Quasispecies and variations of hepatitis B virus: core promotor region as an example / 中华实验和临床病毒学杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the HBV quasispecies groups in the patients with chronic HBV infection.</p><p><b>METHODS</b>A set of specific primers was synthesized according to DNA sequence of HBV strain found in China. The whole core promoter (CP) region was amplified by PCR method from the sera of 3 patients with chronic HBV infection, and the PCR products were subcloned into pGEM Teasy vectors. The clones were randomly selected to be sequenced. Sequence comparison of the selected clones was made to find the difference.</p><p><b>RESULTS</b>By comparison, it was found that each sequence of selected clones was different. The point mutation always occurred in TATA-like boxes, especially from T to C replacement on 184 site. There is a hot region (33.3% 5/15) in basic core promoter where deletion mutation frequently happened.</p><p><b>CONCLUSIONS</b>There is a hot deletion region near DR I in CP. The replacement at 184 nt (T to C) in the third TATA-like box may influence the expression of pre-C/C protein. The sequencing results suggest that there are HBV quasispecies groups in chronically infected patients.</p>