霍克斯基因的多镇压涉及空间反,但不涉及域紧缩或相位过渡
Sedona Eve Murphy1,2,3, Alistair Nicol Boettiger4
1Department of Genetics, Stanford University, Stanford, CA, USA.
Nature genetics
|February 16, 2024
概括
多组蛋白在发育过程中使基因沉默. 新的研究表明,即使在解压时,Polycomb-bound 染色质仍然被抑制,这挑战了压缩和相分离模型.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 基因组学就是基因组学.
背景情况:
- 多组蛋白对于发育过程中的转录沉默至关重要.
- 现有的模型建议通过Polycomb蛋白质进行染色质紧缩或液体-液体相分离,从而导致基因抑制.
- 这些模型表明,被抑制的基因采用了紧的球状状态.
研究的目的:
- 研究基因组折叠和Polycomb蛋白在转录抑制中的作用.
- 为了测试压缩压缩和相分离模型的有效性,用于Polycomb-dependent基因沉默.
- 了解Polycomb目标基因的动态色素结构.
主要方法:
- 利用光学重建染色体架构 (ORCA) 来分析数千个单细胞中的Hoxa基因集群.
- 采用聚合物模拟来建模染色体行为和表观遗传状态传播.
- 检查了多种细胞类型的染色质结构,以确定保存的机制.
主要成果:
- 聚合物结合的染色质经常存在于解压状态,并且部分与邻近的染色质混合.
- 尽管缺乏全球染色质紧缩,但仍保持了转录抑制.
- 观察到的染色质动态与简单的压缩-通过-紧缩或相位分离模型不一致.
- 聚合物模拟支持"空间反"模型,涉及用于表观遗传记忆传播的短暂接触.
结论:
- 这些发现挑战了Polycomb介导基因沉默的既定模型.
- 染色体分解和部分混合并不排除稳定的转录抑制.
- 一种涉及短暂接触的"空间反"模型解释了表观遗传记忆,而不需要球状紧缩.
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