鼠疫菌102kb基因座一端IS100的缺失与pgm^+稳定性的研究

Study on the relation between the absence of one IS100 in 102 kb pgm locus of Yersinia pestis and the stability of pigmentation phenotype

目的 了解鼠疫菌102kb pgm基因座一端IS100的缺失与pgm^1稳定性的关系。方法 采用聚合酶链式反应(PCR)扩增国内各型鼠疫菌102kb pgm基因座色素沉着这一端IS100的片段,并选择克隆测序分析。结果 通过PCR扩增,其中只能扩增出约2560bp左右条带的生态型,也就是其102kb pgm基因座色素沉着这一端IS100的片段缺失,除锡林郭勒高原布氏田鼠型,还有北天山东段型、北天山西段A、B型,其pgm^+表型非常稳定;而有一部分菌株的扩增结果为阴性另一部分菌株扩增出4492bp条带的生态型,扩增出4492bp条带的菌株102kb pgm基因座色素沉着这一端有IS100,结果为阴性的菌株其整个102kb pgm基因座可能已经丢失,此种情况包括祁连山型,青藏高原型,冈底斯山型,滇西纵谷型等,其pgm^+表型表现出不稳定。结论 鼠疫菌102kb pgm基因座一侧缺失IS100的菌株,可具有较稳定的pgm^+表型,而鼠疫菌102kb pgm基因座两侧有IS100的菌株,pgm^+表型不稳定。

Objective To study the relation between the absence of one IS100 in the 102 kb pgm locus of Yersinia pestis and the stability of pigmentation phenotype(pgm'). Methods We amplified the segment including IS100 in 102 kb pgm locus of Yersinia pestis that isolated from all ecotypes in China by polymerase chain reaction(PCR). There were 171 strains isolated from 18 ecotypes in this study. One strain was chosen to be cloned and sequenced. Results Besides the type of Microtus brandti,the types of East-North Tianshan, A and B of West-Nortb Tianshan, Microtus Qinghai had one band with about 2560 bp. These strains lost one IS100 in 102 kb pgm locus of Yersinia pestis. Their pgm^+ phenotype was stable. Some strains of ecotypes from Qilian Mountain, Qinghai-Tibet Plateau, Gangdisi Mountain, West Yunnan Mountain had no bands in the PCR products. Negative strains would lose the whole 102 kb pgm locus. The others had one band with 4492 bp. These strains had two IS100 which flanked the 102 kb pgm locus but the pgm^+ phenotype was unstable. Conclusion Yersinia pestis which had only one IS100 would flank the 102 kb pgm locus and had stable pgm^+ phenotype while the Yersinia pestis that having two IS100 flanked the 102 kb pgm locus would have unstable pgm^+ phenotype.