Molecular mechanisms that make differences between mitosis and meiosis

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03634
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Molecular biology
• Research Institution: Kumamoto University
• Principal Investigator: Ishiguro Keiichiro 熊本大学, 発生医学研究所, 准教授 (30508114)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 減数分裂 / 生殖細胞 / 精子 / 卵子

Outline of Final Research Achievements

The mechanisms regulating meiotic initiation in mammals are enigmatic. It is known that retinoic acid (RA) signaling plays a pivotal role during meiotic initiation. STRA8, which is expressed in response to RA, is thought to be a key factor promoting meiotic initiation. Here we identified MEIOSIN as a germ cell-specific factor that associates with STRA8. MEIOSIN, like STRA8, is expressed in response to RA and plays an essential role in meiotic initiation in both males and females. Functional analyses revealed that MEIOSIN acts as a transcription factor together with STRA8, and that both factors are critical for driving meiotic gene activation. Furthermore, temporally restricted expression of MEIOSIN leads to meiotic entry decision during spermatogenesis. The present study demonstrates that MEIOSIN, in collaboration with STRA8, plays a central role in regulating the mitosis to meiosis germ cell fate decision in mammals.

Free Research Field

発生生物学

Academic Significance and Societal Importance of the Research Achievements

今回新たに発見したMEIOSINが、卵巣・精巣内で特殊な細胞分裂である減数分裂を開始させる働きをもつことを明らかにしました。また、MEIOSINは卵子・精子を形成するための数百種類の遺伝子に一斉にスイッチを入れる司令塔の役割を果たしていることを明らかにしました。MEIOSINは、減数分裂の発動に必須の働きをしており、卵子や精子の形成に関わる重要な遺伝子であることから、今後の不妊治療などの生殖医療の進展につながる可能性があります。