Widespread recombination throughout Wolbachia genomes
Widespread recombination throughout Wolbachia genomes
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DOI：
10.1093/molbev/msj049
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发表时间：
2006-02-01
影响因子：
10.7
通讯作者：
Werren, JH
中科院分区：
文献类型：
--
作者：
Baldo, L;Bordenstein, S;Werren, JH
越来越多的证据表明，同源重组是密切相关的自由生活的细菌之间的遗传变异性的一个强大来源。在这里，我们调查的范围内共生细菌沃尔巴克氏体的管家基因之间的重组。四个管家基因，gltA，dnaA，ftsZ。和groEL，从属于超群A和B的22个菌株的样品中测序。使用系统发育推断、遗传变异分析和四种重组检测程序（MaxChi、Chimera、RDP和Geneconv）搜索基因内和基因间的重组序列比对。独立的分析表明，没有或弱ftsZ，dnaA，和groEL基因内重组。基因内重组影响gltA，明确的证据表明，不同的沃尔巴克氏体超群内和之间的水平DNA转移。在所有基因对之间检测到基因间重组，表明包含几个基因的基因组部分的水平交换或涉及沿基因组沿着的较小片段的多个重组事件。总的来说，观察到的模式是兼容的普遍重组。这样的结果与先前的表面蛋白噬菌体中重组的证据和IS元件相结合，支持沃尔巴克氏体菌株的所有意想不到的嵌合起源，对沃尔巴克氏体的发生和这些专性细胞内细菌在节肢动物中的适应具有重要意义。
Evidence is growing that homologous recombination is a powerful source of genetic variability among closely related free-living bacteria. Here we investigate the extent of recombination among housekeeping genes of the endosymbiotic bacteria Wolbachia. Four housekeeping genes, gltA, dnaA, ftsZ. and groEL, were sequenced from a sample of 22 strains belonging to supergroups A and B. Sequence alignments were searched for recombination within and between genes Using Phylogenetic inference, analysis of genetic variation, and four recombination detection programs (MaxChi, Chimera, RDP, and Geneconv). Independent analyses indicate no or weak intragenic recombination in ftsZ, dnaA, and groEL. Intragenic recombination affects gltA, with a clear evidence of horizontal DNA transfers within and between divergent Wolbachia supergroups. Intergenic recombination was detected between all pairs of genes, suggesting either a horizontal exchange of a genome portion encompassing several genes or multiple recombination events involving smaller tracts along the genome. Overall, the observed pattern is compatible with pervasive recombination. Such result combined with previous evidence of recombination in a surface protein phage, and IS elements, Support all unexpected chimeric origin of Wolbachia strains, with important implications for Wolbachia phylogeny and adaptation of these obligate intracellular bacteria in arthropods.