Elucidation of the interplay between genetic and environment-dependent mechanisms of sex determination in atheriniform fishes, a group in which these two mechanisms functionally coexist

2023 Fiscal Year Final Research Report

• Project/Area Number: 19H03048
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 40040:Aquatic life science-related
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: Yamamoto Yoji 東京海洋大学, 学術研究院, 准教授 (10447592)
• Co-Investigator(Kenkyū-buntansha): Strussmann C.A. 東京海洋大学, 学術研究院, 教授 (10231052)
• Project Period (FY): 2019-04-01 – 2024-03-31
• Keywords: 環境依存型性決定機構 / 遺伝型性決定機構 / 環境ストレス / トウゴロウイワシ / TSD

Outline of Final Research Achievements

This project aims to elucidate the interplay between genetic and temperature-dependent mechanisms of sex determination in atheriniform fishes, a group in which these two mechanisms functionally coexist. Functional disruption of amhy, a male sex-determining factor on the Y chromosome, using CRISPER-Cas9 technology in genetic males (XY) resulted in increased expression of cyp19a1a, a key factor for female sex differentiation, and some individuals developed into females. The results of reporter gene assays of key sex determination/differentiation genes suggest that gene expression of amhy, amha and cyp19a1a are regulated by cortisol and 11-KT, which are associated with stress-related masculinization during temperature-dependent sex determination. Our results provide new insights on how genetic sex determinants, key genes for male and female sex differentiation, and various stress- and sex-related hormones interplay in a delicate balance to induce the formation of each sex.

Free Research Field

魚類繁殖生理学

Academic Significance and Societal Importance of the Research Achievements

本課題では、これまで未解明であった、魚類の性決定・性分化過程における「遺伝的要因」と「環境要因」の共在機構の解明に迫った。本成果は、気候変動や地球温暖化、海洋酸性化など人為的環境ストレスによる水圏環境の急激な変化が地球規模での問題となっている昨今において、生物の繁殖の根幹をなす性決定への「環境要因」の作用機序解明にも繋がり、雌雄異体魚における性決定機構の解明のみならず、恒久的な魚類資源の利用と生物多様性の保全に寄与すると期待される。