猪圆环病毒2型10JS-2株的分离与全基因组序列分析

本试验从江苏某猪场采集猪血清,进行猪圆环病毒2型(PCV2)的检测和分离,根据GenBank中登录的PCV2全基因组序列,设计1对特异性引物,扩增PCV2全基因组,并且进行序列测定和分析。发现一株PCV2 10JS-2的基因组全长为1779 nt,在病毒复制起始区域含有11个碱基的插入。在GenBank中对含有11个碱基插入的毒株序列进行BLAST发现,有两株PCV2(AY321993和EF565360)也有11个碱基的插入,但是与10JS-2比较,插入的碱基和插入的位置不同。遗传进化分析显示10JS-2属于PCV2a基因型,AY321993和EF565360属于PCV2b基因型,因此推断10JS-2可能是由PCV2a基因型的毒株在复制起始区域发生碱基插入形成的。这是首次发现此类PCV2毒株。

Isolation and Complete Genome Sequence Analysis of Porcine Circovirus Type 2(PCV2) Strain 10JS-2 from Jiangsu Province,China

Serum sample was collected from a pig in Jiangsu province,China,and virus detection and isolation of porcine circovirus type 2(PCV2) were performed.A pair of primers was designed to amply the complete PCV2 genome according the PCV2 sequences submitted to GenBank for sequencing and analysis.A PCV2 strain 10JS-2 was isolated.The complete genomic sequence of 10JS-2 was 1779 nt in length.Remarkably,a special 11 nt insertion in the origin of viral genome replication(Ori) of 10JS-2 was observed.BLAST search on NCBI website revealed that another two PCV2 strains(AY321993 and EF565360) also had 11 nt insertion in Ori.However,the insertion sequence and the location of the insertion were different.Phylogenetic analysis revealed that 10JS-2 belong to genotype PCV2a,while AY321993 and EF565360 were classified into genotype PCV2b.So,we inferred that 10JS-2 probably derived from PCV2a strains that obtained the 11 nt insertion in Ori.This is the first report about this kind of PCV2a strain.