辽宁省PRRSV LN/0901株ORF5基因遗传变异分析及其抗原位点预测

Genetic variation analysis of ORF5 gene of Liaoning LN/0901 strain PRRSV and prediction of its antigenic sites

根据已发表的PRRSVORF5基因序列设计引物,经RT-PCR对辽宁省PRRSV LN/0901株ORF5基因片段进行扩增、克隆及测序,结果得到长度为739bp的ORF5基因完整序列,与已知代表毒株进行核苷酸及其编码氨基酸同源性比对和系统进化树分析,LN/0901ORF5基因序列与VR-2332株同源性达到88.6%,而与LV株,则相差甚远,仅为61.7%,表明PRRSV LN/0901病毒株为美洲型,与CBB-1-F3T、GD2007、JXA1、BJ0708等毒株同源性高达98.7%～99.5%,表明该病毒与2006年以来国内的多数流行变异株遗传关系相近。通过对PRRSV LN/0901ORF5进行氨基酸疏水性及其编码蛋白跨膜区预测分析,表明该毒株ORF5具有多个抗原优势位点,与国内其他毒株既有共同位点又有区别位点,可以做为辽宁地区开发研制PRRS基因工程疫苗的重要蛋白基因。

According to published PRRSV ORF5 gene sequcences,the ORF5 gene fragments of Lia- oning Province PRRSV LN/0901 strain was cloned by RT-PCR amplification and sequencing result showed that the 739 bp product contains the complete sequence of ORF5 gene. The nucleotides and their encoded amino acid homology and phylogenetic analysis were carried out by referencing other known representatives of PRRSV strains. Results showed that the sequence of LN/0901 ORF5 gene shared the homology of 88.6% with the VR-2332 strains separately,but far from LV strain with only 61.7% ,indicating that PRRSV LN/0901 strain is the type of the Americas. As high as 98.7 % to 99.5 % homology with the CBB-1-F3T, GD2007 ,JXA1 and BJ0708 strain,indicating that the virus is similar to the majority of the epidemic mutant genetic relationship in the country since 2006. The analysis of amino acid hydrophobicity and encoded protein transmembrane region pre- diction showed that there were dominant and multiple antigens within the strain LN/0901 ORF5 gene,which are partly same with other strains of common sites and different sites. This suggested that the development of a specific PRRS genetically engineered vaccine with Liaoning region be- comes expectable.