3株临床分离的猪流行性腹泻病毒S基因克隆及序列分析

Cloning and Sequence Analysis of S Gene of Three Porcine Epidemic Diarrhea Viruses Isolated from Clinical Samples

对临床分离鉴定的3株猪流行性腹泻病毒(PEDV)的S基因进行克隆及序列分析,对丰富我国PEDV的遗传衍化特征具有重要意义。S基因序列分析发现,JX18毒株与CV777亲缘关系较近,核苷酸同源性为99.71%,氨基酸同源性95.7%,属于G1-b进化分支。JX18毒株与CV777经典毒株S蛋白氨基酸序列相比较,不存在氨基酸的插入或缺失,在中和表位区及已鉴定抗原表位区仅有一处氨基酸突变。SD18、JingTai18与PEDV CV777亲缘关系较远,核苷酸同源性分别为93.64%和92.64%,S蛋白氨基酸序列同源性分别为93%和93.5%。SD18和JingTai18位于G2-b进化分支。SD18与JingTai18株与CV777经典毒株相比,S蛋白氨基酸序列中存在插入缺失及多位点的氨基酸突变。研究结果为进一步了解我国PEDV流行及变异情况提供了数据支持。

In this study,the cloning and sequence analysis of the S gene of three porcine epidemic diarrhea viruses(PEDV)identified in the clinical samples were of great significance for enriching the genetic evolution characteristics of PEDV in China.Sequence analysis of S gene revealed that the JX18 strain is closely related to CV777,with nucleotide homology of 99.71%and amino acid homology of 95.7%,belonging to the G1-b evolutionary branch.Compared with the protein sequence of the CV777 classic strain,the JX18 strain does not have an amino acid insertion or deletion,and there is only one amino acid mutation at the neutralizing antigentic epitope and the epitope.SD18,JingTai18 are far away from PEDV CV777,nucleotide homologies are 93.64%and 92.64%,respectively,and protein sequence homologies are 93%and 93.5%,respectively.SD18 and JingTai18 are located in the G2-b evolutionary branch.Compared with the CV777 classic strain,SD18 and JingTai18 strains have insertions deletions and multiple amino acid mutations in the protein sequences.The research results provided data support for further understanding the prevalence and variation of PEDV in China.