Department of Zoology, Banaras Hindu University, Varanasi, India.
J Cell Physiol. 2010 Jun;223(3):592-600. doi: 10.1002/jcp.22108.
Meiotic cell cycle in mammalian oocytes is a dynamic process that involves several stop/go channels. The cell cycle arrest in oocyte occurs at various stages such as diplotene, metaphase-I (M-I), metaphase-II (M-II), and so called metaphase-like arrest (M-III). Leutinizing hormone surge induces meiotic resumption from diplotene arrest in follicular microenvironment by overriding several factors responsible for the maintenance of meiotic arrest. The inhibitory factors are synthesized in oocyte or in the associated follicular somatic cells and transferred to the oocyte. The major factors include hypoxanthine, cyclic adenosine 3', 5'-monophosphate, cyclic guanosine 3', 5'-monophosphate, reactive oxygen species, protein kinase A, and protein kinase C. In the presence of active protein kinases, epidermal-like growth factors are produced that activate mitogen-activated protein kinase in cumulus granulosa cells. The maturation promoting factor, cytostatic factors, and spindle assembly checkpoint proteins are also involved in that maintenance of arrest at various stages of meiotic cell cycle in mammalian oocytes. In this review, we briefly summarize the role of these factors in the maintenance of meiotic cell cycle arrest in mammalian oocytes.
哺乳动物卵母细胞的减数分裂细胞周期是一个动态过程，涉及几个停止/启动通道。卵母细胞的细胞周期停滞发生在各种阶段，如二价体、第一次减数分裂中期（M-I）、第二次减数分裂中期（M-II）和所谓的类似中期的停滞（M-III）。促黄体激素激增通过克服负责维持减数分裂停滞的几个因素，从滤泡微环境中的二价体停滞诱导减数分裂恢复。抑制因子在卵母细胞或相关的滤泡体细胞中合成，并转移到卵母细胞中。主要因素包括次黄嘌呤、环腺苷酸 3'，5'-单磷酸、环鸟苷酸 3'，5'-单磷酸、活性氧、蛋白激酶 A 和蛋白激酶 C。在活性蛋白激酶存在的情况下，产生表皮样生长因子，激活卵丘颗粒细胞中的丝裂原激活蛋白激酶。成熟促进因子、细胞静止因子和纺锤体组装检查点蛋白也参与哺乳动物卵母细胞减数分裂细胞周期各阶段停滞的维持。在这篇综述中，我们简要总结了这些因素在维持哺乳动物卵母细胞减数分裂细胞周期停滞中的作用。
