新分离登革2型病毒福建株基因组全序列的测定

目的 对新近分离的导致1999年福建省登热流行的登革2型病毒FJ－10株进行基因组全序列测定及系统发生树分析。方法 利用RT－PCR和5′、3′RACE法扩增FJ－10株cDNA，并进行克隆测序，利用DNASTAR折Clustal方法绘制系统发生树。结果 JF－10株基因组全长10723个核苷酸，有1个单一开放读码框架（ORF，第97－10269nt），编码3391个氨基酸，5′和3′非编码区长度分别为96和454个核苷酸，通过与标准株NGC株和我国其他地区分离株DEN2－04、43、44株比较，核苷酸同源性分别为94.0%、92.8%、93.9%和93.9%，氨基酸同源性分别为97.9%、97.2%、97.7%和97.9%。以47株登革2型病毒E／NS1连接区240个核苷酸序列进行发生树分析，福建株与印度尼西亚和斯里兰卡分离株亲缘关系较近,同属第Ⅳ基因型。结论 FJ－10株基因组全序列一级结构与其他登革2型病毒类似，其基因型不同于我国其他地区分离株DEN2－04、43和44株。

Genomic sequence determination of a new dengue 2 virus Fujian strain

Objective　To determine the complete genomic sequence of a new dengue 2 virus FJ-10 strain isolated from a patient with dengue fever in Fujian province in 1999. Methods　The cDNA of FJ-10 strain was amplified by using RT-PCR and 5′/3′ RACE methods, then cloned and sequenced. The phylogenetic tree was produced by using Clustal method of DNASTAR software. Results　The complete genome of FJ-10 strain was composed of 10723 nucleotides, including a single open reading frame(ORF, 97-10269nt), encoding 3391 amino acids. The lengths of 5′and 3′ uncoding regions were 96 and 454 nucleotides, respectively. Compared with the standard DEN-2 virus (NGC strain) and three DEN-2 (strains 04, 43 and 44) isolates from other regions of China, the nucleotide sequence homology were　94.0%, 92.8%, 93.9%, 93.9% and the amino acid sequence homology were 97.9%, 97.2%, 97.7%, 97.9% respectively. A phylogenetic tree was produced by comparing E/NS1 gene junction of 47 strains of dengue 2 virus. Analysis results showed that FJ-10 strain was closely related to Indonesia and Sri Lanka strains and fell into genotype Ⅳ. Conclusion　The complete genomic sequence of FJ-10 strain is similar to that of the other dengue 2 viruses, but the genotype of FJ-10 strain is different from that of DEN-2 strains 04, 43 and 44 isolated from other regions of China.