关键词: 鼠疫耶尔森菌, 质粒, 结构

Abstract:

Objective To study the features of gene composition and distribution of three common plasmids among different Yersinia pestis strains. Methods The global structure of three plasmids, pMT1, pCD1, and pPCP1, in the nine Y. pestis strains with completed whole genome sequencing was comparatively analyzed by homologous alignment of coding sequences and automatic analysis using the Mauve software. Results The pMT1 of Y. pestis showed rearrangement of large gene fragments, and it was divided into four major gene blocks. The plasmid structures of pMT1 in Orientalis Biovar strain CO92, Medievalis Biovar strain KIM, and Microtus Biovar strain 91001 were different from each other. The plasmid structures of pMT1 in all the other six Antiqua Biovar strains were almost identical, yet different from those of CO92, KIM, and 91001. Plasmid pCD1 was divided into three major gene blocks;however, the global structure of the plasmid was the same among all strains except a different insertion position of IS100. The order and orientation of all coding sequences in plasmid pPCP1 were consistent in all strains. Conclusion Plasmids pCD1 and pPCP1 have conservative gene structure among different Y. pestis strains. A certain degree of variation in the plasmid structure of pMT1 has occurred during the long-term evolution of Y. pestis.

Key words: Y. pestis, Plasmid, Structure