ITGB5和MUC13基因在产肠毒素大肠杆菌抗性和易感大白仔猪间的差异表达分析

为分析仔猪腹泻抗性候选基因在大白仔猪抗性和易感个体间的差异表达情况及组织表达特异性,实验利用荧光定量PCR技术检测整合素β5(ITGB5)基因和黏蛋白13(MUC13)基因在仔猪小肠、脾脏、肺脏、胸腺、肝脏和淋巴6种组织中的表达水平以及在产肠毒素大肠杆菌(ETEC F4)抗性和易感仔猪个体间的差异表达情况。结果表明:大白仔猪ITGB5基因在6种组织中均有一定的表达,在抗性个体小肠组织中的表达量低于易感个体(P>0.05);MUC13基因在小肠中高度表达,在其他组织中表达量较低,且抗性个体的表达量显著高于易感个体(P<0.05)。由此可知,小肠组织中ITGB5基因的低表达和MUC13基因的高表达可能有助于降低致病性大肠杆菌黏附到小肠上皮细胞上,进而实现对致病性大肠杆菌的抗性。ITGB5基因和MUC13基因可能与仔猪腹泻抗性存在密切关系,都可以作为抗性候选基因用于标记辅助选择,应用于抗腹泻仔猪的选育。

Differential Expression Analysis of ITGB5 and MUC13 Genes in ETEC Resistant and Susceptible Large White Piglets

In order to investigate differential expression of the candidate genes underlying piglets’resistance to diarrhea as well as tissues specific expression between resistant and susceptible individuals in large white piglets.Real time qPCR was performed to quantify mRNAs of both ITGB5 and MUC13 genes in six tissues(small intestine,spleen,thymus,liver,lymph and lung)and to analyze their differential expression level between resistant and susceptible individuals towards Escherichia coli F4.The results showed that the ITGB5 gene was expressed in all the six tissues examined,and its expression of the small intestine in resistant individuals was lower than that in susceptible individuals,but the difference was statistically not significant(P>0.05).On the other hand,MUC13 gene was highly expressed in the small intestine,there was a low expression level in other tissues.Furthermore,the expression level of MUC13 gene in resistant individuals was significantly higher compared to susceptible individuals(P<0.05).The above results indicated that the low expression of the ITGB5 gene and high expression of the MUC13 gene may be beneficial to reduce the adhesion of pathogenic E.coli to intestinal epithelial cells,thereby achieving resistance to pathogenic E.coli.ITGB5 and MUC13 genes might be closely related to piglets’diarrhea resistance,and both can be considered as candidate genes for marker-assisted selection in selecting piglets’resistance to diarrhea in breeding program.