Mechanism of initiation of development via an increase of intracellular pH

通过增加细胞内 pH 值启动发育的机制

• 批准号: 13680801
• 负责人: CHIBA Kazuyoshi
• 金额: $ 2.37万
• 依托单位: Ochanomizu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680801/
• 关键词: pH; Starfish; maturation; arrest; meiosis; MAP kinase; oocyte; 細胞周期; 幻数分裂; 中期停止; 受精; Na^+; H^+アンチポーター; サイクリン; プロテアソーム; GTP結合蛋白質; P13キナーゼ

Reinitiation of meiosis in oocytes usually occurs as a two-step process during which release from the prophase block is followed by an arrest in metaphase of the first or second meiotic division (metaphase I [MI] or metaphase II [MII]). The mechanism of MI arrest in meiosis is poorly understood, although it is a widely observed phenomenon in invertebrates. The blockage of fully grown starfish oocytes in prophase of meiosis I is released by the hormone 1-methyladenine. It has been believed that meiosis of starfish oocytes proceeds completely without MI or MII arrest, even when fertilization does not occur. Here we show that MI arrest of starfish oocytes occurs in the ovary after germinal vesicle breakdown. This arrest is maintained both by the Mos/MEK/MAP kinase pathway and the blockage of an increase of intracellular pH in the ovary before spawning. Immediately after spawning into seawater, activation of Na+/H+ antiporters via a heterotrimeric G protein coupling to a 1-methyladenine receptor in the oocyte leads to an intracellular pH increase that can overcome the MI arrest even in the presence of active MAP kinase.

卵母细胞减数分裂的再起始通常分为两步，在此过程中，从前期阻滞释放后，在第一次或第二次减数分裂的中期（中期I [MI]或中期II [MII]）停止。虽然在无脊椎动物中广泛观察到减数分裂中心肌梗死停止的现象，但其机制尚不清楚。海星卵母细胞在减数分裂前期的阻滞是由激素1-甲基腺嘌呤释放的。人们一直认为，即使没有受精，海星卵母细胞的减数分裂也完全没有MI或MII停止。本研究显示，海星卵母细胞的MI阻滞发生在卵巢生发囊泡破裂后。这种抑制是通过Mos/MEK/MAP激酶途径和在产卵前阻断卵巢细胞内pH值的增加来维持的。在产卵进入海水后，通过异源三聚体G蛋白偶联到卵母细胞中的1-甲基腺嘌呤受体，激活Na+/H+反转运蛋白，导致细胞内pH升高，即使在MAP激酶活跃的情况下也能克服心肌梗死。

项目成果

Harada, K., Oita, E., Chiba, K.: "Metaphase I arrest of starfish oocytes induced via the MAP kinase pathway is released by an increase of intracellular pH"Development. (in press).

Harada, K.、Oita, E.、Chiba, K.：“通过 MAP 激酶途径诱导的海星卵母细胞的中期 I 停滞是通过细胞内 pH 值的增加来释放的”开发。

Iwasaki, H., Chiba, K., Uchiyama, T., Yoshikawa, F., Suzuki, F., Ikeda, M., Furuichi, T., and Mikoshiba, K.: "Molecular characterization of the starfish 1,4,5-trisphosphate receptor and its role during oocyte maturation and fertilization"J. Biol. Chem.. 2

Iwasaki, H.、Chiba, K.、Uchiyama, T.、Yoshikawa, F.、Suzuki, F.、Ikeda, M.、Furuichi, T. 和 Mikoshiba, K.：“海星的分子特征 1,4

Iwasaki H., Chiba, K., et al.: "Molecular characterization of the starfish 1,4,5-trisphosphate receptor and its role during oocyte maturation and fertilization"J. Biol. Chem.. 277. 2763-2772 (2002)

Iwasaki H.、Chiba, K. 等人：“海星 1,4,5-三磷酸受体的分子特征及其在卵母细胞成熟和受精过程中的作用”J.

Iwasak, H., Chiba, K. et al.: "Molecular characterization of the starfish 1, 4, 5-triphosphate receptor and its role during oocyte maturation and fertilization"J Biol. Chem.. 277. 2763-2772 (2002)

Iwasak, H., Chiba, K. 等人：“海星 1,4,5-三磷酸受体的分子特征及其在卵母细胞成熟和受精过程中的作用”J Biol。

Harada, K., Oita, E., and Chiba, K.: "Metaphase I arrest of starfish oocytes induced via the MAP kinase pathway is released by an increase of intracellular pH"Development.. in press. (2003)

Harada, K.、Oita, E. 和 Chiba, K.：“通过 MAP 激酶途径诱导的海星卵母细胞的中期 I 停滞是通过细胞内 pH 值的增加来释放的”开发..正在出版。