Determination and analysis of complete nucleotide sequence of Chinese genotype D hepatitis B virus: the first report

OBJECTIVE: To determine the complete nucleotide sequence of a Chinese hepatitis B virus (HBV) strain of genotype D. METHOD: The complete nucleotide sequence of HBV derived from a Chinese chronic asymptomatic carrier was amplified by PCR and cloned to conduct sequence analysis. Homology of the resulted nucleotide sequence with those of published HBV strains was assessed by using DNASIS, and complete sequence analysis of the phylogenetic tree of 30 genotype D HBV strains conducted by the assistance of Clustalw. RESULTS: With the complete nucleotide sequnce of 3 182 bp, this HBV strain belongs to ayw3 subtype and D genotype, with the Genebank accession number AF280817. Its complete nucleotide homology is 98.3% to 94.5% with the published sequences of genotype D HBV strains and less than 89.5% with the other HBV strains of genotype A, B, C, E, F and G published in GenBank. CONCLUSION: The evolutionary relations of the complete nucleotide sequence of this HBV strain is the closest to those of the 4 Swedish strains out of the 30 genotype D strains published in GenBank.