文档介绍：Hfq对伤寒沙门菌高渗应激早期基因表达的调节
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作者:谢新民李安平杜鸿茅凌翔罗哲王敏黄新祥
【摘要】目的: 探查伤寒沙门菌hfq基因在高渗应激早期对其他基因表达的影响。方法: 用自杀质粒介导的同源重组方法制备伤寒沙门菌hfq基因缺陷变异株;利用伤寒沙门菌全基因组芯片技术,比较伤寒沙门菌野生株和hfq基因缺陷变异株在高渗应激早期的基因表达谱差异,并选择部分表达差异基因进行实时定量PCR验证。结果: 伤寒沙门菌hfq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hfq基因缺陷变异株在高渗应激早期有62个基因表达上调,有32个基因表达下调。实时定量PCR结果与芯片分析一致。结论: Hfq作为一个调节因子在伤寒沙门菌高渗应激早期对基因表达起重要调节作用。
【关键词】伤寒沙门菌; hfq; 高渗应激; 基因芯片分析
[Abstract] Objective: To explore the influence of Hfq on gene expression regulation of serovar Typhi at earlystage of hyperosmotic : The hfq deleted mutant of serovar Typhi was prepared by homologous bination mediated by suicide plasmid; the difference of gene expression profiles betwe
en the wild strain and the hfq mutant at earlystage of hyperosmotic stress was investigated by genomic assay; qRTPCR was performed to validate the results of microarray assay. Results: The hfq deleted mutant of serovar Typhi was constructed essfully; gene expression profiles analysis revealed that expression of 62 genes and 32 genes were induced and decreased respectively in the hfq mutant at earlier stage of hyperosmotic results of qRTPCR were consistent with the results of genomic assay. Conclusion: Hfq of serovar Typhi can serve as an important factor to regulate gene expression in response to hyperosmotic stress.
[Key words] Salmonella enterica serovar Typhi; hfq; hyperosmotic stress; gene microarray
伤寒沙门菌(Salmonella enterica serovar Typhi,)是一种人类严重的肠道致病菌,已成为一种重要的原核基因表达与调控研究的模式生物。hfq基因编码的蛋白是一种分子伴侣,最早是作为大肠埃希菌RNA噬菌体Qβ复制所必需的看家因子而被发现的[1],它能够帮助小RNA(small RNAs,sRNA)与目标RNA分子结合,通过增加sRNA的稳定性,作为RNA分子伴侣在细菌的基因转录后水平调节目的基因的表达[2]。Hfq除了能稳定sRNA的结构,影响mRNA的翻译外,还能够与RNA酶E(RN
aseE)形成降解复合体,同时降解sRNA和mRNA,从而抑制目的基因的表达[3]。
目前研究表明,在鼠伤寒沙门菌(Salmonella enterica serovar Typhimurium, )中hfq基因与细菌的毒力有密切关系,hfq基因缺陷变异株的侵袭力明显下降,动力也几乎丧失[4]。伤寒沙门菌与鼠伤寒沙门菌同源性较高,而在伤寒沙门菌中,细菌在高渗应激条件下有许多与侵袭相关的基因上调[5],提示在高渗应激下伤寒沙门菌的基因表达调节