A study of mechanisms of monospermy by electrical block to polyspermy

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K06690
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 44020:Developmental biology-related
• Research Institution: Yamaguchi University
• Principal Investigator: Iwao Yasuhiro 山口大学, その他部局等, 名誉教授 (10144916)
• Co-Investigator(Kenkyū-buntansha): 上野 秀一 山口大学, 大学院創成科学研究科, 准教授 (80363092)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: 多精拒否

Outline of Final Research Achievements

Fertilization is essential for sexual reproduction in all animals. The eggs of most vertebrates accept only one sperm to eliminate the extra sperm outside the egg. The egg has a mechanism that prevents polyspermy at the time of fertilization, ensuring monospermic development. In this study, we elucidated the molecular mechanism of monospermic fertilization controlled by positive fertilization potential using amphibians, which are easy to experiment in fertilization. When the first sperm fertilizes and enters the egg, the egg’s membrane potential becomes positive (fertilization potential). A positive fertilization potential prevents membrane fusion with the subsequent sperm, preventing entry of multiple sperm into the fertilized egg. We have proved with matrix metalloproteinase-2 (MMP-2) deficient sperm that positively charged MMP-2 is distributed on the sperm membrane and is essential for the polyspermy block as a sensor for detecting the positive fertilization potential.

Free Research Field

発生生物学

Academic Significance and Societal Importance of the Research Achievements

受精はすべての動物の有性生殖に必須であり、次世代個体の維持とともに進化における種分化に重要な役割をもっている。今回の研究では、脊椎動物での受精機構のモデルである両生類を用いて早い電気的多精拒否の分子メカニズムを明らかにした。これは動物界全般に共通な受精における普遍的な機能分子の解明に繋がると考えられる。さらに今後、ヒトを含む哺乳類における受精機構の解明や不妊治療の開発等での基盤研究に貢献することが期待される。