【摘要】 前期我们实验室分离鉴定了一株nsP2蛋白缺失49个氨基酸(aa)的猪繁殖与呼吸综合征病毒(PRRSV)GXNN1396株。为了进一步对该毒株全基因组序列特性进行分析,将GXNN1396株病毒在Marc-145细胞上传至第3代,收集细胞上清,抽提该病毒RNA。用RT-PCR检测方法对GXNN1396基因组进行分段扩增、克隆、序列比较和遗传进化分析。结果表明,GXNN1 396全长15 263核苷酸(nt),不包括5′帽子结构和3′Poly A尾。其中,5′非翻译区(5′UTR)长为189nt,3′UTR长151nt,ORF1a、ORF1b、ORF2、ORF3、ORF4、ORF5、ORF6、ORF7分别为7 422、4 382、771、765、537、603、525nt和372nt。与国内外的PRRSV毒株核苷酸序列的同源性进行了比较显示,GXNN1396与欧洲经典毒株LV和VR2332株的同源性分别为61%和88.8%,与TJ、JXwn06、JXA1在全基因上的同源性高达97.2%~97.3%,说明GXNN1396株是一株典型的美洲型PRRSV毒株。遗传进化分析表明美洲型PRRSV主要分为3个亚群,GXNN1396与高致病性PRRSV毒株属于同一分支。更多还原

【Abstract】 Previously,we isolated and identified a novel PRRSV strain(GXNN1396)with 49 amino acids deletion in nsP2.In this study,to further characterize the full length genome of GXNN1396,Marc-145 cells were inoculated with GXNN1396.The supernatant of infected cells was collected and used for virus RNA extraction.A set of primers were designed for RT-PCR to amplify the full-length genome of GXNN1396.The nucleotide sequence of GXNN1396 was compared with the reference PRRSV strains retrieved from GenBank.The phylogenic tree of GXNN1396 and the reference strains was constructed based on the full-length genome.The results showed that the complete genome of GXNN1396 consists 15 263 nt,excluding the 5′cap and 3′poly A tail. The 5′ UTR has 189 nt and 3′ UTR has 151 nt. ORF1 a, ORF1 b, ORF2,ORF 3,ORF4,ORF5,ORF6andORF7contain7422,4382,771,765,537,603,525and372 nucleotides,respectively.The complete genome of GXNN1396 shares 88.8% identity with VR2332,and shares 97.2%-97.3%identity with highly pathogenic PRRSV strains TJ,JXwn06,JXA1,but only has 61%identity with type 1PRRSV stain LV,suggesting GXNN1396 belongs to type 2PRRSV.The phylogenic analysis based on the full length genome revealed that PRRSV strains were classified into 3clades and GXNN1396 was distributed with highly pathogenic PRRSV strains TJ,JXwn06,JXA1.更多还原