Mouse Molecular Genetics Unit, Developmental Biology Department, CNRS URA 2578, Institut Pasteur, F-75015 Paris, France.
Annu Rev Cell Dev Biol. 2011;27:611-29. doi: 10.1146/annurev-cellbio-092910-154020. Epub 2011 Jul 29.
X-chromosome inactivation, or the silencing of one X chromosome that occurs initially in the female somatic four-cell-stage embryo, is reversed during embryonic development first at the time of inner cell mass formation and again during formation of germ cell precursors. Such X-chromosome reactivation in the mouse implies the silencing of the Xist gene and the transcription of its antisense partner, Tsix, from both X chromosomes. In murine embryonic stem cells, both genes are under the transcriptional control of a series of critical pluripotency factors, namely, OCT3/4, NANOG, SOX2, KLF4, C-MYC and REX1. Although the inactive/active status of the two X chromosomes present in female human embryonic stem cells remains controversial, the reactivation of X-chromosome inactivation seems to be a signature for the naive pluripotent state.
X 染色体失活，或女性体细胞四细胞胚胎期最初发生的一条 X 染色体沉默，在胚胎发育过程中首先在内细胞团形成时被逆转，然后在生殖细胞前体形成时再次被逆转。这种小鼠 X 染色体的重新激活意味着 Xist 基因的沉默和其反义伴侣 Tsix 从两条 X 染色体上的转录。在小鼠胚胎干细胞中，这两个基因都受一系列关键多能性因子的转录控制，即 OCT3/4、NANOG、SOX2、KLF4、C-MYC 和 REX1。尽管女性人类胚胎干细胞中两条 X 染色体的失活/激活状态仍存在争议，但 X 染色体失活的重新激活似乎是原始多能状态的一个特征。
