乙型肝炎病毒C基因启动子区异质性检测初步研究

A study on the heterogeneity of core promoter region in hepatitis B virus DNA

目的 以乙型肝炎病毒 (HBV)C基因启动子 (CP)变异来探讨HBV准种的存在意义。方法 设计特异性多聚酶链反应 (PCR)引物 ,自 9例慢性HBV感染患者外周血血清中扩增HBVCP序列 ,克隆入pGEMTeasy质粒 ,随机挑选 37个克隆进行DNA测序以确定病毒的变异程度。结果 测序发现HBVCP序列是变异的高发区 ,在直接重复序列 (DR)I上游存有一缺失突变高发 (48 7% ,18/37)区 ,缺失突变与替换突变在TATA样盒TA2、TA3区发生率较高 ,而TA4极为保守。结论 CP区内有一缺失高变区 ,TA2、TA3的变异影响前C蛋白的表达 ,但该区的变异不影响前基因组RNA的转录。结果提示 。

Objective To investigate the HBV quasispecies groups in the patients with chronic HBV infection.Methods The whole core promoter(CP)region was amplified by PCR from the sera of 9 patients with chronic HBV infection,and then the PCR products were subcloned into pGEM Teasy vectors.Clones were randomly selected to be sequenced.sequences of selected clones were compared to find the difference.Results The point mutation always occurred in TATA like boxes,especially in TA2 and TA3.There was a hot region 48.6%(18/37) in basic core promoter.Conclusions The deletion mutation in TA2 and TA3 influences the expression of pre C/C protein.The conserved TA4 box guarantee the transcription of pre genome RNA in HBV life cycle.The sequencing results imply that there are HBV quasispecies groups in chronically infected patients.