The relevance of chromatin architecture to genome rearrangements in Drosophila.
The relevance of chromatin architecture to genome rearrangements in Drosophila.
复制标题
果蝇染色质结构与基因组重排的相关性。
DOI：
10.1098/rstb.2021.0206
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Schaeffer,StephenW
中科院分区：
文献类型：
--
作者：
Wright,Dynisty;Schaeffer,StephenW
核内染色体内的DNA非随机地组织成染色体区域、隔间和拓扑相关区域(TADS)。染色体重排有可能改变染色质组织和改变基因表达，从而针对这些结构变异进行选择。果蝇有大量自然发生的基因排列，这些基因排列是由两个染色体断裂以相反顺序重新加入中心区而引起的重叠倒位突变产生的。与人类不同，果蝇变异杂合子在减数分裂过程中不会产生与交换有关的负面影响，因为雄性利用基节伴侣机制进行适当的分离，而雌性产生的异常重组减数分裂产物会在极体中丢失。结果发现，果蝇种群具有广泛的倒位多态。然而，目前尚不清楚染色质结构是否限制了哪些反转断点在种群中持续存在。我们绘制了七个倒位Ind的断点。在TAD图上进行伪暗处理，以确定持续反转断点是否更有可能出现在TAD之间的边界上。我们的结果表明，断点发生在TAD边界的几率比预期的要高。一些断裂点可能会改变TADS内的基因表达，支持位置效应有助于倒位建立的假说。这篇文章是《超基因的基因组结构：原因和进化后果》主题的一部分。
DNA within chromosomes in the nucleus is non-randomly organized into chromosome territories, compartments and topologically associated domains (TADs). Chromosomal rearrangements have the potential to alter chromatin organization and modify gene expression leading to selection against these structural variants.Drosophila pseudoobscurahas a wealth of naturally occurring gene arrangements that were generated by overlapping inversion mutations caused by two chromosomal breaks that rejoin the central region in reverse order. Unlike humans,Drosophilainversion heterozygotes do not have negative effects associated with crossing over during meiosis because males use achiasmate mechanisms for proper segregation, and aberrant recombinant meiotic products generated in females are lost in polar bodies. As a result,Drosophilapopulations are found to harbour extensive inversion polymorphisms. It is not clear, however, whether chromatin architecture constrains which inversions breakpoints persist in populations. We mapped the breakpoints of seven inversions inD. pseudoobscurato the TAD map to determine if persisting inversion breakpoints are more likely to occur at boundaries between TADs. Our results show that breakpoints occur at TAD boundaries more than expected by chance. Some breakpoints may alter gene expression within TADs supporting the hypothesis that position effects contribute to inversion establishment.This article is part of the theme issue ‘Genomic architecture of supergenes: causes and evolutionary consequences’.