Non-homologous end joining shapes the genomic rearrangement landscape of chromothripsis from mitotic errors.
Non-homologous end joining shapes the genomic rearrangement landscape of chromothripsis from mitotic errors.
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非同源末端连接塑造了有丝分裂错误导致的染色体碎裂的基因组重排景观。
DOI：
10.1101/2023.08.10.552800
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Ly,Peter
中科院分区：
文献类型：
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作者：
Hu,Qing;Valle-Inclan,JoseEspejo;Dahiya,Rashmi;Guyer,Alison;Mazzagatti,Alice;Maurais,ElizabethG;Engel,JustinL;Cortés-Ciriano,Isidro;Ly,Peter
有丝分裂错误产生的微核截留错误分离的染色体，这是容易发生灾难性的碎片通过chromothripsis。通过易错DNA双链断裂（DSB）修复的片段化染色体的重新组装产生与人类疾病相关的多种基因组重排。特定的修复途径如何识别和处理这些病变仍然知之甚少。在这里，我们使用CRISPR/Cas9系统地分析不同的DSB修复途径，并询问片段化染色体的重排情况。典型的非同源末端连接（NHEJ）组件的删除大大减少了复杂的重排，并向简单的改变没有chromothripsis的特征模式的重排景观。在重新掺入细胞核后，片段化的染色体定位于亚核微核体（MN体）内，并在单个细胞周期内通过NHEJ进行连接。在没有NHEJ的情况下，染色体片段很少通过替代的末端连接或基于重组的机制参与，导致延迟的修复动力学，持久的53 BP 1标记的MN体和细胞周期停滞。因此，我们提供的证据支持NHEJ作为唯一的DSB修复途径产生复杂的有丝分裂错误的重排。
Mitotic errors generate micronuclei entrapping mis-segregated chromosomes, which are susceptible to catastrophic fragmentation through chromothripsis. The reassembly of fragmented chromosomes by error-prone DNA double-strand break (DSB) repair generates diverse genomic rearrangements associated with human diseases. How specific repair pathways recognize and process these lesions remains poorly understood. Here we use CRISPR/Cas9 to systematically inactivate distinct DSB repair pathways and interrogate the rearrangement landscape of fragmented chromosomes. Deletion of canonical non-homologous end joining (NHEJ) components substantially reduces complex rearrangements and shifts the rearrangement landscape toward simple alterations without the characteristic patterns of chromothripsis. Following reincorporation into the nucleus, fragmented chromosomes localize within sub-nuclear micronuclei bodies (MN bodies) and undergo ligation by NHEJ within a single cell cycle. In the absence of NHEJ, chromosome fragments are rarely engaged by alternative end-joining or recombination-based mechanisms, resulting in delayed repair kinetics, persistent 53BP1-labeled MN bodies, and cell cycle arrest. Thus, we provide evidence supporting NHEJ as the exclusive DSB repair pathway generating complex rearrangements from mitotic errors.