Department of Genetics, Yale Stem Cell Center, Yale School of Medicine, New Haven, CT, USA.
Cell Cycle. 2012 Jan 15;11(2):229-35. doi: 10.4161/cc.11.2.18998.
X-chromosome inactivation (XCI) is an important mechanism employed by mammalian XX female cells to level X-linked gene expression with that of male XY cells. XCI occurs early in development as the pluripotent cells of the inner cell mass (ICM) in blastocysts successively differentiate into cells of all three germ layers. X-chromosome reactivation (XCR), the reversal of XCI, is critical for germ cell formation as a mechanism to diversify the X-chromosome gene pool. Here we review the characterization of XCR, and further explore its natural occurrence during development and the in vitro models of cellular reprogramming. We also review the key regulators involved in XCI for their role in suppressing the active histone marks and the genes in the active chromosome for their inhibition of X inactivation signals.
X 染色体失活（XCI）是哺乳动物 XX 雌性细胞用来平衡 X 连锁基因表达与雄性 XY 细胞的重要机制。XCI 发生在早期胚胎发育中，当囊胚中的内细胞团（ICM）多能细胞相继分化为三个胚层的细胞时。X 染色体重新激活（XCR），即 XCI 的逆转，对于生殖细胞的形成至关重要，是一种使 X 染色体基因库多样化的机制。在这里，我们综述了 XCR 的特征，并进一步探讨了它在发育过程中的自然发生以及细胞重编程的体外模型。我们还综述了 XCI 中涉及的关键调节因子，因为它们在抑制活性组蛋白标记和活性染色体上的基因方面发挥作用，以抑制 X 失活信号。
