猪流行性腹泻病毒ORF3和M基因的克隆与序列分析

为了解福建省猪流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)毒株ORF3和M基因变异情况,本研究从4个不同规模猪场发生仔猪“顽固性腹泻”疾病的病料中扩增到4株PEDV的ORF3和M基因,并进行了序列分析.结果表明:4株PEDV ORF3基因均含有675个碱基,编码224个氨基酸,与GenBank中登录的代表性PEDV核苷酸的同源性为89.7％～100.0％,氨基酸的同源性为94.7％～99.6％,其中FJPT毒株核苷酸的同源性与CV777 truncated毒株最低,仅为89.7％,FJNP毒株核苷酸的同源性与中国北方流行的CH ZKFG 11毒株最高,达100.0％.M基因含有681个碱基,编码226个氨基酸,与GenBank中登录的代表性PEDV核苷酸的同源性为94.8％～100.0％,氨基酸的同源性为94.8％～99.6％,其中FJPT毒株核苷酸的同源性与日本D89752毒株最低,仅为94.8％,FJNP毒株核苷酸的同源性与韩国CPF193、泰国毒株最高,达100.0％.4株PEDV毒株均与国内外流行强毒株的亲缘关系较近,与attenuate DR13弱毒株的亲缘关系较远.

CLONING AND SEQUENCE ANALYSIS OF ORF3 AND M GENE OF PORCINE EPIDEMIC DIARRHEA VIRUS

The sequences of four Porcine epidemic diarrhea viruses(PEDVs) were amplified from clinical samples on four pig farms with refractory diarrhea in Fujian.The ORF3 and M gene of these PEDVs were sequenced and compared with those deposited in GenBank.The ORF3 consisted of 675 nucleotides,encoding a 224-amino acid protein.These four PDEV strains shared 94.7%-99.6% amino acid identities with the PEDV strains in GenBank.The FJPT strain shared the lowest nucleotide homology at 89.7% with CV777 truncated strain while FJNP strain shared the highest nucleotide homology at 100.0% to CH ZKFG 11.The M gene consisted of 681 nucleotides,encoding a 226-amino acid protein.The M gene of these four PDEV strains had 94.8%-99.6% amino acid homology with the PEDV strains in GenBank.The FJPT strain shared the lowest nucleotide homology at 94.8% with D89752 strain while FJNP strain had the highest nucleotide homology at 100.0% with CPF193.Phylogenetic analysis indicated that the four PEDV strains were close to velogenic strain and distant with the attenuated DR13 strain.