鼠疫耶尔森菌基因组进化与生态位适应研究

DNA microarray analysis of genome dynamics in Yersinia pestis: insight into bacterial genome microevolution and niche adaptation

目的 探索鼠疫耶尔森菌基因组进化的基本规律及其与该菌在自然界适应性演化之间的内在联系。方法 对 36株鼠疫耶尔森菌和 7株假结核耶尔森菌进行芯片比较基因组分析 ,鉴定差异区段 (DFR) ,并对 2 6 0株鼠疫耶尔森菌进行PCR验证 ,分析各DFR在这些鼠疫耶尔森菌中的分布 ,同时进行基因组岛分析。结果 在鼠疫耶尔森菌基因组中鉴定出 2 2个DFR ,基于DFR图谱 ,将鼠疫耶尔森菌中国分离株分成 14个基因组型。鼠疫耶尔森菌共有 2 1个基因组岛 ,其中 18个已存在于假结核杆菌中 ,余下 3个为鼠疫耶尔森菌独有。结论 探明了各基因组岛在鼠疫耶尔森菌和假结核耶尔森菌间的差异分布 ,探究了鼠疫耶尔森菌的起源进化 ;建立了鼠疫耶尔森菌基因组分型系统 ;建立了各基因组型别间的系统发育关系 ,初步揭示了鼠疫耶尔森菌基因组的进化规律及其与鼠疫耶尔森菌生态位适应和鼠疫疫源地扩展之间的关系 。

Objective To study the genome dynamics of Y. pestis and look for the relationship between its genome microevolution and niche adaption.Methods The DNA microarray combined with PCR was used to perform comparative genomic analysis of natural populations of Y.pestis.Results It was revealed that considerable genome dynamics of Y. pestis were the result of gene acquisition and loss in genome. We established a genomotyping system to group homologous isolates of Y. pestis, drew an outline of parallel microevolution of the Y. pestis genome, and established the link between the bacterial niche adaptation and genome microevolution.Conclusion The transmission, colonization and expansion of Y. pestis in natural foci are the results of its parallel, directional and gradual adaptation to the complex interactions among the environment, the hosts, and the pathogen itself.