Study on improving the commodity value of farmed fish by analyzing the regulatory mechanism of sexual dimorphism in body size in fish

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K22587
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0603:Forestry and forest products science, applied aquatic science, and related fields
• Research Institution: Tohoku University (2022); The University of Tokyo (2020-2021)
• Principal Investigator: Kayo Daichi 東北大学, 生命科学研究科, 特任研究員 (40880373)
• Project Period (FY): 2020-09-11 – 2023-03-31
• Keywords: 魚類生殖生理

Outline of Final Research Achievements

The body size and fat content are directly linked to their commodity value in farmed fish. This study aimed to elucidate the physiological mechanisms that control these traits by focusing on the fact that sexual dimorphism in body growth is observed among various fish species. Using a gene knockout medaka model with the disappearance of the female-biased growth pattern due to the cyp19a1b gene knockout, we performed physiological analyses to understand the detailed phenotype and the underlying mechanisms. Additionally, we also discovered that allogeneic testes transplanted into partially castrated adult medaka can produce donor derived offspring through natural mating. This method may be helpful for establishing a simplified technique for surrogate father production.

Free Research Field

魚類生殖生理

Academic Significance and Societal Importance of the Research Achievements

本研究により、体サイズが通常より大きくなりかつ脂の乗りが優れた個体の生理状態、肝臓及び筋肉におけるメタボロームや代謝関連遺伝子の動態が網羅的に明らかになった。加えて、エストロゲンによる脂質合成の抑制作用を抑えることが上述の優れた形質をもつ養殖魚を作製する上で重要である可能性が示唆された。また、本研究により開発された簡易的な代理父親作製技術は、他個体の精巣を受け入れる免疫寛容の分子メカニズムを解明する糸口となり得る。これは優れた形質をもつ系統の選抜育種へ応用可能性を示唆するものである。