2015-2018年广东省猪流行性腹泻病毒M基因的遗传进化分析

Genetic Evolution Analysis for M Gene of Porcine Epidemic Diarrhea Virus from 2016-2018 in Guangdong Province

本试验通过对22株采集于2015-2018年广东省内猪流行性腹泻病毒(PEDV)流行株的M基因进行克隆和测序,并将测序结果与NCBI中PEDV参考株M基因进行同源性分析和构建系统进化树,从而了解广东省PEDV流行株的近年来遗传变异情况。结果显示,22株PEDV流行株间核苷酸序列同源性为97.5%~100.0%,与华南地区参考株M基因核苷酸序列同源性为97.7%~99.9%,与国内较早分离株CH/S和经典毒株CV777同源性较低,分别为97.5%~98.1%、97.7%~98.2%。PEDV M基因遗传进化分析显示,22株广东PEDV流行株的同源性较高,亲缘关系紧密,此外,22株广东PEDV流行株与大部分代表性毒株、疫苗株亲缘关系较远,如国内早期分离株CH/S、经典毒株CV777、韩国株KRPEDV-9-Vaccine、泰国株MNIAH10054108、日本株JMe2、英国株Brl/87等。试验结果表明,广东省当前的PEDV流行毒株存在基因变异并形成独特进化分支。

In this study, M genes of 22 epidemic diarrhea virus(PEDV) epidemic strains isolated from Guangdong province between 2015 to 2018 were cloned and sequenced to acquaint with the genetic variation conditions of PEDV. The results of sequence alignment and analysis showed that the nucleotide sequence homologies were 97.5%~100.0% between the 22 PEDV isolates, and were 97.7%~99.9% among the 22 PEDV isolates and the reference strains of South China, but the homology among of the 22 PEDV isolates with the earlier domestic isolates CH/S and the classical strains CV777 was lower, which was 97.5%~98.1% and 97.7%~98.2%, respectively. The results of genetic evolution analysis of PEDV M gene showed the 22 isolates had close phylogenetic relationship,while they were far from the most representative strains and vaccine strains, such as early isolates CH/S of China, vaccine strains CV777,krpedv-9-vaccine strain of South Korean, MNIAH10054108 strain of Thai, JMe2 strain of Japanese, Brl/87 strain of British and so on. The results reveal that the current prevalent PEDV in Guangdong has gene variation to form a unique evolutionary branch.