探讨HCV准种在NS2区的基因结构特征及变异状况。利用逆转录一巢式PcR从1份Hcv慢性携带者的阳性 血清及1份丙肝患者的血清中获得HCV NS2全长eDNA，将其克隆于T载体，各随机挑取5个阳性克隆进行序列测 定。结果显示克隆到HCV．NS2全长基因，所测克隆在核苷酸水平和氪基酸水平互不相同。该慢性携带者HCV NS2 区序列以完整读码框架(0RF)为主，一个于HCV多聚蛋白第8 位氪基酸的位置出现终止信号，而该丙型肝炎患者 以NS2 N端发现终止信号的序列为主，其中三个于第835位氪基酸的位置出现终止信号，一个于第887位氪基酸的 位置出现终止信号，仅一个克隆的序列为完整ORF。对ORF竞整的序列进行比较，发现丙型肝炎患者氮基酸变异主要集中于N端，蛋白二级结构模拟显示丙肝患者NS2与慢性携带者的优势二级结构类似。研究表明从我们选择 的两倒感染者的HCV 盟序列看，不同临床类型的Hcv病人体内的HCV准种在N啦区存在差异，这种差异可能与 病毒存在于机体的状态有一定的一致性。

To explore the genetic variation of nonstmetural(NS)2 region and its gene structural characteristics in hepatitis C vims quasispecies，NS2 genes ofHCV from a HCV as)~nptomatie~[Tier and apatien twith ab． nomud ALT level tteile amphfied by RT-nested-PCR respectively and cloned into T Yector．5 positive clones form each of them were selected~ domly for sequencing．Eve~-clone WaS unique in nuclectide sequence and amino acid sequence．A 0Bt all the NS2 gene clones from the asymptomatic carrier had complete ORF ex。ept OIle done had a stop codon at 835aain HCV polypmtein．Butwhenit ean3~tothepatientwith abnorm al ALT level，3 clones of them had stop cadom．at 835aa and 1 clone had a stop ced on at 887aa in polypretein． 0nly 1 clone had complete ORF．Comparing this ORF with the s~ ence of the as)~lptomatic carrier，most of the~aino acid changes were confined to the N-termlnai．Simulating the so。ondarv strucRu~s of Ns2 proteins with intact openreadingframe demomUated thatthe structure ofthe HCV patientwith abnormalA levelwas similart0 the dominant structure ofthe asymptomatic carrier．It could beseenfrom thetwopatientswith HCV infection thatHepatitis C viral quasispeciesin NS2 r 0nhadan obvious diversity between HCv as)~lptoraatic p~riier and HCV patient with abnomaal A leve1．The diversity suggested that the stale of HCV qua~species in NS2 region WSSlikelyto correlatewith the progression ofliver diseas