哺乳類の卵におけるカルシウム振動は,溶解性精子タンパク質によって引き起こされる

J Parrington¹, K Swann, V I Shevchenko

¹MRC National Institute for Medical Research, The Ridgeway, London, UK.

Nature

|January 25, 1996

まとめ

研究者は精子タンパク質であるオシリンを特定し,哺乳類の卵の活性化と胚の発達に不可欠なカルシウム振動を誘発した. この発見は,受精と発達を開始する重要な要因を明らかにしています.

科学分野:

生殖生物学生殖生物学
発達生物学発達生物学とは
セルラー・シグナリング

背景:

精子によって引き起こされる卵中のカルシウム (Ca2+) 振動は,哺乳類の受精と胚の発達に不可欠です.
精子がこれらのCa2+振動を開始する正確なメカニズムはまだ不明です.
精子と卵の相互作用と細胞内Ca2+の放出との直接的な関連は確立されていません.

研究の目的:

哺乳類の卵におけるCa2+の振動を誘発する精子由来因子を特定する.
精子によって誘発される卵子活性化の基礎となる分子メカニズムを解明する.

主な方法:

Ca2+の振動を観察するために,精子エキスを哺乳類の卵に微量注入する.
Ca2+振動誘発活性を持つ精子タンパク質の生化学的特徴.
特定された精子タンパク質のクローニングと配列分析.

主要な成果:

オシリンと呼ばれる溶解性精子タンパク質は,卵子における強力なCa2+振動誘発 ('オシロゲン') 活動を持つと特定されました.
オシリンは,33Kサブユニットを持つオリゴーマーとして存在し,精子の赤道部分に局限しています.
33Kオシリンサブユニットの補完DNAは,プロカリオットヘクソスリンリン酸イソメラーゼと類似性を示しています.

結論:

オシリンは,哺乳類の卵子活性化に必要なCa2+振動を誘発する,精子由来の重要な因子として特定されています.
このタンパク質は,哺乳類の胚発達の生理学的トリガーを表している可能性が高い.
この発見は,受精の開始と早期の発達を理解するための分子基盤を提供します.

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