Cloning and Sequence Analysis of VP1 Gene of Duck Hepatitis A

In order to investigate the variation of Duck hepatitis virus(DHV), a total of 12 DHV VP1 genes from different regions of Guangdong province in China were amplified, cloned and sequenced. The results showed that the lengths of all VP1 sequences were 714 bp, encoding 238 amino acids. Homology analysis revealed that the VP1 genes of 12 isolates shared91.7%-95.8% nucleotide identity and 94.5%-98.3% amino acids identity with the reference strain of DHV from Gen Bank.Nucleotide sequence homology of VP1 gene among the 12 DHV isolates varied from 99.2% to 100%, while amino acid sequence homology varied from 97.9% to 100%. The phylogenetic analysis revealed that all the 12 isolates were DHV-Ⅰ,with no In Del, but having point mutations. All 12 isolates had a close genetic relationship with a few genetic differences.