新发猪流行性腹泻病毒ORF3基因的遗传进化分析

ORF3 gene genetic variation analysis of porcine epidemic diarrhea virus prevailing in China

从浙江地区分离的2株代表性样品与全国范围内流行的参考毒株进行比对和遗传进化分析,结果分为4个组,代表性样品与大部分国内的毒株落入G4-2组,与国内早期CH-S毒株核苷酸(氨基酸)同源性为98.4%~98.5%(99.1%~99.6%);以华南地区为主的2011-2012年分离的毒株自成一组,与中国其他地区的毒株的同源性为95.0%~97.2%,与其余3组比较有9个核苷酸的变异。遗传进化分析表明所分离毒株与大部分中国的流行毒株属于一个基因型;以2011-2012年中国华南地区为主的毒株成为PEDV的一个新的基因型;提示2011-2012年中国流行着2种PEDV的基因型。

The geno-variation and genetic evolution of the ORF3 gene of porcine epidemic diarrhea viruses(PEDV)prevailing in China were studied.Phylogenetic analysis of the ORF3 gene from two representative PEDV isolates from Zhejiang area and 65PEDV reference strains from other area in China were conducted.The results showed that the 67 ORF3 sequences were clustered into four groups.The strains obtained from Zhejiang in the study fell into G4-2subgroup,which included the majority of strains studied.The newly obtained strains in this study were highly homologue with the CH-S strain,with a nucleotide identity of 98.4%-98.5% and a deduced amino acid identity of 99.1%-99.6%.The ORF3 gene of strains isolated from south China during 2011 and 2012 constituted G1 group,which had identities of 95.0% to 97.2%in nucleotide and unique nine nucleotide variations compared with other strains.In summary,the strains from Zhejiang area and most other strains studied were clustered into the G4-2 group,while the strains from Southern China were clustered into the G1 group,indicating that there were two different genotypes of PEDV prevailing in China during 2011 and 2012.