猪圆环病毒2型甘肃株全基因组克隆及序列分析

Cloning and Sequence Analysis of the Complete Genome of Porcine Circovirus Type 2 Gansu Isolate

参照GenBank中登录的猪圆环病毒2型(PCV-2)全基因组序列,设计合成了两对特异性引物,从甘肃白银疑似断奶仔猪多系统衰竭综合征(PMWS)病料中提取病毒DNA,分步扩增全基因组。回收PCR产物,将其插入pGEM-TEasy载体,构建了重组质粒pGEM-PCV-2,转化后筛选、提取阳性重组质粒进行测序。结果表明,克隆到的PCV-2全基因组长度为1767bp。应用DNAStar序列分析软件,对所测PCV-2序列与GenBank中登录的包括甘肃在内的国内外PCV毒株进行同源性分析。结果显示,克隆的PCV-2与英国株(UK-EU656143)遗传关系最近,其核苷酸和推导的氨基酸序列同源性高达96.2%和91.0%,与已报道的2株甘肃毒株(GS03-EU547458,GSLZ-FJ447482)遗传关系较远,可能是流行于甘肃白银的一个变异毒株(GSBY)。

Two pairs of primers were designied and synthesized according to the full length genome of PCV2 in GenBank. Virus DNA was extracted from samples of suspected postweaning multisystemic wasting syndrome（PMWS） pig in Baiyin, Gansu province, and the full length genome of PCV-2 was cloned into pGEM-T easy vector, recombinant vector pGEM PCV-2 was constructed and then sequenced. Sequence analysis with DNA Star software showed that the genome of PCV-2 Gansu Baiyin isolate（GSBY） is 1 767 bp, the results of homology comparison of the full length genome among isolates published in GenBank indicated that GSBY isolate displayed high nucleotide and amino acid identities with England （UKEU656143） isolate （ 96.2% nucleotide identity and 91.0% amino acid identity）, but was different from other two Gansu epidemic isolates （GS03-EU547458,GSLZ-FJ447482）. So GSBY isolate in this test may be a variant isolate prevalent in Baiyin,Gansu.