广东地区GBV-C/HGV5′NCR区序列变异的研究

Study on the GBV-C/HGV heterogeneity in guangdong

目的 了解广东地区GBV -C/HGV 5′NCR区的序列变异情况。方法 以GBV -C和HGV的 5′NCR区完全同源的序列设计合成引物用于套式RT -PCR。从广东地区的 10例GBV -C/HGV感染者血中扩增了 10个序列 ,分别克隆至pUC19或pT -Adv载体。以 3 5S标记的双脱氧链末端终止法对这 10个序列分别进行正反两个方向的序列测定。结果 10株序列相互间同源性最大为 10 0 % ,最小为 84 4%。与Genbank所载 3个标准株的相应序列比较 ,其同源性最大为89 4% ,最小为 83 9%。与国内周育森报道的相应序列比较 ,两者之间的同源性最大为 96 1% ,最小为 85 0 %。比较还发现 ,这 10株序列的起始处有一段 3 8nt的区域与上述标准序列相比变异比较大 ,其与标准序列的同源性最高只有 79 0 % ,最低为 60 5 %。其中 9株相互间的这一 3 8nt序列的同源性则高达 92 %～ 10 0 %。结论 广东地区流行的庚型肝炎病毒大多带有HGV的特殊点。少数为GBV

Objective To study the GBV-C/HGV heterogeneity in Guangdong. Methods The completely homologous sequences of the 5′NCR region between HGV and GBV-C were used to design and synthesize two pairs of primers, which were applied in a RT-PCR test to amplify 10 sequences in sera from 10 patients with GBV-C/HGV infection. The PCR products were cloned into pUC19 vectors or PT-Adv vectors. By using the method of dideoxy-mediated chain-termination, the HGV sequences inserted in the pUC19 and PT-Adv vectors were sequenced. Results The highest degree of nucleotide homology of these 10 HGV isolates is 100% and the lowest is 84.4%. When compared to the three standard sequences of U44402, U45966 and U36380, the highest and lowest homology is 89.4% and 83.9%. When compared to the sequence reported by Zhou Yushen, The highest and lowest homology is 96 1% and 85 0%. Furthermore, a 38nt highly mutant region was found at the beginning of these 10 HGV sequences, with the highest and lowest homology of 79.0% and 60 5% compared to three standard sequences.In the 38nt region, 9 of 10 isolated strains have an homology of 92%～100%. Conclusion 9 isolate strains carry the characteristic of “Guangdong subtype HGV”, the left one strain seems to be like GBV-C.