The ompA gene in Chlamydia trachomatis differs in phylogeny and rate of evolution from other regions of the genome
The ompA gene in Chlamydia trachomatis differs in phylogeny and rate of evolution from other regions of the genome
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DOI：
10.1128/iai.74.1.578-585.2006
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发表时间：
2006-01-01
影响因子：
3.1
通讯作者：
Sensabaugh, GF
中科院分区：
文献类型：
--
作者：
Brunelle, BW;Sensabaugh, GF
沙眼衣原体菌株根据ompA（编码主要外膜蛋白的基因）的核苷酸序列差异分为血清型。然而，基于ompA的菌株的系统发育表征导致与沙眼衣原体病理学的区别特征不一致的血清型分组，例如，组织向性和疾病表现。我们比较了来自16个血清型的18个菌株的衣原体基因组周围多个位点的核苷酸序列;采样区域包括编码管家酶的基因（总计2，073 bp），基因间非编码片段（1，612 bp）和编码第二外膜蛋白的基因（porB; 1，023 bp），ompA序列（1，194 bp）用作参考。这些比较分析揭示了采样区域之间的核苷酸取代模式的实质性变化，平均成对序列差异范围从0.15%的管家基因ompA的12.1%。采样的基因组序列的系统发育特征得到了强烈支持的树，该树将菌株分成与沙眼衣原体生物学一致的组，并且具有与ompA树完全不同的拓扑结构。这种系统发育的不一致性可以通过不同基因组背景之间的ompA基因重组来解释。然而，我们发现，除了ompA外，没有证据表明沙眼衣原体基因组周围的任何采样区域内或之间发生重组。对pmp基因家族的四个成员发表的序列数据的平行分析与这里报道的系统发育分析一致。
Strains of Chlamydia trachomatis are classified into serovars based on nucleotide sequence differences in ompA, the gene that encodes the major outer membrane protein. Phylogenetic characterization of strains based on ompA, however, results in serovar groupings that are inconsistent with the distinguishing features of C trachomatis pathobiology, e.g., tissue tropisms and disease presentation. We have compared nucleotide sequences at multiple sites distributed around the chlamydial genome from 18 strains representing 16 serovars; sampled regions included genes encoding housekeeping enzymes (totaling 2,073 bp), intergenic noncoding segments (1,612 bp), and a gene encoding a second outer membrane protein (porB; 1,023 bp), with the ompA sequence (1,194 bp) used for reference. These comparative analyses revealed substantial variation in nucleotide substitution patterns among the sampled regions, with average pairwise sequence differences ranging from 0.15% for the housekeeping genes to 12.1% for ompA. Phylogenetic characterization of the sampled genomic sequences yielded a strongly supported tree that divides the strains into groupings consistent with C trachomatis biology and which has a topology quite distinct from the ompA tree. This phylogenetic incongruity can be accounted for by recombination of the ompA gene between different genomic backgrounds. We found, however, no evidence of recombination within or between any of the sampled regions around the C trachomatis genome apart from ompA. Parallel analysis of published sequence data on four members of the pmp gene family are consistent with the phylogenetic analyses reported here.