鼠疫耶尔森菌基因组中IS100插入位点的特异性分析

Locus-specific analysis of ISIO0 insertion within Yersinia pestis genome

目的通过鼠疫耶尔森菌基因组中插入序列IS100位点的特异性研究，对我国鼠疫菌基因组的构成类型和特点进行分析。方法以鼠疫菌东方变种C092全长序列为参考，选择5个位置的IS100位点，在IS100基因相邻两外侧设计1对引物，在IS100基因内设计1对向外引物使其分别能够与两外侧引物扩增。对来自13个生态型的91株鼠疫菌和1株假结核耶尔森菌进行PCR扩增，产物进行克隆测序分析，同时把各菌株的IS100位点情况标记在我国鼠疫疫源地类型概图上进行分析。结果实验所用91株鼠疫菌在所选定IS100位点出现含有和不含IS100的插入序列，基因片段组成相对C092序列已发生改变，而且这些IS100基因型的组成在我国鼠疫自然疫源地中呈现区域性分布。结论IS100基因型别分布与我国鼠疫菌疫源地分型分布基本一致．并直接反映了鼠疫菌基因组某特定位点的基因组成状况及其在进化过程中的高度流动性。

Objective To study the genotyping distribution of the Yersinia pestis （Y.pestis） strains by characterizing the diversity of the insertion sequence IS100 within the Y.pestis genome. Methods Derived from the known sequence of oriental strain CO92, 5 pairs of locus-specific primers originating from both sides of the adjacent region of IS100 copies were designed, and two other complementary primers inside the IS100 sequence were designed to correspond with the outer primers. Then, 91 Y.pestis strains and 1 pseudotuberculosis strain were tested by the specific PCR method using the primers described above and the PCR products were conformed by the sequence analysis, then further analysis was performed after the IS100 status was marked on the map of the plague focus type of china. Results The 91 Y.pestis strains had different IS100 status in their genome on tested loci, some possessed ISI00 insertion, some didn＇t, and others changed their genome constitution. The IS100 possession on the 5 loci also suggested a distribution of regionality. Conclusion The analysis of some IS100 insertion element loci reveals that the IS100 genotyping distribution is consistent with the plague focus of type of China. And IS100 genotyping pattern of the Y.pestis stains well reflects its genome constitution and the high flowability in its natural evolution.