CodY在单核细胞增生李斯特菌运动和毒力方面的作用  

The Role of CodY in the Regulation of Flagellar Motility and Virulence in Listeria monocytogenes

作　　者：张颖[1] 汤雨倩 沈怡[1] 罗勤[1] ZHANG Ying TANG Yu-qian SHEN Yi LUO Qin(Hubei Key Laboratory of Genetic Regulation and Integrative Biology, College of Life Sciences, Central China Normal University, Wuhan 430079, Chin)

机构地区：[1]华中师范大学生命科学学院遗传调控与整合生物学湖北省重点实验室,武汉430079

出　　处：《中国生物工程杂志》2017年第7期56-63,共8页China Biotechnology

基　　金：国家自然科学基金(31571931);华中师范大学中央高校基本科研业务费(CCNU15A02026)资助项目

摘　　要：目的:探究全局性转录调控因子CodY在单核细胞增生李斯特菌(Listeria monocytogenes,Lm)鞭毛运动和细菌毒力方面的作用。方法:通过同源重组的方法敲除Lm染色体上CodY的编码基因codY并成功构建缺失菌株的回复菌株;利用平板泳动法观测鞭毛运动的变化,RT-qPCR检测与鞭毛运动相关基因的转录表达;比较野生型菌株EGDe与CodY缺失菌株对细菌溶血活性、棉铃虫幼虫的半致死剂量和主要的毒力因子LLO和毒力基因调控蛋白PrfA转录表达的影响。结果:同野生型菌株相比,CodY缺失菌株鞭毛运动和相关基因,以及主要的毒力因子LLO和PrfA的转录表达显著降低(P≤0.01),溶血活性显著降低(P≤0.01),对棉铃虫幼虫的半致死剂量上升了5.8倍。结论:CodY在Lm鞭毛运动和细菌毒力调控方面具有重要作用。Objective ：To explore the function of the transcription factor CodY on flagellar motility, bacterial virulencein Listeria mortocytogenes. Methods： The codY gene on the L. monocytogenes chromosome was knocked out by homologous recombination and the strain of the deleted codY gene was successfully complemented by the codY gene construct; the results were evaluated by observation of the motilityof flagellar movement, the transcriptional expression of flagellum-related genes with RT-qPCR. The effects of wild-type strain EGDe and CodY-deficient strain on bacterial hemolytic activity, semi-lethal dose of Helicoverpa armigera and the main virulence factor LLO （coding gene hly） and virulence regulatory protein PrfA （coding gene poCA ） transcription expression profiles were compared. Results： Compared with the wild-type strain, the CodY-deficient strain showed a significant reduction in the flagellar movement, the hemolytic activity, as well as the transcriptional expression of flagellum-related genes and the major virulence genes hly and pocA（P≤O. 01 ） ; while the semi-lethal dose on Helicoverpa armigera （Htibner） was increased 5.8 fold. Conclusion：The CodY plays an important role in flagellar motility and transcription regulation ofbacterial virulence in Listeria monocytogenes.

关 键 词：单核细胞增生李斯特菌 CodY 鞭毛运动 毒力 

分 类 号：Q815[生物学—生物工程]