4株猪流行性腹泻病毒S1基因生物信息学分析

为分析猪流行性腹泻病毒（porcine epidemic diarrhea virus，PEDV）的遗传变异情况，本研究设计合成1对引物，应用RT-PCR方法扩增S1基因的主要中和表位区序列，并对4株PEDV分离株S1基因中和表位区进行遗传进化和B细胞抗原表位分析。结果显示，4株分离株位于同一进化分支G2上，其中湖南株和河南株与JXGZ2013、GDZQ2012、GDZQ2014株亲缘关系最近，同源性高达98.3%~98.7%；上海株与BJ-2011株、LZW分离株核苷酸同源性高达98.7%左右；福建株与2013年美国株、日本株及中国台湾变异株亲缘关系较近，核苷酸同源性高达99.0%~99.5%；B细胞线性抗原分析显示，与疫苗株相比，4株流行株在265－278位氨基酸处抗原表位明显增强。提示近年来PEDV呈现快速变异和进化趋势，抗原表位的变化可能是影响PEDV流行株感染性的主要原因。

Bioinformatics Analysis on S1 Gene of Four Porcine Epidemic Diarrhea Virus Strains

To analyse the genetic variation of porcine epidemic diarrhea virus（PEDV),one pair of primers was designed and RT-PCR was used to amplify the S1 gene epitope sequences of 4 PEDV field strains.Phylogenetic analysis showed that 4 strains were closely related to each other and belonged to the second group,and the Hunan and Henan isolates had a close relationship with JXGZ2013,GDZQ2012,GDZQ2014 strains,with the nucleotide homologies at 98.3% to 98.7%;Shanghai strain had a closed relationship with BJ-2011 strain and LZW isolates,with the higher homology at about 98.7%;Fujian isolates had a close relationship with strain of American in 2013,Japanese and Taiwan variation of China with the nucleotide homology at 99.0% to 99.5%;These results showed that a rapid variation and evolution of PEDV strains occurred in recent years,and linear B-cell epitope analysis showed that the threshold values at site 265 to 278 amino acid of 4 filed strains were higher than that of vaccine strains.The epitope differences indicated a possible of infectious that cause of patterns of epidemiology of PEDV.