中文摘要：

通过PCR扩增出猪圆环病毒2（PCV-2）3个亚群（1A、1B、1C）毒株的全基因组DNA序列,并分别克隆入pMD-18T载体,获得含有PCV-2全基因组的3个重组质粒,分别命名为RP8（1A）、P0（1B）和P4-1（1C）。将3个重组质粒分别用SacⅡ切出l 767 bp的PCV-2全基因组,并在体外分别用T4连接酶连接而环化。用脂质体将3种自身环化的基因组转染无PCV-1污染的PK-15细胞,并按常规病毒培养方法分别传代,第5代细胞培养物分别用间接免疫荧光试验（IFA）及PCR方法检测转染的细胞,检测结果均为阳性,说明已获得PCV-2共3个亚群1A、1B、1C的感染性克隆。用1A、1B、1C感染性克隆的第5代细胞培养物分别接种小鼠,可在接种小鼠的血液中分别检测到相应PCV-2亚型的基因组DNA,表明本试验构建的自身环化的1A、1B、1C亚型的PCV-2的全基因组DNA在体内、体外均具有感染性。

英文摘要：

The complete genome of three subgroups（1A,1B,1C） of porcine circovirus 2（PCV-2）was amplified by polymerase chain reaction（PCR） and cloned directly into plasmid pMD-18T,and recombinant plasmid carrying the complete genome was constructed,designated RP8（1A）,P0（1B）,P4-1（1C） respectively.The three entire genomes of PCV-2 were purified and recycled from recombinant pMD-18T with the digestion of SacⅡ enzyme and then circular genomic DNA were generated by self-ligating with T4 DNA ligase in vitro,resulting in three circular virus genome.The PCV1-free PK-15 cells were transfected with the PCV-2 circular genome using lipofectin reagent.At the fifth passages,PCV-2 virus and specific antigens could be detected by PCR and indirect immunofluorescent assay（IFA）.Mice were inoculated with the cell cultures which were passed 5 times,the blood samples were collected 5 d after inoculation,the PCV-2 genomes were confirmed by PCR.The results indicate that the cloned circular PCV-2 genomic DNA is infectious both in vitro and in vivo,which will provide good foundation for further study of the relationship between different genotype PCV-2 strains and their virulence.