Focus on Meiosis Stops and starts in mammalian oocytes: recent advances in understanding the regulation of meiotic arrest and oocyte maturation
Focus on Meiosis Stops and starts in mammalian oocytes: recent advances in understanding the regulation of meiotic arrest and oocyte maturation
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发表时间：
2005
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通讯作者：
L. Mehlmann
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作者：
L. Mehlmann
哺乳动物卵母细胞在卵泡内生长和减数分裂。卵母细胞停滞在fi第一次减数分裂前期，由周围的卵泡细胞保持在减数分裂停滞状态，直到脑下分泌的黄体生成素激增刺激未成熟的卵母细胞恢复减数分裂。减数分裂的停滞依赖于卵母细胞内高水平的cAMP。这种cAMP是由卵母细胞通过G蛋白偶联受体GPR3刺激G S G蛋白产生的。黄体生成素对减数分裂成熟的刺激是通过对周围的体细胞而不是卵母细胞本身的作用来实现的。促黄体生成素诱导壁状颗粒细胞中表皮生长因子样蛋白的表达，作用于卵丘细胞以触发卵母细胞成熟。然而，卵丘细胞和卵母细胞之间的信号通路仍不清楚。这篇综述着重于最近的研究，强调了卵母细胞在产生cAMP以维持停滞中的重要性，并讨论了在卵母细胞水平上可能的靶点，在这些靶点上，黄体生成素可以刺激减数分裂恢复。
Mammalian oocytes grow and undergo meiosis within ovarian follicles. Oocytes are arrested at the first meiotic prophase, held in meiotic arrest by the surrounding follicle cells until a surge of LH from the pituitary stimulates the immature oocyte to resume meiosis. Meiotic arrest depends on a high level of cAMP within the oocyte. This cAMP is generated by the oocyte, through the stimulation of the G s G-protein by the G-protein-coupled receptor, GPR3. Stimulation of meiotic maturation by LH occurs via its action on the surrounding somatic cells rather than on the oocyte itself. LH induces the expression of epidermal growth factor-like proteins in the mural granulosa cells that act on the cumulus cells to trigger oocyte maturation. The signaling pathway between the cumulus cells and the oocyte, however, remains unknown. This review focuses on recent studies highlighting the importance of the oocyte in producing cAMP to maintain arrest, and discusses possible targets at the level of the oocyte on which LH could act to stimulate meiotic resumption.