Cloning of DHBV Complete Genome from Guangdong Brown Ducks and Finding of a New ORF

3 samples of Duck hepatitis B virus (DHBV) positive serum from Guangdong brown ducks were chosen to be experimental samples. One pair of primers named Q1 and Q2 were designed to amplify the DHBV complete genome. Following the DHBV complete genomes from the 3 DHBV positive serum samples were amplified and cloned, these DHBV complete genomes were sequenced and then analyzed through related software and related molecular biology methods. The results showed that all the 5 complete genomes from Guangdong brown ducks were 3027 nucleotides long. After submitting to the GenBank, the accession Number were attained as: AY433937, AY521226, AY521227(from DHBV positive serum Number 1.);AY392760, AY536371(from DHBV positive serum Number 2 and 3 respectively). One single nucleotide mutation was occurred in the PreS/S ORF of AY521227. A new ORF was found in the upper reaches of PreC/C ORF and named as HORF temporarily. The HORF also exists in the other 8 DHBV complete genomes from Genbank. Phylogenetic analyze indicated that