哺乳动物X染色体失活机制

哺乳动物X染色体连锁基因的剂量平衡，是通过雌性胚胎发育早期随机或印记失活一条X染色体来实现的，这是一个复杂的过程，包括：启动、计数、选择、维持等一系列的步骤。X染色体失活中心是X染色体失活的主控开关座位，调节X失活的早期事件，失活发生后，X染色体的失活状态可稳定地存在并传递给后代，这一过程涉及基因组印记的形成。此外，在雄性动物，精原细胞减数分裂早期也存在着短暂的X染色体失活现象。现对哺乳动物X染色体失活机制的最新进展进行综述。

X Chromosome Inactivation in Mammalian

In mammals, equal dosage of X-linked genes between the sexes is achieved by X chromosome inactivation in a random or imprinted manner in early embryonic development of females. It is a complex process including initiation, counting, choice and maintenance. X inactivation center is the master control locus of the X chromosome inactivation and regulates the early events of X inactivation. Once the X inactivation happened the inactivation state can be stably delivered to generations. This involves genome imprinted. In addition, in males, the X chromosome is inactivated together with Y chromosome in spermatogenic cells shortly before or during early meiotic prophase. This article reviews the recent advances in X chromosome inactivation in mammalian.