Cyclin B2 can compensate for Cyclin B1 in oocyte meiosis I

作者：Jian Li, Ji‐Xin Tang, Jinmei Cheng, Bian Hu, Yuqian Wang, Aalia Batool, Xiaoyu Li, Cheng Jin, Xiuxia Wang, Shoulong Deng, Yan Zhang, Su‐Ren Chen, Weiping Qian, Qing‐Yuan Sun, Xingxu Huang, Yi-Xun Liu · 发表于：The Journal of Cell Biology · 年份：2018 · DOI：10.1083/jcb.201802077 · 被引用次数：68 · 研究领域：Reproductive Biology and Fertility、Epigenetics and DNA Methylation、Microtubule and mitosis dynamics

Mammalian oocytes are arrested at the prophase of the first meiotic division for months and even years, depending on species. Meiotic resumption of fully grown oocytes requires activation of M-phase–promoting factor (MPF), which is composed of Cyclin B1 and cyclin-dependent kinase 1 (CDK1). It has long been believed that Cyclin B1 synthesis/accumulation and its interaction with CDK1 is a prerequisite for MPF activation in oocytes. In this study, we revealed that oocyte meiotic resumption occurred in the absence of Cyclin B1. Ccnb1-null oocytes resumed meiosis and extruded the first polar body. Without Cyclin B1, CDK1 could be activated by up-regulated Cyclin B2. Ccnb1 and Ccnb2 double knockout permanently arrested the oocytes at the prophase of the first meiotic division. Oocyte-specific Ccnb1-null female mice were infertile due to failed MPF activity elevation and thus premature interphase-like stage entry in the second meiotic division. These results have revealed a hidden compensatory mechanism between Cyclin B1 and Cyclin B2 in regulating MPF and oocyte meiotic resumption.