David Geffen School of Medicine, Department of Biological Chemistry, Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, Jonsson Comprehensive Cancer Center, Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA.
David Geffen School of Medicine, Department of Biological Chemistry, Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, Jonsson Comprehensive Cancer Center, Molecular Biology Institute, University of California Los Angeles, Los Angeles, CA 90095, USA.
Trends Cell Biol. 2018 Dec;28(12):999-1013. doi: 10.1016/j.tcb.2018.05.005. Epub 2018 Jun 14.
In each somatic cell of a female mammal one X chromosome is transcriptionally silenced via X-chromosome inactivation (XCI), initiating early in development. Although XCI events are conserved in mouse and human postimplantation development, regulation of X-chromosome dosage in preimplantation development occurs differently. In preimplantation development, mouse embryos undergo imprinted form of XCI, yet humans lack imprinted XCI and instead regulate gene expression of both X chromosomes by dampening transcription. The long non-coding RNA Xist/XIST is expressed in mouse and human preimplantation and postimplantation development to orchestrate XCI, but its role in dampening is unclear. In this review, we discuss recent advances in our understanding of the role of Xist in X chromosome dosage compensation in mouse and human.
在雌性哺乳动物的每个体细胞中，X 染色体通过 X 染色体失活（XCI）转录沉默，这一过程发生在早期发育过程中。尽管 XCI 事件在小鼠和人类的植入后发育中是保守的，但在植入前发育中 X 染色体剂量的调节方式不同。在植入前发育中，小鼠胚胎经历印迹形式的 XCI，但人类缺乏印迹 XCI，而是通过抑制转录来调节两条 X 染色体的基因表达。长非编码 RNA Xist/XIST 在小鼠和人类的植入前和植入后发育中表达，以协调 XCI，但它在抑制中的作用尚不清楚。在这篇综述中，我们讨论了我们对 Xist 在小鼠和人类 X 染色体剂量补偿中的作用的理解的最新进展。
