确保在小鼠伪自体区域中形成 meiotic DNA 断裂
Laurent Acquaviva1, Michiel Boekhout2,3, Mehmet E Karasu2,4,5
1Molecular Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA. acquavil@mskcc.org.
Nature
|May 29, 2020
概括
研究人员确定了控制性染色体伪自体区域 (PAR) 重组的因素. 这一区域对于雄性半球变异至关重要,并且需要特定的蛋白质来形成双链断裂 (DSB).
科学领域:
- 遗传学
- 分子生物学
- 生殖生物学
背景情况:
- 大多数雌性哺乳动物的性别染色体共享一个同类的伪自体区域 (PAR),这对半体分离至关重要.
- 确保在PAR内进行重组的机制在很大程度上是未知的.
研究的目的:
- 为了阐明 PAR 的动态超结构.
- 为了确定调节PAR重组的cis和trans作用因子.
- 了解男性半变异过程中PAR重组的性二态控制.
主要方法:
- 在雄性小鼠基因组中对 PAR 的动态超结构分析.
- 识别DSB促进因素及其定位.
- 研究MEI4,ANKRD31,REC8和HORMAD1蛋白质的作用.
- 试验对卵细胞中的突触进行操纵,以评估其对DSB形成的影响.
主要成果:
- 由于过度积累的DSB促进因子,PAR是雄性小鼠基因组中最容易重组的区域.
- 在DSB形成之前,PAR染色体轴延长,姐妹染色体分离,与异色微卫星阵列连接.
- 需要MEI4和ANKRD31,而REC8和HORMAD1对于这些早期的PAR事件是不必要的.
- 在卵细胞中延迟或阻止的突触可以诱导PAR中类似精子细胞的DSB水平.
- 性二态PAR行为源于PAR成熟,DSB形成和突触的动态差异.
结论:
- 在PAR中重复的DNA序列创建了对重组至关重要的独特的染色体结构.
- 在变化过程中建立了性染色体重组的机制范式.
- PAR结构成熟,DSB形成和突触之间的动态相互作用是性二态重组模式的基础.
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