PRRSV JX0708株结构蛋白基因的克隆及其生物信息学分析

根据GenBank中登录的美洲型PRRSV JXA1株基因组序列设计合成了4对引物,应用RT-PCR技术对PRRSV JX0708株结构蛋白基因进行扩增、克隆和测序,将测序结果应用Blast和DNAStar软件进行分析,并与国内外分离株进行核苷酸序列以及推导的氨基酸序列同源性比较.结果表明:PRRSV JX0708株结构蛋白基因长约3 186bp,分为ORF2、ORF3、ORF4、ORF5、ORF6和ORF7共6个基因区;与国内分离的高致病性PRRSV美洲型毒株HuN、GD、JXA1、LN和普通毒株CH-1a以及经典毒株VR-2332和疫苗毒株pMLV的核苷酸及其推导的氨基酸同源性分别为88.0%～100.0%和83.5%～100.0%;而与欧洲型经典毒株LV和Euro-1的同源性差异显著,其核苷酸和推导的氨基酸同源性分别为64.0%～69.7%和53.3%～79.9%.遗传进化分析表明,PRRSV JX0708株在基因型上属于美洲型,同时美洲型PRRSV的变异存在某种地域和时间跨度上的相关性,但每个结构蛋白基因的变异并不严格遵从这种规律,而有所差异.

Cloning and bioinformatics analysis of structural protein genes of PRRSV JX0708 strain

According to the sequence of porcine reproductive and respiratory syndrome virus(PRRSV) JXA1 strain published in GenBank,four pairs of primers were designed and synthesized to amplify the structural protein genes of PRRSV JX0708 strain by RT-PCR.The sequences were compared with other PRRSV strains by Blast and DNAStar.The results showed that the complete structural protein genes was 3 176 bp,and the open reading frame include ORF2,ORF3,ORF4,ORF5,ORF6 and ORF7.The six structural protein genes of JX0708 strain shared 88.0%~100.0% of nucleotide homology and 83.5%~100.0% of amino acid homology with North American genotype such as HuN,GD,JXA1,LN,CH-1a,VR-2332 and pMLV,respectively.However,they shared 64.0%~69.7% of nucleotide homology and 53.3%~79.9% of amino acid homology with LV and Euro-1 strain.The phylogenetic trees analysis revealed that PRRSV JX0708 was clustered within North American genotype which had the closest relationship with origin and time span,while each structural protein genes was not simply.