Instability of repetitive DNA sequences: The role of replication in multiple mechanisms
Instability of repetitive DNA sequences: The role of replication in multiple mechanisms
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DOI：
10.1073/pnas.111008398
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发表时间：
2001-07-17
影响因子：
11.1
通讯作者：
Lovett, ST
中科院分区：
文献类型：
--
作者：
Bzymek, M;Lovett, ST
不同长度的串联序列同源性之间的重排是基因组变化的主要来源，并且可能对生物体有害。这些重排可能导致侧翼直接序列重复的遗传物质的缺失或重复。对大肠杆菌中重复序列不稳定性的分子遗传学分析为这些重排的潜在机制提供了一些线索。我们提出了与 RecA 无关的序列重排的三种机制的证据：简单复制滑移、姐妹染色体交换相关滑移和单链退火。我们讨论了这些机制的限制，并将它们的特性与 RecA 依赖性同源重组进行了对比。复制在两种滑动错位机制中发挥着关键作用，复制困难似乎会通过所有这些机制触发重排。
Rearrangements between tandem sequence homologies of various lengths are a major source of genomic change and can be deleterious to the organism, These rearrangements can result in either deletion or duplication of genetic material flanked by direct sequence repeats. Molecular genetic analysis of repetitive sequence instability in Escherichia coli has provided several clues to the underlying mechanisms of these rearrangements, We present evidence for three mechanisms of RecA-independent sequence rearrangements: simple replication slippage, sister-chromosome exchange-associated slippage, and single-strand annealing. We discuss the constraints of these mechanisms and contrast their properties with RecA-dependent homologous recombination. Replication plays a critical role in the two slipped misalignment mechanisms, and difficulties in replication appear to trigger rearrangements via all these mechanisms.