Comparative whole-genome analysis of virulent and avirulent strains of Porphyromonas gingivalis
Comparative whole-genome analysis of virulent and avirulent strains of Porphyromonas gingivalis
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DOI：
10.1128/jb.186.16.5473-5479.2004
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发表时间：
2004-08-01
影响因子：
3.2
通讯作者：
Duncan, MJ
中科院分区：
文献类型：
--
作者：
Chen, T;Hosogi, Y;Duncan, MJ
我们使用牙龈卟啉单胞菌基因芯片来比较有毒力的菌株W83和无毒力的标准菌株ATCC 33277的总基因含量。信号比值和散点图表明，染色体非常相似，大约93%的预测基因是相同的，而其中至少7%的基因在ATCC 33277中显示出非常低的信号或无信号。通过聚合酶链反应（PCR）对芯片结果进行验证表明，几个不同的基因在ATCC 33277中要么缺失要么发生变异。差异特征包括已报道的插入序列和ragB，以及其他假定的和已确定功能的基因。后者中的几个基因在W83中组成一个假定的操纵子，并编码参与荚膜多糖合成的酶。另一个基因簇与染色体上两个低G + C含量（41%，而整个基因组的G + C含量为48%）的旁系同源区域相关。这些区域还包含保守的和物种特异性的假定基因、转座子、插入序列和整合酶，并且位于转运RNA（tRNA）基因附近；因此，它们具有毒力岛的几个特征。虽然这种全面的比较分析显示了W83和ATCC 33277之间的密切关系，但在W83中存在但在ATCC 33277中不同或缺失的基因的聚类表明可能通过侧向基因转移获得的染色体岛的存在。
We used Porphyromonas gingivalis gene microarrays to compare the total gene contents of the virulent strain W83 and the avirulent type strain, ATCC 33277. Signal ratios and scatter plots indicated that the chromosomes were very similar, with approximately 93% of the predicted genes in common, while at least 7% of them showed very low or no signals in ATCC 33277. Verification of the array results by PCR indicated that several of the disparate genes were either absent from or variant in ATCC 33277. Divergent features included already reported insertion sequences and ragB, as well as additional hypothetical and functionally assigned genes. Several of the latter were organized in a putative operon in W83 and encoded enzymes involved in capsular polysaccharide synthesis. Another cluster was associated with two paralogous regions of the chromosome with a low G+C content, at 41%, compared to that of the whole genome, at 48%. These regions also contained conserved and species-specific hypothetical genes, transposons, insertion sequences, and integrases and were located adjacent to tRNA genes; thus, they had several characteristics of pathogenicity islands. While this global comparative analysis showed the close relationship between W83 and ATCC 33277, the clustering of genes that are present in W83 but divergent in or absent from ATCC 33277 is suggestive of chromosomal islands that may have been acquired by lateral gene transfer.