The Study On The Genome Rearrangement Of Yersinia Pestis In China

Background:Plague is a kind of severe communicable disease which is caused by Yersinia pestis. Y.pestis belong to Enterobacteriaceae which is Gram-negative bacteria. As we known, Y.pestis comes from Yersinia pseudotuberculosis in origin before the year of 1500～20000. In 2001, The whole genome sequences of Y.pestis CO92 was published. After that, Deng observed the genome rearrangement in the sequence study of a plague named KIM in 2002. KIM was further fractioned to 27 segments compared with CO92. In recent years, more researchers focus their studies on the plague seaquence. After comparing the eight sequenced genomes, Liang et al found that the genomes of Y.pestis were divided into 61 relatively independent segments. These segments can change their positions and directions within the genomes caused by genome rearrangements. The plague genome consist of many conservative segments in different orders. We can assess phylogenetic relationship among different Y.pestis based on the styles of genome rearrangement. By analyzing the diversity of genome rearrangement patterns in China, we explored the valuable application of the genome rearrangement of Y.pestis in molecular epidemiology.Methods:We selected 129 different strains of Y.pestis, and designed primers according to the 8 sites on the genome sequences of Y.pestis. PCR was performed on 129 strains of Y.pestis. According to the PCR and sequencing results we analyzed the arrange style of Genome tectonics in Y.pestis.Result:The genome rearrangement patterns of Y.pestis of two ecotypes of transverse valleys of western Yunnan are consistent with that of sequenced strains. Most of the genome rearrangement patterns of the Qinghai-Xizang Plateau ecotype are the same with that of sequenced strains. The genome rearrangement patterns of Y.pestis of Gandise Mountains ecotype are much more similar with that of Nepal516 which located in the other side of Himalayan mountain. Y.pestis of ecotype of Xilin Gol Plateau have the same mainstream genome rearrangement patterns, but have two sites'difference from that of strain 91001. The mainstream genome rearrangement patterns of Y.pestis of ecotype of Qinghai-Tibet Plateau are close to that of Y.pestis of Xilin Gol Plateau ecotype. The genome rearrangement patterns of Y.pestis of ecotype of residential areas of western Yunnan and Fujian are close to that of strain CO92. The genome rearrangement patterns of Y.pestis of ecotype of Ordos Plateau are close to that of strain CO92 and KIM.Conclusion:Every ecotype of Y.pestis have their own mainstream genome rearrangement patterns on the 8 sites. The Ypestis's genome rearrangement patterns are an aspect of hereditary features. To establish the assessment system of genome rearrangement features of Y.pestis, we need to find the genome arrangement styles in more sites.