X 无活化计数和选择是一个随机的过程:证据表明X链接激活器的参与
Kim Monkhorst1, Iris Jonkers, Eveline Rentmeester
1Department of Cell Biology, Erasmus Medical Center, P.O. Box 2040, Rotterdam 3000 CA, The Netherlands; Department of Reproduction and Development, Erasmus Medical Center, P.O. Box 2040, Rotterdam 3000 CA, The Netherlands.
Cell
|February 13, 2008
概括
雌性哺乳动物细胞使用X染色体失活 (XCI) 来补偿基因剂量. 这项研究揭示了一种随机机制,每个X染色体独立地根据其与细胞 ploidy 的比率启动XCI.
科学领域:
- 遗传学 是一个遗传学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 发展生物学 发展生物学
背景情况:
- 雌性哺乳动物的剂量补偿通过X染色体失活 (XCI) 来实现.
- 在XCI启动期间X染色体计数和选择的精确机制仍然不完全理解.
- 现有的模型不能完全解释在多倍体细胞中观察到的XCI启动的独立概率.
研究的目的:
- 研究X染色体失活 (XCI) 的启动机制.
- 确定在早期发育过程中X染色体计数和选择是如何调节的.
- 阐明X链系因子在XCI启动中的作用.
主要方法:
- 在四倍体XXXX,XXXY和XXYY胚胎干细胞中分析XCI.
- 调查每X染色体XCI启动的概率.
- 检查删除一个关键区域 (包括Xist,Tix和Xite) 对XCI的影响.
主要成果:
- 核中的每个X染色体都具有独立的XCI启动概率.
- 发病XCI的概率与X染色体与ploidy的比率成正比.
- 即使Xist/Tsix/Xite区域被删除后,XCI也会发生,这表明存在其他X相关因子.
结论:
- XCI启动遵循一个随机机制,每个X染色体独立地起作用.
- 一个X编码的激活器,根据XCI本身,可能会调节失活的概率.
- 这些发现支持了一个模型,在这个模型中,被删除区域之外的转作用因素协调了XCI启动.
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