中国上海丁型肝炎病毒部分基因的克隆与序列分析

Molecular cloning and preliminary identification of a new subgroup strain of genotypeⅠhepatitis delta virus isolated from Shanghai,China

从我国上海无症状的乙型肝炎病毒表面抗原(HBsAg)携带者混合血清中提取 RNA,通过逆转录聚合酶链反应获得丁型肝炎病毒(HDV)的比约370个碱基对的 cDNA 片段。将其克隆测序并与已知的 HDV 各基因型代表株序列比较,结果表明,它与意大利株的同源性较高(98.1%),与台湾株(Ⅰa型)及美国-1(Ⅰb型)的同源性相近(91.0%,92.0%),与口本-1株(Ⅱ型)及秘鲁株(Ⅲ型)的同源性为79.3%和72.4%,提示上海株可能是介于 HDV Ⅰa与Ⅰb亚型间的中间(或过渡)亚型。

To expand our understanding of genetics of HDV infection in normal population in Shanghai, China,we collected serum samples from 100 adults who were hepatitis B surface antigen(HBsAg)asymtomatic car- riers.The serum samples were mixed and RNA was prepared from samples equivalent to 5ul of serum.The RNA obtained was reversetranscribed and amplified by polymerase chain reaction(PCR).The fragment corresponding to positions 935-1308[numbering according to Wang et al 1986,Nature 323:508] was obtained and cloned.Se- quencing was performed for three clones by the dideoxy chain-termination method.Comparion of the nucleic acid sequences of Shanghai strains(from asymptomatic carriers)with some known sequences of HDV representative strains revealed that the Shanghai HDV strains is most closely related to Italy strain(after passage in chimpanzees and woodchucks)with 98.1% homology,and shared similar horology with subgroup Ia and Ib representative strains (91.0% homology with Taiwan and 92.0% with US-1 respectively).Its homolgy with Japan-1 and Peru-1 strains was lower(79.3% and 72.4%,respectively).It may be a transitional(or an intermediate)subgroup between Ia and Ib of HDV genotype.The biological significance of this subgroup is to be investigated.