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
Philos Trans R Soc Lond B Biol Sci. 2017 Nov 5;372(1733). doi: 10.1098/rstb.2016.0363.
The human blastocyst forms 5 days after one of the smallest human cells (the sperm) fertilizes one of the largest human cells (the egg). Depending on the sex-chromosome contribution from the sperm, the resulting embryo will either be female, with two X chromosomes (XX), or male, with an X and a Y chromosome (XY). In early development, one of the major differences between XX female and XY male embryos is the conserved process of X-chromosome inactivation (XCI), which compensates gene expression of the two female X chromosomes to match the dosage of the single X chromosome of males. Most of our understanding of the pre-XCI state and XCI establishment is based on mouse studies, but recent evidence from human pre-implantation embryo research suggests that many of the molecular steps defined in the mouse are not conserved in human. Here, we will discuss recent advances in understanding the control of X-chromosome dosage compensation in early human embryonic development and compare it to that of the mouse.This article is part of the themed issue 'X-chromosome inactivation: a tribute to Mary Lyon'.
人类囊胚形成于一个最小的人类细胞（精子）使一个最大的人类细胞（卵子）受精后的第 5 天。根据精子性染色体的贡献，由此产生的胚胎要么是女性，有两条 X 染色体（XX），要么是男性，有一条 X 染色体和一条 Y 染色体（XY）。在早期发育中，XX 女性和 XY 男性胚胎之间的主要区别之一是 X 染色体失活（XCI）的保守过程，该过程补偿了两个女性 X 染色体的基因表达，以匹配男性单个 X 染色体的剂量。我们对 XCI 前状态和 XCI 建立的大部分理解都是基于小鼠研究，但最近来自人类胚胎植入前研究的证据表明，在小鼠中定义的许多分子步骤在人类中没有保守。在这里，我们将讨论在理解早期人类胚胎发育中 X 染色体剂量补偿的控制方面的最新进展，并将其与小鼠的情况进行比较。本文是“X 染色体失活：向玛丽·莱昂致敬”主题特刊的一部分。
