鼠伤寒沙门菌sRNA SdsR靶基因的预测及验证分析

Prediction and Verification of sRNA SdsR Target Genes in Salmonella typhimurium

【目的】筛选鼠伤寒沙门菌sRNA SdsR的靶基因,为明确s RNA与靶基因的互作以及沙门菌的致病机制奠定基础。【方法】利用TargetRNA2软件预测sRNA SdsR的靶标,基于前期的s RNA SdsR敲除后转录组测序结果,将预测到的基因注释到GO、KEGG以及eggNOG数据库中进行分析,通过RT-qPCR对预测到的杂交能量较高的部分靶基因进行验证。【结果】TargetRNA2软件预测到29个靶标,其中hemA、STM0951、mreC、STM1252、dcoC的杂交能量较高,且能与sRNA SdsR有连续的碱基匹配,分别与鼠伤寒沙门菌血红素合成、氧化还原过程、草酰乙酸脱羧酶的合成、膜的组成部分、细胞质蛋白的合成有关。RT-qPCR结果显示,相对于野生菌株3409,敲除s RNA SdsR后hemA、mreC的表达分别下调0.70和0.39倍;STM0951、STM1252、dcoC的表达分别上调0.51、0.35和1.86倍。【结论】hemA、STM0951、mreC、STM1252、dcoC基因很可能受s RNA SdsR的直接调控且对某些靶基因的表达有促进作用。

【Objective】Target genes of Salmonella Typhimurium sRNA SdsR were investigated to further understand the interactions between the sRNA and the target genes as well as the pathogenic mechanism of S.typhimurium.【Method】The TargetRNA2 software was used to predict the target of sRNA SdsR in the pathogen.According to the results obtained in a previous sRNA SdsR knock-out transcriptome sequencing study,the predicted genes were annotated into GO,KEGG,and eggNOG databases for analysis.Those with high hybridization energy were further verified by RT-qPCR.【Result】There were 29 targets predicted by TargetRNA2.Among them,hemA,STM0951,mreC,STM1252,and dcoC showed high hybridization energy with a possibility of having a continuous base to match the sRNA SdsR.They might be associated with the heme synthesis,redox process,oxaloacetate decarboxylase synthesis,and membrane components and cytoplasmic protein synthesis in S.typhimurium.The RT-qPCR showed,after sRNA SdsR knockout,hemA to be downregulated by 0.70 times and mreC 0.39 times,while STM0951,STM1252,and dcoC upregulated by 0.51,0.35 and 1.86 times,respectively,over the wild strain 3409.【Conclusion】It appeared that the genes identified in this study,including hemA,STM0951,mreC,STM1252and dcoC,could directly be regulated by the sRNA SdsR and might affect the expressions of some target genes.