新成人腹泻轮状病毒J19株的全基因组克隆和VP4、VP6和VP7基因序列分析

Cloning of the Complete Genome Set and Sequence Analysis of the VP4,VP6,and VP7 Genes of a Novel Adult Diarrhea Rotavirus Strain J19

为了进一步了解新成人腹泻轮状病毒J19株的基因和蛋白特征,利用一种改良的非依赖核酸序列的单引物扩增方法扩增J19株的11个基因,克隆到pMD18-T载体中并进行测序。在此基础上,将主要抗原蛋白VP4、VP6和VP7的蛋白序列与其它轮状病毒的相关蛋白序列进行比较分析并对VP6蛋白序列做遗传进化分析。结果获得J19株11个基因的全长基因序列。基因序列分析表明J19株的第3、6和第9基因分别长2 512bp、1 287bp和820bp,它们分别预测编码抗原蛋白VP4(823aa)、VP6(396aa)和VP7(258aa)。组成J19株的VP4、VP6和VP7蛋白序列对B组轮状病毒的CAL株、IDIR株以及ADRV株的相关蛋白序列的一致性分别是27.6%、38.5%和22.3%。对分组抗原蛋白VP6的遗传进化分析表明,J19株在进化树上的位置靠近外群蛋白分支以及A、B和C组轮状病毒分支的根部,而且它比较偏向于B组轮状病毒的分支。J19株的VP4、VP6和VP7蛋白序列与其它轮状病毒的相应蛋白序列存在显著差异。VP6蛋白序列的遗传进化分析表明J19株可能是一个新组轮状病毒的代表性毒株;同时,它也可能是一个与B组轮状病毒的起源和进化密切相关的毒株之一。关于新成人腹泻轮状病毒J19株11个基因的克隆及VP4、VP6和VP7基因的序列分析,这是第一次报道。

For better understanding the molecular characteristics of the genes and proteins of a novel adult diarrhea rotavirus strain J19 （NADRV-J19）, the complete genome set of NADRV-J19 was amplified by an improved single primer sequence-independent amplification method, cloned into pMD18-T vector, and sequenced. Protein sequences of VP4, VP6, and VP7 of J19 strain were aligned with those of other rotaviruses and phylogenetic analysis based on VP6 sequence was made with the other rotaviruses. Sequence analysis of 11 full-length genes of J19 revealed that genomic segments 3,6, and 9 of NADRV-J19 encoding VP4, VP6, and VP7 were 2512, 1287, and 820bp in length, and their deduced proteins were 823aa,396aa,and 258aa respectively. Identities of VP4, VP6, and VP7 proteins of J19 strain to that of group B rotavirus strains CAL, IDIR ,and ADRV were 27.6 %, 38.5 %, and 22.3 % respectively. Phylogenetic analysis based on VP6 proteins showed that J19 was positioned closely to outgroups and the ancestral nodes of rotavirus group A, B, and C lineages, although with a preferred association with group B lineages. The above results showed that VP4, VP6, and VP7 proteins of J19 differed significantly from those of the other rotaviruses. J19 would be a representative strain of a novel rotavirus group and would be a strain closely related to the evolution and origin of group B rotaviruses. Up to now, this is the first report concerning to the cloning of 11 gene segments of NADRV-J19 and sequence analysis of the genes of NADRV-J19 encoding VP4, VP6, and VP7 proteins.