A study on the mutation of P gene region including YMDD motif in hepatitis B virus / 中华肝脏病杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the primary structure and heterogenenity of P gene region including YMDD motif in hepatitis B virus.</p><p><b>METHODS</b>From serum samples collected from 4 patients who had never been treated with anti-viral drugs, DNA fragments of 1057bp long of P gene were amplified and cloned into pUC19. Twenty positive clones were chosen randomly from each sample. The YMDD motif mutation was detected by mismatched PCR-RFLP. Finally last ten positive clones of two samples were sequenced.</p><p><b>RESULTS</b>Nucleotide mutation rates among clones of Sample 1 and 2 were 0.3% - 1.1%, 0.4% - 1.7%, respectively. Among 80 clones, the variations from YMDD to YMGD were revealed in two clones.</p><p><b>CONCLUSION</b>There are HBV quasispecies in the P gene region including YMDD motif of hepatitis B virus and a novel mutation of YMDD motif in the sera of patients without being therapied by anti-viral drugs.</p>