Underlying mechanism of germline sex determination by FOXL3 and its co-factors

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K23749
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0702:Biology at cellular to organismal levels, and related fields
• Research Institution: Nagoya University
• Principal Investigator: Kikuchi Mariko 名古屋大学, 理学研究科, 助教 (20845135)
• Project Period (FY): 2019-08-30 – 2021-03-31
• Keywords: 生殖細胞 / 性決定 / 卵形成 / メダカ

Outline of Final Research Achievements

Using CRISPR/Cas9 system, I generated medaka mutant lines of fbxo47 and rec8a, direct targets of FOXL3. fbxo47-mutant females were sterile, while males were fertile. The mutant ovaries lacked follicles, and chromosome in germ cells exhibited ring-like morphology possibly caused by telomere fusion. Furthermore, the fbxo47-mutant germ cells committed into spermatogenesis, suggesting that FBXO47 has a role in suppression of spermatogenesis. rec8a-mutant females were also sterile, and progression of meiosis was severely defected in germ cells. These results firstly revealed the molecular pathways that initiates several events in female germ cells (e.g. folliculogenesis, suppression of spermatogenesis, and meiosis progression).

Free Research Field

生殖生物学

Academic Significance and Societal Importance of the Research Achievements

REC8AとFBXO47はそれぞれ染色体の高次構造とタンパク質分解に関わる因子であり、これらの事象と生殖細胞の性決定との関連が本研究で初めて示された。今後REC8AとFBXO47の機能を詳細に調べることで、生殖細胞の性を決める仕組みと卵を作り出す仕組みが分子レベルでより詳細に明らかになると考えられる。
そして卵や精子への経路を決める仕組みが明らかになれば、畜産・水産業において家畜や養殖魚の繁殖効率上昇や、生殖医療技術の改善につながると期待される。