猪圆环病毒1型ORF2基因的克隆与序列分析

参照Genbank上公开发表的PCV1全基因序列设计引物，以质粒pSK-PCV为模板扩增出PCV1-ORF2基因，插入pMD18-T载体，对筛选出的阳性质粒进行测序，将测序结果同Genbank上发表的PCV1基因序列相比较，同源性达97％，再与Genbank上发表的PCV2的ORF2基因序列相比较发现PCV1-ORF2和PCV2-ORF2的差异表现在两者在核苷酸序列的2个部位互相存在基因缺失现象。将推导出的PCV1-ORF2的氨基酸序列同PCV2-ORF2进行比较，发现二者在几个功能区相当保守，尤其是N-末端的核定位序列、N-糖基化位点以及酪氨酸磷酸化位点。

Cloning and Sequencing Analysis of Porcine Circovirus 1ORF2 Gene

In order to amplify ORF2 gene of Porcine Circovirus I,a pair of primers was designed according to the Genbank sequence.The ORF2 gene was obtained by polymerase chain reaction(PCR) and!the template was the plassmid SK-PCV1 which was established by our laboratory.Then the gene was cloned into pMD18-T vector and identified by BamHI and IindIII digestion.The nucleotide sequence of PCV1-ORF2 gene was compared with the counterpart sequence of PCV1-ORF2(Accession No.AF071879) and PCV2-ORF2(Accession No.AF027217).The nucleotide homology of ORF2 between two PCV1 reaches 97%;when PCV1-ORF2 was compared with PCV2-ORF2,two regions were found lack in each. When it was compared with the animo acid of PCV2-ORF2, several conserved founctional domains were discovered,including potential N-liked glycosylation sequence, nuclear localization sequence and tyrosine phosphorylation sites.