江苏地区6株猪圆环病毒2全基因的克隆与分析

Sequencing of the Complete Genome of Six Isolates of Porcine Circovirus Type 2 from Jiangsu Province

根据已发表的猪圆环病毒2基因序列设计1对PCR引物，用PCR方法从6株PCV2江苏分离株（YZ60615．YZ60721，YZ70717，TZ60607，TZ60804、YC60711）中扩增出相应的全基因组DNA片段。按常规方法克隆，获得6个含有相应片段的重组质粒。序列测定结果表明，6株病毒的基因组大小均为1767nt，与GenBank中已发表序列同源性为94．6％～100．0％。遗传进化分析表明，这6株江苏地区的病毒与浙江株（AY678532，AY691169，AY510375）、福建株（DQ180393）、江苏株（1）QL04422）亲缘关系较近，与多数中国分离株亲缘关系较近并形成较大的一簇，而与美国株（AF264041）、加拿大株（AF086836）遗传关系较远。

A pair of primers was designed and synthesized according to the published genomic sequence of porcine circovirus type 2 （ PCV2 ）, and the complete genomes were amplified from six different PCV2 isolates as TZ60607, TZ60804, YC60711, YZ60615, YZ60721 and YZ70717. All the PCR products were cloned into pGEM-T easy vector re- spectively, and six recombinant plasmids as pYZ60615, pYZ60721, pTZ60607, pTZ60804, pYZ70717 and pYC60711 were obtained. The recombinant plasmids sequences were analyzed and compared with the published sequences. The data showed that the six isolates＇ genome were all 1 767 nt ,belonging to PCV2 group with 94. 6% to 100. 0% identity at nucleotide acid level. In addition, the six isolates were all closed to most PCV strains from China, while had a distant evolutionary relation to the strains from USA （AF264041） and Canada （AF086836）.