我国登革 4型病毒 B5株基因组全序列的测定及分析(英文)

Determination and Analysis of the Complete Genomic Sequence of the Dengue Type 4 Virus B5 Strain Isolated in China

对我国登革 4型病毒 B5株 (D4- B5)基因组进行全序列测定及分析 ,为研究病毒基因组结构与功能的关系及研制新型登革疫苗奠定基础 .根据登革 4型病毒 81 4669株的序列设计特异引物 ,通过 RT- PCR扩增出 D4- B5株不同长度的片段 ,分别克隆到 p GEM- T载体 ,将挑取的阳性克隆进行 PCR、酶切鉴定及序列测定 .结果显示 ,D4- B5株的基因组全长 1 0 665nt,5′和 3′非编码区分别为 1 0 1 nt和 40 3nt,中间一个长 1 0 1 61 nt的开放读码框架 ,编码 3387个氨基酸 .与 D4- 81 4669株比较 ,两者核苷酸序列同源性为 93.0 8% ,氨基酸序列同源性为 96.58% .D4- B5株的基因组全序列与 D4- 81 4669株类似 ,但也有较大差异 .同源进化分析表明 ,D4- B5株的基因型为 型 ,与登革 4型病毒菲律宾分离株亲缘关系较近 .这是首次报道的我国登革 4型病毒分离株基因组全序列 ,对研究病毒基因组结构与功能的关系 ,探讨我国毒株的地理来源及研制适合我国人群的新型登革疫苗具有一定的意义 .

The complete genome of dengue type 4 virus B5 (D4 B5) strain was sequenced to provide a direct information about the relationship between the viral genomic structures and their biological functions,and to develop new dengue vaccines.Specific primers were designed according to the sequence of the dengue type 4 virus 814669 strain.Specific gene fragments of D4 B5 strain were amplified by RT PCR and cloned into pGEM T vector.Positive clones were screened by PCR and determined by specific endonuclease digestion.The sequences of the inserted fragments were determined by PRISM TM ABI 377 automated sequencer.The results show that the complete genome of D4 B5 strain is 10 665 nt in length and contains a long single ORF of 10 161 nt,which encodes a precursor polyprotein of 3387 amino acids and is flanked by a 101 nt 5′ NCR and a 403 nt 3 NCR.Compared with D4 814 669 strain,D4 B5 strain shows a nucleotide sequence identity of 93.08% and an amino acid sequence identity of 96.58%.Although with notable differences compared with D4 814 669 strain,D4 B5 strain has the common genome structure of dengue type 4 virus.Homology analysis among 20 dengue type 4 virus isolates reveals that D4 B5 strain belongs to genotype Ⅰ and is most similar to D4 12123 strain isolated in Philippines in 1984.This is the first report on the complete genome sequence of dengue type 4 virus strain isolated in China,which is helpful to understand the relationship between viral genome structures and biological functions,the phylogeny of Chinese isolates and the development of new dengue vaccines.