猪2型圆环病毒ORF1与ORF2基因和伪狂犬病毒基因的重组与表达的研究

根据GenBank发布的猪2型圆环病毒(PCV2 )序列(AY0 35 82 0 ) ,设计两对特异性引物,采用PCR方法,分别扩增了猪2型圆环病毒ORF1和ORF2基因。将ORF1和ORF2基因的PCR产物回收并酶切后,依次插入到伪狂犬病毒gE gI双缺失通用转移载体pIECMV中,构建了猪2型圆环病毒_伪狂犬病毒重组中间转移质粒pIEORF1-ORF2。采用脂质体介导法,将重组中间转移质粒pIEORF1_ORF2与伪狂犬病毒TK^- gE^- LacZ⁺ 基因组共转染IBRS_2细胞,待发生细胞病变后收集病毒液进行空斑纯化,利用检测PCV2ORF1基因和ORF2基因的PCR方法筛选重组病毒TK^- gE^- gI^- ORF1-ORF2⁺ ,用Southernblotting鉴定重组病毒,并用Westernblotting检测ORF1_ORF2融合蛋白的表达情况,在此基础上也测定了重组病毒在不同细胞上的增殖滴度。结果表明,外源基因ORF1和ORF2已成功插入到TK^- gE^- LacZ⁺ 亲本株的基因组中,并获得了表达,表达的蛋白可与PCV2阳性血清发生反应。同时发现ORF1和ORF2基因的插入不影响重组病毒的增殖特性，其毒力与亲本株相当。

Recombination and Expression of ORF1 and ORF2 Gene of Porcine Circovirus Type 2 and Gene of Pseudorabies Virus

ORF1 and ORF2 gene of porcine circovirus type 2 were cloned by PCR with the specific primers designed according to genome of PCV2 (AY035820). Following extraction and digestion, PCR products were subsequently inserted into universal transfer vector pIECMV (deleted partial gE and gI of pseudorabies virus) to generate recombinant transfer plasmid pIEORF1-ORF2. The genomic DNA of PRV TK -/gE -/LacZ + strain and pIEORF1-ORF2 were co-transfected into IBRS-2 cells with lipofectin, and recombinant virus TK -/gE -/gI -/ORF1-ORF2 + was selected by PCR with ORF1 gene and ORF2 gene primers respectively. The recombinant virus was analyzed with Southern blotting and Western blotting. The results indicated that ORF1 and ORF2 gene of PCV2 had been inserted into the genome of TK -/gE -/LacZ + strain and the expressed ORF1-ORF2 fusion protein could react with PCV2 positive sera. Result of virus titers detection showed the insertion of ORF1 and ORF2 gene did not influence propagation of recombinant virus.