猪圆环病毒2型广东株全基因的克隆与序列分析

根据GenBank中发表的已知猪圆环病毒2型(Porcine Circovims-2，PCV-2)全基因序列，自行设计2对特异性引物，从2株接种疑似断乳仔猪多系统衰竭综合征(post-weaning muhisystemic wasting syndrome，PMWS)仔猪病料的PK-15细胞中提取基因组DNA，以此为模板，用PCR方法分2段扩增2个PCV-2广东株(GZ株和ZS株)的全基因序列．应用序列分析软件DNAstar，对所测2组PCV-2序列与GenBank中的国内外PCV-2毒株进行同源性比较，并绘制系统进化发生树，进行了序列分析．结果表明，2个PCV-2广东株全基因组皆为1767bp，2个毒株间全基因序列核苷酸同源性为77．0％，第一开放阅读框(ORF1)间的核苷酸同源性仅为57．7％，而第二开放阅读框(ORF2)间的核苷酸同源性却高达99．1％．ZS株和GenBank中国内外其他的PCV-2参考毒株序列的核苷酸同源性在95．7％-99．5％之间；而GZ株和其他PCV-2参考毒株序列的核苷酸同源性仅在74．2％-77．1％之间．

Cloning and sequence analysis of complete genomes of type 2 porcine circovirus isolated from Guangdong Province

Based on the complete genomic sequence of PCV-2 in GenBank, two sets of primers were designed, and genomic DNA was extracted from PK-15 cell inoculated with pathogenic materials of piglets with PMWS. Complete genomic sequences of two isolates from Guangdong Province were amplified. The two sequences were compared with that of other PCV-2 isolates in GenBank with the DNAStar software, and a phylogenetic tree of PCV-2 strains was drawn. The length of the complete genome of GZ and ZS strains was (1 767) bp; nucleotide similarity of the complete genome among two strains was 77.0%; but nucleotide similarity of ORF1 only was 57.7%, but which of ORF2 was 99.1% among two strais; nucleotide similarity of the complete genome among ZS strain and other strains were from 95.7%-99.5%, and were from 74.2%-77.1% among GZ strain and other strains.