(1) ナイルティラピア、ニホンウナギ、チョウザメ類の性分化機構の解明

(2) 魚類卵成熟誘起ステロイド産生機構に関する研究

(3) ニホンウナギ人為催熟に関する研究

(4) 魚類ステロイドホルモン産生制御機構に関する分子生物学的研究

Shigeho Ijiri, Yasushi Shibata, Nonoha Takezawa, Yukinori Kazeto, Naoki Takatsuka, Erika Kato, Seishi Hagihara, Yuichi Ozaki, Shinji Adachi, Kohei Yamauchi, and Yoshitaka Nagahama. 17β-HSD type 12-like is responsible for maturation-inducing hormone synthesis during oocyte maturation in masu salmon. Endocrinology 158: 627-639. (2017)



Hatsumi Okada, Seishi Hagihara, Satoshi Yamada, Katsumasa Yamashita, Shigeho Ijiri*, Shinji Adachi. Expression pattern of foxl2 and dmrt1 in gonad of Amur sturgeon Acipenser schrenckii in relation to sex differentiation. Aquaculture 479:712–720 (2017)



Izumi H, Gen K, Horiuchi M, Matsuya N, Ijiri S, Adachi S. Quantitative comparisons of maternal transcripts related to cell division between good and poor quality eggs from artificially matured Japanese eel Anguilla japonica. Aquaculture Science 64(1), 29-42. (2016)



Kaneko H, Ijiri S, Kobayashi T, Izumi H, Kuramochi Y, Wang DS, Mizuno S, Nagahama Y. Gonadal soma-derived factor (gsdf), a TGF-beta superfamily gene, induces testis differentiation in the teleost fish Oreochromis niloticus. Molecular and Cellular Endocrinology 415, 87-99. (2015)



Ting Su, Shigeho Ijiri*, Hirokazu Kanbara, Seishi Hagihara, De-Shou Wang, Shinji Adachi. Characterization and expression of cDNAs encoding P450c17-II (cyp17a2) in Japanese eel during induced ovarian development. General and Comparative Endocrinology 221, 134-143. (2015)



S. Hagihara, R. Yamashita, S. Yamamoto, M. Ishihara, T. Abe, S. Ijiri* and S. Adachi. Identification of genes involved in gonadal sex differentiation and the dimorphic expression pattern in undifferentiated gonads of Russian sturgeon Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833 Journal of Applied Ichthyology 30, 1557-1564. (2014)



Yan H, Ijiri S, Wu Q, Kobayashi T, Li S, Nakaseko T, Adachi S, Nagahama Y. Expression patterns of gonadotropin hormones and their receptors during early sexual differentiation in Nile tilapia, Oreochromis niloticus. Biology of Reproduction, 87(5):116, 1-11. (2012)



Tsukamoto K, Chow S, Otake T, Kurogi H, Mochioka N, Miller M.J., Aoyama J, Kimura S, Watanabe S, Yoshinaga T, Shinoda A, Kuroki M, Oya M, Watanabe T, Hata K, Ijiri S, Kazeto Y, Nomura K, Tanaka H. Oceanic spawning ecology of freshwater eels in the western North Pacific. Nature Communications, 2, 179. (2011)



Ijiri S, Tsukamoto K, Chow S, Kurogi H, Adachi S, Tanaka H. Controlled reproduction in the Japanese eel (Anguilla japonica), past and present. Aquaculture Europe, 36, 13-17. (2011) (招待論文）



Abe T, Ijiri S, Adachi S, Yamauchi K. Development of an in vitro culture system for producing eel larvae from immature ovarian follicles in Japanese eel Anguilla japonica. Fisheries Science, 76, 257-265. (2010) （日本水産学会論文賞）



Ijiri S, Kaneko H, Kobayashi T, Wang DS, Sakai F, Paul-Prasanth B, Nakamura M, Nagahama Y. Sexual dimorphic expression of genes in gonads during early differentiation of a teleost fish, the Nile tilapia Oreochromis niloticus. Biology of Reproduction, 78, 333-341. (2008) (2007-2008年の引用数最高論文の1つとして感謝状授与）



Ijiri S, Takei N, Kazeto Y, Todo T, Adachi S, Yamauchi K. Changes in localization of cytochrome P450 cholesterole side-chain cleavage (P450scc) in Japanese eel testis and ovary during gonadal development. General and Comparative Endocrinology 145, 75-83. (2006) 



Wong TT, Ijiri S, Zohar Y. Molecular biology of ovarian aromatase in sex reversal: Complementary DNA and 5 '-flanking region isolation and differential expression of ovarian aromatase in the Gilthead Seabream (Sparus aurata). Biology of Reproduction, 74,857-864. (2006)



Kazeto Y, Ijiri S, Adachi S, Yamauchi K. Cloning and characterization of a cDNA encoding cholesterol side-chain cleavage cytochrome P450 (CYP11A1): Tissue-distribution and changes in the transcript abundance in ovarian tissue of Japanese eel, Anguilla japonica, during artificially induced sexual development. Journal of Steroid Biochemistry and Molecular Biology 99, 121-128. (2006)



Ijiri S, Kazeto Y, Lokman PM, Adachi S, Yamauchi K. Characterization of a cDNA encoding P-450 aromatase (CYP19) from Japanese eel ovary and its expression in ovarian follicles during induced ovarian development. General and Comparative Endocrinology 130, 193-203. (2003)



Steven C, Lehnen N, Kight K, Ijiri S, KlenkeU, Harris WA, Zohar Y. Molecular characterization of the GnRH system in zebrafish (Danio rerio): cloning of chicken GnRH-II, adult brain expression patterns and pituitary content of salmon GnRH and chicken GnRH-II. General and Comparative Endocrinology 113, 27-37. (2003)



Kumar RS, Ijiri S, Trant JM. Molecular Biology of Channel Catfish Gonadotropin Receptors: 1. Cloning of a Functional Luteinizing Hormone Receptor and Preovulatory Induction of Gene Expression. Biology of Reproduction 64, 1010-1018. (2001)



Ijiri S, Berard C, Trant JM. Characterization of gonadal and extra-gonadal forms of the cDNA encoding the Atlantic stingray (Dasyatis sabina) cytochrome P450 aromatase (CYP19). Molecular and Cellular Endocrinology 164, 169-181. (2000)



Ijiri S, Kayaba T, Takeda N, Tachiki H, Adachi S, Yamauchi K. Pretreatment reproductive stage and oocyte development induced by salmon pituitary homogenate in the Japanese eel Anguilla japonica.  Fisheries Science 64, 531-537. (1998)



Ijiri S, Kazeto Y, Takeda N, Chiba H, Adachi S, Yamauchi K. Changes in serum steroid hormones and steroidogenic ability of ovarian follicles during artificial maturation of cultivated Japanese eel, Anguilla japonica. Aquaculture 135, 3-16. (1995)

学部

細胞分子生物学

水圏生物学実験



大学院

増殖生物学特論Ⅰ（分担）

増殖生物学特論Ⅱ（分担）

生物生産技術特論（分担、食資源学院）

1992年　北海道大学水産学部　卒業

1997年　北海道大学・大学院水産科学研究科　学位取得

1997年　米国・メリーランド大学・バイオテクノロジー研究所・博士研究員

2001年　北海道大学水産学部　学振PD特別研究員

2004年　自然科学研究機構・基礎生物学研究所・博士研究員

2006年　北海道大学水産科学研究院　助教授

2007年　北海道大学水産科学研究院　准教授

魚類の生殖細胞発達のメカニズムを解明し、性分化と性成熟をコントロールする技術開発の実現を目指し、以下の3つのテーマに取り組んでいます。１）ティラピア：性分化メカニズムを解明する。YY雄（超雄）とYY雌（超雄偽雌）個体作製を容易にする。２）チョウザメ：遺伝子発現の性分化を明らかにする。全雌作製法を開発する。性成熟期への移行メカニズムの解明。３）ウナギ：マリアナ海域天然成熟ウナギの卵を分子的に解明する。性成熟移行に関わる分子を同定する。４）全ての魚種を通して卵成熟誘起ホルモン産生機構を解明する。