Evolutionary implications of the frequent horizontal transfer of mismatch repair genes
Evolutionary implications of the frequent horizontal transfer of mismatch repair genes
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DOI：
10.1016/s0092-8674(00)00175-6
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发表时间：
2000-11-22
期刊：
影响因子：
64.5
通讯作者：
Matic, I
中科院分区：
文献类型：
--
作者：
Denamur, E;Lecointre, G;Matic, I
突变和随后的重组事件创造了遗传多样性，而遗传多样性受到自然选择的影响。细菌错配修复（MMR）缺陷突变体表现出高突变和同源重组率，在自然群体中经常发现。因此，我们探索了自然界中出现的 MMR 缺陷是否在细菌基因组序列中留下了一些“印记”的可能性。天然大肠杆菌分离株的 MMR 基因的比较分子系统发育表明，与管家基因相比，单个功能性 MMR 基因表现出源自不同系统发育谱系的高序列嵌合性。这种明显的水平基因转移与 MMR 缺陷突变体的超重组表型相关。 MMR 基因的序列嵌合可能是适应性进化机制的标志，该机制涉及通过 MMR 基因功能的反复丢失和重新获得来调节突变和重组率。
Mutation and subsequent recombination events create genetic diversity, which is subjected to natural selection. Bacterial mismatch repair (MMR) deficient mutants, exhibiting high mutation and homeologous recombination rates, are frequently found in natural populations. Therefore, we have explored the possibility that MMR deficiency emerging in nature has left some "imprint" in the sequence of bacterial genomes. Comparative molecular phylogeny of MMR genes from natural Escherichia coli isolates shows that, compared to housekeeping genes, individual functional MMR genes exhibit high sequence mosaicism derived from diverse phylogenetic lineages. This apparent horizontal gene transfer correlates with hyperrecombination phenotype of MMR-deficient mutators. The sequence mosaicism of MMR genes may be a hallmark of a mechanism of adaptive evolution that involves modulation of mutation and recombination rates by recurrent losses and reacquisitions of MMR gene functions.