The evolutionary genetic basis of diversified sexual dimorphism in Adrianichthyidae fishes

2019 Fiscal Year Final Research Report

• Project/Area Number: 18K14769
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 45020:Evolutionary biology-related
• Research Institution: Tohoku University (2019); National Institute for Basic Biology (2018)
• Principal Investigator: ANSAI SATOSHI 東北大学, 生命科学研究科, 助教 (20779467)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Keywords: メダカ / 性的二型 / 婚姻色 / 性選択 / 配偶者選択 / ゲノム編集 / アンドロゲン

Outline of Final Research Achievements

To elucidate the evolutionary and genetic mechanisms underlying diversification in sexual dimorphism, we studied on the male nuptial coloration (red pectoral fins) of a medaka fish, Oryzias woworae, endemic to Sulawesi, Indonesia. A candidate gene on an autosome, identified by QTL analysis and RNA-seq, was disrupted by CRISPR/Cas system, and the mutant exhibited loss of red pigment cells. Then, androgen administration showed that the differential expression of the gene between two sexes is caused by androgen signaling. Furthermore, a mating experiment and a predator experiment using the knockout fish indicated that loss of the red coloration decreased the female mate preference but increased the preference by the predator.

Free Research Field

進化遺伝学

Academic Significance and Societal Importance of the Research Achievements

本研究では、婚姻色の原因遺伝子を同定し、ゲノム編集技術を適用することで、その適応的な意義を実験的に実証することに成功した。性選択を介した性的二型の多様化は、進化生物学における最も重要な問題の１つとして、数多くの理論や学説が形成されてきた。本研究は、今後これらの理論・学説を検証し、生物の多様化機構を理解していく上で、ゲノム編集技術を用いた原因遺伝子の機能解析が重要なアプローチの１つであることを示す上で重要な成果である。