Abstract: Duck circovirus (DuCV), a potential immunosuppressive virus in ducks. To generate the infectious genomic DNA of duck circovirus with a genetic marker, the full-length genome of the virus was amplified using PCR method. A EcoR Ⅰ restriction enzyme site was inserted into the clone as a genetic marker by site-directed mutagenesis. T4 ligase was used to cyclized the DuCV genome by phosphorylation at the 5′ terminal, in order to construct an infectious molecular clone. The viral genome could be differentiated from the wild-type parent by gene fragment sequence analyzed and EcoR Ⅰ restriction digestion. The results indicated that the infectious molecular genomic DNA of duck circovirus with a genetic marker were constructed. This study layed foundation to on pathogenesis, vaccination, molecular diagnosis and development of vaccine candidates of DuCV.

Key words: duck circovirus; genetic marker; the infectious genomic