。
• 卵胞刺激ホルモンの尾椎硬膜外腔内単回投与が黒毛和種牛の体内・体外胚生産に及ぼす影響
  坂口 謙一郎; 出田 篤司; 土屋 加那美; 真方 文絵; 小牧 春菜; 佐藤 正明; 酒井 伸一; 馬塲 貴大; 柳川 洋二郎; 永野 昌志; 片桐 成二; 小西 正人
  北海道獣医師会雑誌, Aug. 2016, (公社)北海道獣医師会, Japanese
  Aug. 2016 - Aug. 2016
• 卵胞膜細胞と共培養した牛卵母細胞-顆粒膜細胞複合体の増殖、ステロイド産生とその後の発生能(Growth, steroidogenesis and subsequent developmental competence of bovine oocyte-granulosa cell complex co-cultured with theca cells)
  楊 応華; 菅野 智裕; 坂口 謙一郎; 柳川 洋二郎; 片桐 成二; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2016, (公社)日本獣医学会, English
  Aug. 2016 - Aug. 2016
• 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
  坂口 謙一郎; 谷田 孝志; 永井 克尚; 楊 応華; 柳川 洋二郎; 片桐 成二; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2016, (公社)日本獣医学会, Japanese
  Aug. 2016 - Aug. 2016
• 牛の小型卵母細胞の発生能に対する成熟前培養時間の影響(Effect of prematuration culture duration on developmental competences of bovine small sized oocytes)
  Mohammed.A. Abdle-Gahni; 坂口 謙一郎; 菅野 智裕; 楊 応華; 柳川 洋二郎; 片桐 成二; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2016, (公社)日本獣医学会, English
  Aug. 2016 - Aug. 2016
• 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
  菅野 智裕; 柳川 洋二郎; 片桐 成二; 高橋 芳幸; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2016, (公社)日本獣医学会, Japanese
  Aug. 2016 - Aug. 2016
• ペレット法による凍結保存が融解後のニホンザル精液の運動性に与える影響
  柳川 洋二郎; 菅野 智裕; 兼子 明久; 印藤 頼子; 岡本 宗裕; 片桐 成二; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2016, (公社)日本獣医学会, Japanese
  Aug. 2016 - Aug. 2016
• Effect on menstrual cycle of periodical ultrasonography in Japanese macaques (Macaca fuscata)
  INDO Yoriko; MINAMI Akiko; KANEKO Akihisa; SATO Yo; KINOSHITA Kodzue; YANAGAWA Yojiro; NAGANO Masashi; OKAMOTO Munehiro
  Primate Research Supplement, Jul. 2016, Primate Society of Japan, Japanese
  Jul. 2016 - Jul. 2016,

  我々は疾患モデルや貴重な遺伝子疾患個体を維持するため、ニホンザルの人工繁殖、特に人工授精技術の確立に取組んでいる。効率的に繁殖を制御するには、メスの排卵日を予測する卵巣動態の観察が不可欠である。アカゲザルでは、超音波診断装置（エコー）により卵巣動態の観察が報告されており、定期的な保定と飼育環境の変化という心因性ストレスは、性周期には影響しないことが報告されている。そこで我々は、ニホンザルにおいても定期的なエコーにより卵巣動態の観察が可能であると考えた。個別飼育下の4～9歳のメスザル3個体を11月～12月の1ヶ月間、週3回1日15分間保定し、エコーによる卵巣動態の観察を行った。また、8歳の1個体は麻酔下でエコーによる観察を同様の期間、週2回行った。実験期間中毎日採尿を行い、尿中のエストロゲンとプロジェステロンの代謝物（E1G、PdG）の量を測定するとともに、月経出血の有無を確認した。その結果、無麻酔エコーを行った3個体中2個体では月経出血が観察され、エコーにより卵胞の発育とその後の排卵が確認できた。しかし、残り1個体と麻酔下でエコーを実施した1個体では月経出血が認められず、卵胞の発育・排卵も確認できなかった。そこで、実験期間終了後、平常飼育下で4 個体の観察および採尿を続け、ホルモン動態とコルチゾール量を実験期間中と比較検討した。その結果、排卵した2個体では実験期間中と平常時でコルチゾール量に差はなかったが、卵胞の発育・月経出血の見られなかった2個体では平常時に比べ実験期間中で有意に高いことが示された。また、これら2個体のE1GとPdG値は実験期間中、排卵前に見られるE1Gの増加および排卵後に起こるPdGの増加が見られなかった。我々は、エコーは卵巣動態の観察に有用と考えたが、以上の結果からニホンザルでは個体によって頻回のエコー検査がストレスとなり、性周期に影響を及ぼすことが示唆された。

• Urinary sex steroid hormone concentrations of female Japanese macaque (Macaca fuscata) in indoor individual cage
  SATO Yo; INDO Yoriko; KINOSHITA Kodzue; YANAGAWA Yojiro; SOTOMARU Yusuke; OKAMOTO Munehiro
  Program and abstracts of PSJ, 2016, 日本霊長類学会, Japanese
  2016 - 2016, <p>ニホンザルは季節性多発情動物であり、秋から冬にかけての約6ヶ月間のみ発情し繁殖を行うことが知られている。発情期の間は卵巣機能が活性化して性ステロイドホルモンの分泌が促進され、またそれらのホルモン濃度は周期的な動きを示す。人工授精や胚移植など、人工繁殖技術を成功させるためには排卵のタイミングを正確に判定する必要がある。本研究では、室内個別飼育下の雌ニホンザルを対象に、非侵襲的に採取可能である尿サンプルを用いて、尿中発情ホルモン代謝産物（E1G）および黄体ホルモン代謝産物（PdG）濃度動態をみるために、酵素免疫測定法による測定を非繁殖期から繁殖期まで長期間実施し、室内個別飼育下の雌ニホンザル（N=16）における性周期の特徴と傾向を詳細に調べた。その結果、対象個体の半数は、一般的に知られているニホンザルの発情開始時期（9月）よりも2ヶ月ほど遅れて、11月後半より周期的なホルモン濃度動態を示し始めた。中には、1月に入ってからホルモン濃度の増加と周期的動態を示した個体もいた。また、E1GおよびPdG濃度のピークの値は個体によって差がみられた（E1G: 43.4-301.2 ng/ml，PdG: 262.3-3957.2 ng/ml）。さらに、繁殖期に生理出血がみられていても不規則であり、性ステロイドホルモン濃度動態にも周期性がみられない個体もいた。これらは、ホルモン濃度動態から排卵を伴わない生理出血であったことが内分泌学的に示唆された。よって、室内個別飼育下の個体を使用して、胚移植などの人工繁殖技術を実施する際は、レシピエントなどの対象個体の発情時期が通常より遅延すること、また、生理出血がみられていても卵巣機能が正常な周期性を保っていない可能性があることを考慮すべきであると示唆された。これらの傾向は、室内飼育下においては環境温度や光周期といった外部環境が人工的に制御されており、年間を通して変化が乏しいことによると考えられた。</p>
• 凍結前精液の一時保存方法および冷却方法が融解後のマカク属精子の性状に与える影響
  栁川洋二郎; 杉本幸介; 菅野智裕; 高江州昇; 印藤頼子; 兼子明久; 木下こづえ; 今井啓雄; 岡本宗裕; 片桐成二; 永野昌志
  Cryopreservation Conference 2014, Oct. 2015, Japanese
  Oct. 2015 - Oct. 2015
• CIITA遺伝子発現の抑制がウシ初期胚発生に与える影響
  秋沢宏紀; 長友啓明; 定郁里; 岸靖典; 山中賢一; 詫摩哲也; 佐々木恵亮; 山内伸彦; 柳川洋二郎; 永野昌志; 河野友宏; 高橋昌志; 川原学
  日本畜産学会大会講演要旨, 11 Sep. 2015, Japanese
  11 Sep. 2015 - 11 Sep. 2015
• 霊長類の生殖細胞エピゲノムの進化とゲノム進化の相互作用
  福田渓; 一柳健司; 佐々木裕之; 永野昌志; 柳川洋二郎; 高江洲昇; 高江洲昇; 今井啓雄
  日本遺伝学会大会プログラム・予稿集, 10 Sep. 2015, Japanese
• 牛の卵子品質と卵巣内卵胞数の関係 体内および体外発育卵子を用いた予備的検討
  永井 克尚; 杉山 ちさと; 楊 応華; 柳川 洋二郎; 片桐 成二; 永野 昌志
  The Journal of Reproduction and Development, Sep. 2015, 日本繁殖生物学会, Japanese
  Sep. 2015 - Sep. 2015
• ニホンザルにおける電気刺激時の電圧が精子採取に与える影響および精子凍結保存法の改善について
  杉本 幸介; 柳川 洋二郎; 菅野 智裕; 高江洲 昇; 兼子 明久; 印藤 頼子; 岡本 宗裕; 片桐 成二; 永野 昌志
  日本獣医学会学術集会講演要旨集, Aug. 2015, (公社)日本獣医学会, Japanese
  Aug. 2015 - Aug. 2015
• アンドロジェン受容体を発現するヒグマ(Ursus arctos)の背部脂腺は血中テストステロン濃度の高い交尾期に発達する
  冨安洵平; 松本直也; 坂元秀行; 柳川洋二郎; 永野昌志; 佐々木基樹; 松井基純
  日本野生動物医学会大会・講演要旨集, 01 Jul. 2015, Japanese
• C-4 ニホンザルの月経周期における卵巣動態の解明と人工授精技術の開発
  栁川 洋二郎; 永野 昌志; 姜 成植; 南 晶子; 正木 智之; 簑原 悠太朗; 髙江洲 昇; 伊藤 真輝; 菅原 里沙; 小林 真也
  霊長類研究所年報, 04 Dec. 2014, 京都大学霊長類研究所, Japanese
  04 Dec. 2014 - 04 Dec. 2014
• 北海道道南地域のエゾシカにおけるロタウイルスAおよびウシコロナウイルス遺伝子保有状況および抗体保有状況
  松山亮太; 岡寺康太; 柳川洋二郎; 三竹博道; 小林恒平; 中村大輔; 淺野玄; 伊藤直人; 秦寛; 近藤誠司; 恒光裕; 杉山誠; 鈴木正嗣
  野生生物と社会学会大会プログラム・講演要旨集, 31 Oct. 2014, Japanese
• ニホンザル凍結保存精子の体外受精能
  外丸祐介; 信清麻子; 畠山照彦; 吉岡みゆき; 神田暁史; 印藤頼子; 兼子明久; 永野昌志; 柳川洋二郎; 高江洲昇; 岡本宗裕
  Cryopreservation Conference 2014, Oct. 2014, Japanese
  Oct. 2014 - Oct. 2014
• 希少霊長類遺伝資源の保存方法の確立
  今井啓雄; 岡本宗裕; 印藤頼子; 外丸祐介; 信清麻子; 神田暁史; 伊佐正; 永野昌志; 柳川洋二郎; 高江洲昇; 北島龍之介; 今村公紀; 平井啓久
  Cryopreservation Conference 2014, Oct. 2014, Japanese
  Oct. 2014 - Oct. 2014
• 交尾期にみられる雄成獣エゾヒグマ背部皮膚腺の変化
  冨安洵平; 松本直也; 坂元秀行; 柳川洋二郎; 永野昌志; 小林恒平; 松井基純
  日本哺乳類学会大会プログラム・講演要旨集, 04 Sep. 2014, Japanese
• 霊長類の生殖細胞エピゲノムの進化
  福田渓; 一柳健司; 永野昌志; 柳川洋二郎; 高江洲昇; 今井啓雄; 佐々木裕之
  日本遺伝学会大会プログラム・予稿集, 31 Aug. 2014, Japanese
• ネコ目動物3種における尿道カテーテル挿入による精子採取
  高江洲昇; 伊藤真輝; 菅原里沙; 柳川洋二郎; 永野昌志; 佐鹿万里子; 下鶴倫人; 坪田敏男
  日本獣医学会学術集会講演要旨集, 11 Aug. 2014, (公社)日本獣医学会, Japanese
  11 Aug. 2014 - 11 Aug. 2014
• 精子運動能自動解析装置(CASA)を用いた牛精子生存性の評価に関する基礎的検討
  菅野智裕; 今田康博; 姜成植; 柳川洋二郎; 永野昌志
  日本獣医学会学術集会講演要旨集, 11 Aug. 2014, Japanese
  11 Aug. 2014 - 11 Aug. 2014
• ホルスタイン牛における分娩後のビートパルプ給与が繁殖成績に及ぼす影響
  正木智之; MIN Bow; 上田宏一郎; 柳川洋二郎; 永野昌志
  日本獣医学会学術集会講演要旨集, 11 Aug. 2014, Japanese
  11 Aug. 2014 - 11 Aug. 2014
• ウシ子宮内膜組織におけるMX1とMX1B発現に及ぼすI型インターフェロンの応答性およびその受容体の発情周期別比較
  白水貴大; 川原学; 木村康二; 高橋ひとみ; 柳川洋二郎; 永野昌志; 白汝嵐; 今川和彦; 高橋昌志
  J Reprod Dev, 10 Aug. 2014, Japanese
  10 Aug. 2014 - 10 Aug. 2014
• ニホンザルにおける体外培養系受精卵の作製
  外丸祐介; 信清麻子; 畠山照彦; 吉岡みゆき; 印藤頼子; 兼子明久; 高江洲昇; 柳川洋二郎; 永野昌志; 岡本宗裕
  日本実験動物学会総会講演要旨集, 01 May 2014, Japanese
• ニホンザル(Macaca fuscata)の周排卵期における卵巣およびホルモン動態
  南晶子; 柳川洋二郎; 印藤頼子; 兼子明久; 岡本宗裕; 永野昌志
  日本野生動物医学会大会・講演要旨集, 2014, Japanese
• ヒグマ(Ursus arctos)におけるカテーテル法を用いた精液採取:オキシトシン投与が精液採取と精子品質に与える影響
  柳川洋二郎; 簑原悠太朗; 冨安洵平; 松本直也; 坂元秀行; 松井基純; 永野昌志
  日本野生動物医学会大会・講演要旨集, 2014, Japanese
• カテーテル法を用いたホッキョクグマ(Ursus maritimus)の採精と造精機能向上への取り組み
  中村亮平; 佐藤伸高; 佐橋智弘; 坂東元; 柳川洋二郎; 松井基純; 楠田哲士; 永野昌志
  日本野生動物医学会大会・講演要旨集, 2014, Japanese
• C-5 ニホンザルの人工繁殖を目指した技術開発
  高江洲 昇; 小林 真也; 石橋 佑規; 伊藤 真輝; 永野 昌志; 柳川 洋二郎; 小林 すみよ; 木下 ひより; 今田 康博; 姜 成植
  霊長類研究所年報, 13 Nov. 2013, 京都大学霊長類研究所, Japanese
  13 Nov. 2013 - 13 Nov. 2013
• 誘引狙撃法のニホンジカに対するスレ防止効果の検証
  亀井 利活; 柳川 洋二郎; 中村 大輔; 小林 恒平; 近藤 誠司; 秦 寛; 鈴木 正嗣
  日本霊長類学会大会プログラム抄録集, 06 Sep. 2013, Japanese
   近年，同一地域におけるニホンジカの継続的な捕獲の困難化が課題となっている．その要因として，捕獲行為への警戒心が高いスレたシカの存在が示唆され，スレ防止を目的とした捕獲手法として誘引狙撃法が検討されている．しかし，この手法による直接的なシカの行動変化やその防止効果は明らかとなっていない．そこで本研究では，捕獲によるシカの行動変化を明らかにすると共に，捕獲手法の違いによる行動変化から誘引狙撃法のスレ防止効果を検証した．
   本研究ではまず，2011年8，11月に北海道大学静内研究牧場において成雌シカ 3頭（No.1～3）に GPS発信機を装着した．その後，誘引狙撃法を同牧場内において 2011年 11月，2012年3，6月に 3回実施し，巻狩りを同牧場に隣接した家畜改良センター内で 2012年 2月に１回実施した．測位データは個体別に各捕獲の実施期間，実施前後 2週間に分け，各期間におけるその行動圏を最外殻法（95%MCP）により算出した．
   誘引狙撃法は全個体の行動圏内で実施されていたが，巻狩りはNo.1， 3の行動圏外で実施されていた．全個体において 11月の誘引狙撃実施時および実施前後に行動の変化は認められなかった．しかし，2月の巻狩り時に勢子による追い出しを経験した No.2は，巻狩り直後に実施前の行動圏外への一時的な移動が認められた．その後，実施前の行動圏に戻ってきたものの，3月の誘引狙撃実施直後に 2月と同様な移動が認められた．しかし，6月の誘引狙撃実施時においては，そのような行動は観察されなかった．一方，No.1，3では巻狩りとその後の誘引狙撃実施時および実施前後において行動の変化等は認められなかった．
   以上より，巻狩りは誘引狙撃法に比べて行動を変化させるほど強い影響を有し，スレる要因となることが認められた．一方，誘引狙撃法では顕著な行動の変化は認められず，スレ防止効果を有することが示唆された．
• 牛初期胞状卵胞由来卵子の体外発育に及ぼすFSHと骨形成タンパク質4の影響
  坂口謙一郎; 柳川洋二郎; 姜成植; 黄偉平; 高橋芳幸; 永野昌志
  J Reprod Dev, 20 Aug. 2013, 日本繁殖生物学会, Japanese
  20 Aug. 2013 - 20 Aug. 2013, 【目的】牛卵子の体外発育培養 (IVG) 中の性ステロイドホルモン産生能と卵子核成熟能の関係を明らかにするため，卵子-卵丘細胞-顆粒層細胞複合体 (OCGC) をアンドロステンジオン (A) 添加培地で培養し，以下の実験を行った。【材料と方法】OCGCを4日間IVGし，形態が正常なOCGC (生存群) と顆粒層細胞が卵子から遊走あるいは卵細胞質が変性しているOCGC (死滅群) のエストロジェン(E)およびプロジェステロン (P) 産生を比較した。次に，生存群のIVG培地に0あるいは0.5 ng/ml FSHおよび0，10あるいは50 ng/ml骨形成タンパク質 (BMP) 4 を添加して6実験群を作製し，さらに8日間培養してE・P産生およびIVG後のOCGC生存率，卵子直径および核成熟能について検討した。【結果】IVG4日目に形態的に正常と判定されたOCGCでは死滅群に比べてE産生が高く，P産生は低かった。生存OCGCのE産生量は，全実験群においてIVG8日目まで増加し，12日目には低下したがP産生はIVG期間を通して増加した。BMP添加に拘らず，FSH添加はE産生を低下させ，P産生を増加させた。50-ng BMP添加によりE・P産生は共に低下したが，10-ng BMP添加ではE産生は低下せず，P産生のみ低下させた。IVG12日後のOCGC生存率はFSH添加によって高くなり，FSH無添加+50-ng BMP添加で低くなった。卵母細胞の直径はFSH添加+50-ng BMP添加の場合に最小となった。IVG卵子の核成熟率はFSH無添加+10-ng BMP添加で低くなったが，他群では70–80%で同等であった。【考察】牛OCGCのIVGでは，生存OCGCは発育中の卵胞に近いEおよびP産生能を示すがIVG期間延長と共に退行卵胞様のE/P比低下が認められた。しかし，培地にFSHと共にBMP-4を10 ng/ml添加することで，OCGCの生存性を高めると共にE/P比を高く維持することが示された。
• Multi-well plate (MWP)とWell of the well (WOW)が牛卵子の体外成熟，受精，発生に及ぼす影響
  姜 成植; 今井 敬; 大藤 壮輔; 黄 偉平; 古山 敬祐; 柳川 洋二郎; 高橋 芳幸; 永野 昌志
  日本繁殖生物学会 講演要旨集, 2013, 日本繁殖生物学会, Japanese
  2013 - 2013, To develop individual culture system for bovine oocytes, effect of individual maturation in MWP and individual culture in WOW were examined. For investigating influence of MWP on IVM, IVF and IVC (Exp. 1), oocytes were matured individually in MWP or 10-µl droplet and in 50-µl droplet in a group as control. Nuclear maturation, fertilization and development were evaluated in all experimental groups. Maturation rates were similar in all experimental groups. After fertilization, oocytes from 10-µl droplet IVM showed significantly higher rate of enlarged sperm head compared with those of other groups even though fertilization rates of all groups were similar. Blastocyst rates of oocytes matured in MWP and in 50-µl droplets tended to be higher than that in 10-µl droplets. For investigating influence of WOW on IVC (Exp. 2), fertilized oocytes were cultured in WOW. Cleavage and blastocyst development were assessed, and effect of number of neighbor embryos (0, 3, 5 and 8) in a WOW on embryonic development was also examined. As control, 5 or 25 embryos were cultured in a 40-µl droplet. No differences of blastocyst rate were observed in all experimental groups. However, cell numbers in blastocysts of 5 embryos in droplets were significantly low. Number of adjacent embryos in a WOW dish did not affect blastocyst development and cell numbers of blastocysts. In conclusion, MWP supports the acquisition of developmental competence of individual bovine oocytes as same as conventional group maturation system. Further, WOW can provide high and stable blastocyst development in small embryo group wherever embryos are placed in micro-wells of WOW.
• エゾシカの発達および性成熟過程における卵胞形成と卵胞でのステロイド合成能
  小林すみよ; 柳川洋二郎; 坪田敏男; 永野昌志
  日本野生動物医学会大会・講演要旨集, 2013, Japanese
• 尿道カテーテル法を応用したニホンザルの精液採取
  高江洲昇; 柳川洋二郎; 永野昌志; 兼子明久; 今井啓雄; 岡本宗裕; 下鶴倫人; 坪田敏男
  日本野生動物医学会大会・講演要旨集, 2013, Japanese
• 牛ウイルス性下痢ウイルス1型に対するワクチンの有効性について
  大和田真紀; 川内京子; 鈴木浩幸; 柳川洋二郎
  日本獣医師会獣医学術学会年次大会講演要旨集, 20 Jan. 2012, Japanese
• サラブレッドにおける分娩後初回発情交配の生産率への影響:日本における過去12年間の繁殖成績の解析
  山崎洋祐; 原裕幸; 南保泰雄; 遠藤祥郎; 村瀬晴崇; 高橋芳幸; 永野昌志; 柳川洋二郎; 佐藤文夫
  日本獣医学会学術集会講演要旨集, 31 Aug. 2011, Japanese
  31 Aug. 2011 - 31 Aug. 2011
• 野生エゾシカにおけるin vitro消化特性の季節変化
  八代田千鶴; 西谷一哉; 上田宏一郎; 柳川洋二郎; 松浦友紀子; 早川大輔; 鈴木正嗣; 秦寛; 近藤誠司
  日本畜産学会大会講演要旨, 27 Mar. 2007, Japanese
• 野生エゾシカ消化管内の縮合タンニン含量の季節毎の比較
  西谷一哉; 八代田千鶴; 上田宏一郎; 柳川洋二郎; 松浦友紀子; 鈴木正嗣; 秦寛; 近藤誠司
  日本畜産学会大会講演要旨, 27 Mar. 2007, Japanese
• 秋季および冬季における野生エゾシカの消化管内タンニン含量の比較
  西谷一哉; 八代田千鶴; 上田宏一郎; 柳川洋二郎; 松浦友紀子; 鈴木正嗣; 秦寛; 近藤誠司
  北海道畜産学会大会講演要旨, 28 Aug. 2006, Japanese

• 産業動物獣医療実習, 2024年, 学士課程, 獣医学部
• Human-Animal Bond and One Health 特別科目群, 2024年, 博士後期課程, 獣医学院
• プレクリニカル実習, 2024年, 学士課程, 獣医学部
• Human-Animal Bond and One Health 特別科目群, 2024年, 博士後期課程, 国際感染症学院
• 産業動物獣医療実習Ⅰ, 2024年, 学士課程, 獣医学部
• 臨床疾病学特論, 2024年, 博士後期課程, 獣医学院
• 産業動物獣医療実習Ⅱ, 2024年, 学士課程, 獣医学部
• 動物生殖医学特論, 2024年, 博士後期課程, 獣医学院
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• 総合専門臨床特論, 2024年, 博士後期課程, 獣医学院
• 産業動物獣医療実習Ⅰ, 2024年, 学士課程, 獣医学部
• 産業動物獣医療実習Ⅱ, 2024年, 学士課程, 獣医学部
• 繁殖生理学, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• 生産獣医療学演習, 2024年, 学士課程, 獣医学部
• 動物衛生学実習, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• 専門横断科目（一般科目）：自然科学・応用科学, 2024年, 学士課程, 専門横断科目
• 専門横断科目（一般科目）：自然科学・応用科学, 2024年, 学士課程, 専門横断科目
• 動物園学, 2024年, 学士課程, 獣医学部
• プレクリニカル実習, 2024年, 学士課程, 獣医学部
• 基礎動物栄養学, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部
• アドバンスト演習, 2024年, 学士課程, 獣医学部

• 2015 - Present
  日本繁殖生物学会
• 2014 - Present
  International Embryo Transfer Society
• 2012 - Present
  JAPANESE SOCIETY OF VETERINARY SCIENCE
• 2011 - Present
  北海道牛受精卵移植研究会
• 2009 - Present
  JAPAN VETERINARY MEDICAL ASSOCIATION
• 2006 - Present
  THE MAMMALOGICAL SOCIETY OF JAPAN
• 2003 - Present
  JAPANESE SOCIETY OF ZOO AND WILDLIFE MEDICHINE

• 哺乳類の着床遅延状態評価にむけた末梢血の変動遺伝子特定と着床関連タンパク質の同定
  科学研究費助成事業
  01 Apr. 2025 - 31 Mar. 2028
  柳川 洋二郎
  日本学術振興会, 基盤研究(C), 北海道大学, 25K09451
• 乳牛の分娩間隔短縮技術改良・実証事業
  令和6年度 日本中央競馬会畜産振興事業
  Apr. 2024 - Mar. 2027
  日本中央競馬会, 北海道大学, Principal investigator
• 絶滅危惧種ツシマヤマネコの生息域外保全のための繁殖技術の確立と野生復帰環境の解明
  科学研究費助成事業
  Apr. 2024 - Mar. 2027
  楠田 哲士; 柳川 洋二郎; 堀 達也; 木下 こづえ
  日本学術振興会, 基盤研究(B), 岐阜大学, 24K01780
• 雌ニホンザルにおける性腺刺激ホルモン放出ホルモン徐放剤による繁殖抑制効果の持続性および可逆性の検証
  令和7年度 京都大学ヒト行動進化研究センター共同利用・共同研究
  Apr. 2025 - Mar. 2026
  京都大学ヒト行動進化研究センター, 一般研究, 北海道大学, Principal investigator, 2025-020
• 霊長類におけるホルモン剤を用いた可逆的な避妊方法
  令和5年度 京都大学ヒト行動進化研究センター共同利用・共同研究
  Sep. 2023 - Mar. 2024
  京都大学ヒト行動進化研究センター, 一般研究, 北海道大学, Principal investigator, 2023-023
• 乳牛の分娩間隔短縮技術実用化・検証事業
  令和4年度 日本中央競馬会畜産振興事業
  Apr. 2022 - Mar. 2024
  北海道大学, Principal investigator
• Development of artificial insemination protocol in bear species: Theriogenological support in zoo animals.
  Grants-in-Aid for Scientific Research
  01 Apr. 2019 - 31 Mar. 2022
  Yanagawa Yojiro
  To enhance captive breeding in polar bears and brown bears, we established spermatogenesis index in males and elucidated follicular development pattern and estrus type in females. Also we determined tools and methods after detail examination of female reproductive organs, and developed ovulation induction method. Further, genetic examination in peripheral blood was suggested as marker for pregnancy during delayed implantation. In addition, I spread and shared theriogenological approach for zoo animal during collaboration with several zoo.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Hokkaido University, 19K06415
• ニホンザルにおける凍結精液を用いた人工授精プログラム開発
  霊長類研究所共同利用・共同研究
  Apr. 2020 - Mar. 2022
  一般研究, Principal investigator
• 乳牛の分娩間隔短縮のための技術開発事業
  日本中央競馬会畜産振興事業
  Apr. 2019 - Mar. 2022
  Principal investigator
• ニホンザルを中心としたマカク属の凍結精液性状の向上
  自然科学研究機構基礎生物学研究所共同利用研究
  Apr. 2020 - Mar. 2021
  生物遺伝資源新規保存技術開発共同利用研究, Principal investigator
• マカク属における精液凍結保存方法の改善と人工授精技術開発
  霊長類研究所共同利用・共同研究
  Apr. 2018 - Mar. 2020
  一般研究, Principal investigator
• 牛における卵管上皮細胞を用いた新規精子受精能獲得能評価法の開発および性選別精子の受精能獲得能機能評価（Ⅱ）
  公益財団法人伊藤記念財団助成
  Jul. 2018 - Mar. 2019
• アフリカゾウ精液の輸送および凍結保存法の検討
  京都大学野生動物研究センター 共同利用・共同研究
  Apr. 2018 - Mar. 2019
  計画研究－動物園・水族館, Principal investigator
• 牛における卵管上皮細胞を用いた新規精子受精能獲得能評価法の開発および性選別精子の受精能獲得能機能評価
  公益財団法人伊藤記念財団助成
  Jul. 2017 - Mar. 2018
  Principal investigator
• マカク属における精液凍結保存方法の改善と人工授精技術開発
  霊長類研究所共同利用・共同研究
  Apr. 2017 - Mar. 2018
  一般個人研究, Principal investigator
• レッサーパンダにおける繁殖促進および人工繁殖のための基礎調査
  野生動物保護募金助成
  Apr. 2017 - Mar. 2018
  動物園水族館協会, Principal investigator
• 牛性選別精液の受胎率向上を目指した新規精子受精能評価法の開発
  若手研究人材育成事業
  Aug. 2016 - Mar. 2017
  ノーステック財団, ノースタレント補助金, Principal investigator
• マカク属における凍結融解精液性状の改善と人工授精技術開発
  霊長類研究所共同利用・共同研究
  Apr. 2016 - Mar. 2017
  京都大学霊長類研究所, 一般個人研究, Principal investigator
• マカク属の月経周期における卵巣動態の解明と人工授精技術の開発
  霊長類研究所共同利用・共同研究
  Apr. 2015 - Mar. 2016
  京都大学霊長類研究所, 一般個人研究, Principal investigator
• ニホンザルの月経周期における卵巣動態の解明と人工授精技術の開発
  霊長類研究所共同利用・共同研究
  Apr. 2013 - Mar. 2015
  京都大学霊長類研究所, 一般グループ研究, Principal investigator
• ニホンジカ高密度個体群における繁殖特性の至近要因となる生理学的特徴の解明
  稲盛財団研究助成
  Apr. 2013 - Mar. 2014
  稲盛財団, Principal investigator