Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, Berlin, Germany. Electronic address: https://twitter.com/@TSchwammle.
Otto Warburg Laboratories, Max Planck Institute for Molecular Genetics, Berlin, Germany.
Curr Opin Genet Dev. 2023 Aug;81:102063. doi: 10.1016/j.gde.2023.102063. Epub 2023 Jun 23.
X-chromosome inactivation (XCI) has evolved in mammals to compensate for the difference in X-chromosomal dosage between the sexes. In placental mammals, XCI is initiated during early embryonic development through upregulation of the long noncoding RNA Xist from one randomly chosen X chromosome in each female cell. The Xist locus must thus integrate both X-linked and developmental trans-regulatory factors in a dosage-dependent manner. Furthermore, the two alleles must coordinate to ensure inactivation of exactly one X chromosome per cell. In this review, we summarize the regulatory principles that govern the onset of XCI. We go on to provide an overview over the factors that have been implicated in Xist regulation and discuss recent advances in our understanding of how Xist's cis-regulatory landscape integrates information in a precise fashion.
X 染色体失活（XCI）在哺乳动物中进化，以补偿性染色体剂量在性别之间的差异。在胎盘哺乳动物中，XCI 在胚胎发育早期通过上调每个雌性细胞中随机选择的 X 染色体上的长非编码 RNA Xist 来启动。因此，Xist 基因座必须以剂量依赖的方式整合 X 连锁和发育转录调节因子。此外，两个等位基因必须协调，以确保每个细胞中仅失活一条 X 染色体。在这篇综述中，我们总结了调控 XCI 起始的调控原则。我们接着概述了已被牵涉到 Xist 调控的因素，并讨论了我们对 Xist 顺式调控景观如何以精确的方式整合信息的理解的最新进展。
