PmrA对伤寒沙门菌高渗应激后期基因表达调节初探

Analysis of influence of PmrA on gene expression regulation of S.enterica serover Typhi at later stage of hyperosmotic stress

目的:探讨伤寒沙门菌调节因子PmrA在高渗应激后期对基因表达调节的影响。方法:应用自杀质粒介导的同源重组方法制备伤寒沙门菌pmrA基因缺陷变异株;利用伤寒沙门菌全基因组芯片分析技术,比较伤寒沙门菌野生株和pmrA基因缺陷变异株在高渗应激后期的基因表达谱差异,并选择部分差异表达基因进行RT-RCR验证。结果:经PCR及序列分析证实,伤寒沙门菌pmrA基因缺陷变异株制备成功;基因表达谱比较分析结果表明伤寒沙门菌pmrA基因缺陷变异株在高渗应激后期有81个基因表达上调,有22个基因表达下调。结论:PmrA在伤寒沙门菌高渗应激后期的基因表达调节中发挥重要作用。

Objective ： To explore the influence of PmrA on gene expression regulation of S. enterica serover Typhi at later stage of hyperosmotic stress. Methods ： The pmrA deleted mutant of S. enterica serovar Typhi was prepared by homologous recombination mediated by suicide plasmid. The hyperosmotic stress environment was simulated by increasing the concentration of NaCl in the LB from 50 mmol/L to 300 mmol/L in vitro, and gene expression profiles of wild-type and pmrA deleted mutant of S. enterica serovar Typhi at later stage of osmotic stress were investigated by S. enterica serovar Typhi geneome microarray analysis. RTPCR was performed to prove the results of microarray in some selected genes. Results： PCR and sequencing analysis demonstrated that the pmrA deleted mutant of S. enterica serovar Typhi had been constructed successfully; gene expression profiles analysis revealed that expression of 81 genes and 22 genes were increased and decreased respectively in the pmrA mutant at later stage of hyperosmotic stress. Conclusion ： The regulator, PmrA of S. enterica serover Typhi, was important in genes expression regulation in response to hyperosmotic stress.