Abstract: The VP3 gene of duck hepatitis virus type 1 (DHV-1) was amplified by reverse transcription-polymerase chain reaction (RT-PCR), compared with the reference sequences and analyzed genetically using DNAStar software. The acquired VP3 gene was cloned into the prokaryotic expression vector pET32a(+). The resultant pET-VP3 was transformed into E.coli Rosetta(DE3) cell and induced with 1mM IPTG. The expression product was analyzed by SDS-PAGE and Western blotting. The results showed that the VP3 gene was successfully cloned with 711bp in length. Sequences analysis results indicated that the VP3 gene of DHV-1 ZJ-V strain has a higher sequence identify with the other DHV genotype A isolates ranging from 95.1% to 97.7%, a lower sequence identify with the other DHV genotype C isolates ranging from 71.3% to 72.6%, and the lowest sequence identify with the other DHV genotype B isolates ranging from 70.3% to 70.5%. the results of SDS-PAGE and Western blotting revealed that the recombinant VP3 protein with a relative molecular mass of 47ku, can be expressed in the E.coli Rosetta(DE3) cell and recognized by positive serum against DHV-I ZJ-V strain, showing good immunogenicity.

Key words: duck hepatitis virusⅠ; VP3 gene; prokaryotic expression; sequence analysis