早期染色体变化与X染色体不活化的关系
Jan Jakub Żylicz1, Aurélie Bousard2, Kristina Žumer3
1Institut Curie, PSL Research University, CNRS UMR3215, INSERM U934, UPMC Paris-Sorbonne, 75005 Paris, France; University of Cambridge, Department of Physiology, Development and Neuroscience, Cambridge CB2 3EG, UK.
Cell
|January 1, 2019
概括
这项研究揭示了X染色体无活化 (XCI) 期间最早的染色质变化,确定了基因组脱乙烯化和H2AK119无化作为关键事件. 这些涉及HDAC3和PRC1的修改对于启动女性细胞的基因沉默至关重要.
科学领域:
- 表观遗传学和基因调控
- 发育生物学
- 染色体生物学
背景情况:
- 在发育过程中转录和染色质修饰之间的相互作用尚未完全理解.
- X染色体失活 (XCI) 为研究基因沉默机制提供了一个模型系统.
- 在XCI启动过程中染色质变化的时间动态需要详细的研究.
研究的目的:
- 阐明X染色体失活 (XCI) 开始过程中的染色体修饰的精确序列和作用.
- 确定XCI期间参与早期基因沉默的关键分子参与者.
- 了解导致稳定基因沉默的表观遗传事件的层次.
主要方法:
- 使用雌性小鼠胚胎干细胞通过诱导Xist表达来启动XCI.
- 采用基因特异性分析来监测转录和染色质修饰的时间变化.
- 研究了HDAC3等特定酶和PRC1和PRC2等蛋白质复合物的作用.
主要成果:
- 在XCI过程中,最早的染色体变化被确定为基因组脱乙烯和H2AK119无化.
- HDAC3 预先结合到 X 染色体,对于 Xist 涂层的有效基因沉默至关重要.
- 与PRC1相关的H2AK119Ub和与PRC2相关的H3K27me3在基因间域中积累并传播到基因中,这取决于基因脱乙烯和沉默.
结论:
- 在XCI启动过程中建立了清晰的染色体事件等级.
- 在转录沉默的早期阶段证明了基因素脱乙和H2AK119无处不在的关键作用.
- 突出了染色质修饰在启动发育基因沉默过程中的重要性.
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