|论文题目：||Cyclin B2 Can Compensate for Cyclin B1 in Oocyte Meiosis I|
|作者：||李建①，汤济鑫①，程金妹，#Bian Hu，王毓倩，Batool Aalia，李晓宇，靳程，王秀霞，邓守龙，张妍，陈苏仁，#Wei-Ping Qian，孙青原，#Xing-Xu Huang，刘以训*|
|发表期刊：||Journal of Cell Biology|
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.