Rolling-circle Amplification and Sequence Analysis of PCV2 Genomes of Xinjiang Strains
猪圆环病毒2型新疆株全基因组的滚环扩增与序列分析

Rolling-circle amplification (RCA) is an isothermal DNA amplification assay in vitro, which has good specificity and sensitivity and has been extensively applied to microbiological investigations. In this study, five diseased swine samples from certain region of Xinjiang were first detected by differential PCR for porcine circovirus type 2 (PCV2), and then RCA was utilized for amplification of the full-length genomic DNA of two positive samples. Verification with Sac II resticition enzymatic mapping showed that PCV2 specific genome-size bands appeared on agarose gel. The targeted bands were purified and cloned. With the aid of sequencing, the genomes of two viral strains were obtained and proved to be 1768 bp in length. Moreover, the phylogenetic analysis indicated that they were divided into two different genotypes (PCV2a and PCV2e).