Mehcanisms for acentrosomal spindle bipolarization in mammalian oocytes

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K06682
• 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: Institute of Physical and Chemical Research
• Principal Investigator: Yoshida Shuhei 国立研究開発法人理化学研究所, 生命機能科学研究センター, 上級研究員 (20363997)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 染色体分配 / 卵母細胞 / 動原体

Outline of Final Research Achievements

Spindle bipolarization is prerequisite for chromosome segregation. However, mammalian oocytes do not have centrosomes which determine polarity of the spindle. Mechanisms for acentrosomal spindle bipolarization in mammalian oocytes have not been cleared yet.
We found that kinetochores are required for spindle bipolarization during meiosis I in mouse oocytes. We also found that spindle is bipolarized by different mechanisms between meiosis I and meiosis II in mouse oocytes. Artificially induced meiosis II-like spindle bipolarization during meiosis I increased chromosome missegregation, indicating kinetochore-based spindle bipolarization is required for faithful chromosome segregation during meiosis I in mouse oocytes.

Free Research Field

分子生物学

Academic Significance and Societal Importance of the Research Achievements

哺乳動物の卵母細胞における減数分裂では染色体分配異常が起こりやすく、流産や先天性疾患の原因となる。しかし哺乳動物の卵母細胞における染色体分配に重要な紡錘体の二極性化機構は未だ明らかになっていない。
我々は本研究において、マウス卵母細胞の減数第一分裂では動原体の機能が紡錘体の二極性化に必須であることを見出した。マウス卵母細胞における紡錘体の二極性化機構を明らかにすることは、哺乳動物の卵母細胞において染色体分配異常が起こりやすい原因解明の手掛かりとなることが期待される。