猪流行性腹泻病毒S、N和ORF3基因的遗传变异分析

Genetic Variation Analysis of S,Nand ORF3 Genes of Porcine Epidemic Diarrhea Virus

为探明2012—2013年在福建省流行猪流行性腹泻病毒（PEDV）结构蛋白的遗传变异情况,对7株PEDV流行毒株的S、N及ORF3基因进行克隆、测序及分析。结果表明:7株PEDV S基因之间的核苷酸相似性为98.6%99.4%,与attenuated DR13弱毒株和CV777标准株的相似性分别为93.7%94.1%和93.8%94.1%;同CV777标准株比较,存在64个氨基酸突变,其中有3个氨基酸较以往国内外流行毒株的变异不一样,为新变异氨基酸,氨基酸的插入和缺失与2008年泰国NPPED20082株相似;7株PEDV毒株的N基因和ORF3基因之间核苷酸的相似性分别为96.5%99.7%和99.7%100%,与CV777标准株的相似性分别为96.6%98.0%和96.6%96.9%。遗传进化树表明:7株PEDV毒株的S基因和ORF3基因与泰国流行毒株的亲缘关系较近,N基因与CV777标准株亲缘关系较近。7株PEDV毒株的S基因和ORF3基因变异程度较大,可能源于泰国及韩国的变异株。

To investigate the variation in structure protein of porcine epidemic diarrhea virus(PEDV),S,N and ORF3 genes of 7PEDV strains were cloned and sequenced from different farms in Fujian in 2012-2013.The results indicated that the nucleotide sequences of Sgene shared98.6%-99.4%identity within them,shared 93.7%-94.1%identity with attenuated DR13 strain,shared 93.8%-94.1%identity with CV777 strain.Compared with CV777 strain,there were 64 variant amino acids,and 3amino acids different from other prevalent strains at home and abroad,and might be new variations,and 5amino acids insertion,and 2amino acids deletion.The amino acids insertion and deletion were similar to NPPED2008_2strain isolated in Thailand.The nucleotide sequence of N and ORF3 genes shared 96.5%-99.7% and 99.7%-100% identity within them,and shared 96.6%-98.0% and 96.6%-96.9% identity with CV777 strain,respectively.Phylogenetic analysis indicated that Sand ORF3 genes of the 7PEDV strains had a closer relationship with the Thailand strain,and N gene had a closer relationship with the CV777 strain.The results showed that Sand ORF3 genes of the 7PEDV strains varied greatly,and these strains might origin from Thailand and Korea strains.