Abstract: Objective]To study porcine reproductive and respiratory syndrome virus (PRRSV)genetic variation to monitor the prevalence of PRRSV in Xinjiang and provide assistance to PRRSV serology.[Method]We used RT-PCR method for the separation of 18 PRRSV ORF7 gene which was amplified,cloned and se-quenced to analyze the ORF7 gene variation[Results]The 18 PRRSV ORF7 sequence mutation type belonged to North America type.They had different genetic strain relations with the international standards and national standards strains.XJzx 4 and XJzx 1 had a closer genetic relationship with the international standard strains 01NP1.2,PA8,VR-2332 and LMY.Except XJzx1,XJzx14,the rest strains had close relationships with the mainland strains BJsy06,GD,HB-1sh 2002,HuN,JXA1,LN,NX06 and SX2009,so it could be inferred that they evolved from the strains in mainland China.[Conclusion]It is hypothesized that local pop PRRSV strains are derived from different regions.We have not detected PRRSV ORF7 gene deletion mutation in Xin-jiang.

摘要： 【目的】研究2014年新疆地区猪繁殖与呼吸综合征病毒（PRRSV）遗传变异情况，监测PRRSV在新疆流行情况，为新疆的PRRSV血清学检测提供帮助。【方法】采用RT－PCR方法对分离自新疆地区的PRRS疑似病料进行ORF7基因扩增和测序，分析PRRSV ORF7基因变异情况。【结果】检测到18株PRRSV毒株具有ORF7碱基突变，均属北美洲型，与国外的参考毒株和国内的参考毒株有着不同的亲缘关系。其中，XJzx4、XJzx12与国外的参考毒株01NP1.2、PA8、VR－2332、LMY亲缘关系较近。除XJzx1、XJzx14外，其余毒株与内地毒株BJsy06、GD、HB－1 sh2002、HuN、JXA1、LN、NX06、SX2009亲缘关系较近，推断由内地毒株演化而来。【结论】新疆本地流行猪繁殖与呼吸综合征毒株是来自国内外不同地区毒株，ORF7基因在新疆具有不同的遗传变异类型。没有检测到新疆猪繁殖与呼吸综合征病毒ORF7基因有缺失型突变。