Comparative genomics of Rickettsia prowazekii Madrid E and Breinl strains
Comparative genomics of Rickettsia prowazekii Madrid E and Breinl strains
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DOI：
10.1128/jb.186.2.556-565.2004
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发表时间：
2004-01-01
影响因子：
3.2
通讯作者：
Ching, WM
中科院分区：
文献类型：
--
作者：
Ge, H;Chuang, YYE;Ching, WM
普氏立克次体是流行性斑疹伤寒的病原体，已造成数百万人死亡。马德里E是普拉兹基氏菌的弱毒株，而Breinl是毒毒株。马德里E的基因组DNA序列最近已经公布。为了研究马德里E（参比）和Breinl（检验）DNA之间的基因组差异，在包含马德里E的所有834个蛋白质编码基因的DNA微阵列上进行共杂交实验。在834个被评估的基因中，有24个基因在Breinl DNA中的杂交信号比马德里E DNA增加了1.5- 2.0倍，这表明大约有3%的基因存在基因组差异。据预测，这24个基因中的18个参与了不同的功能。对virB4、ftsK、rfbE、lpx、4和rpoH 5个基因的Southern blot分析表明，BreinI中存在一个额外的平行序列，这可能与观察到的杂交信号增加有关。实时逆转录- pcr研究显示上述5个基因及其他5个基因的表达均有所增加。在Breinl毒株中，除了24个基因的杂交信号升高外，其中一个基因（r084）的杂交信号仅为Madrid e的1/10，通过PCR和测序对该基因进行进一步分析发现，在Breinl毒株中，整个r084基因和部分r083基因的侧翼存在较大的缺失。这一首次立克次体DNA芯片的研究结果可能为阐明普拉兹氏菌的致病机制提供一些重要信息。
Rickeusia prowazekii, the causative agent of epidemic typhus, has been responsible for millions of human deaths. Madrid E is an attenuated strain of R. prowazekii, while Breinl is a virulent strain. The genomic DNA sequence of Madrid E has recently been published. To study the genomic variations between Madrid E (reference) and Breinl (test) DNAs, cohybridization experiments were performed on a DNA microarray containing all 834 protein-coding genes of Madrid E. Of the 834 genes assessed, 24 genes showed 1.5- to 2.0-fold increases in hybridization signals in Breinl DNA compared to Madrid E DNA, indicating the presence of genomic variations in similar to3% of the total genes. Eighteen of these 24 genes are predicted to be involved in different functions. Southern blot analysis of five genes, virB4,ftsK, rfbE, lpx,4, and rpoH, suggested the presence of an additional paralog(s) in BreinI, which might be related to the observed increase in hybridization signals. Studies by real-time reverse transcription-PCR revealed an increase in expression of the above-mentioned five genes and five other genes. In addition to the elevated hybridization signals of 24 genes observed in the Breinl strain, one gene (rp084) showed only 1/10 the hybridization signal of Madrid E. Further analysis of this gene by PCR and sequencing revealed a large deletion flanking the whole rp084 gene and part of the rp083 gene in the virulent Breinl strain. The results of this first rickettsial DNA microarray may provide some important information for the elucidation of pathogenic mechanisms of R. prowazekii.