Sequence Analysis Of VP7 Gene Of Rotavirus Group A And B Strains Of Different Areas In China

ObjectivesTo study strain DQ-1 VP7 gene variation of human group A rotavirus( GARV) from da-qing district, we analyzed and compared its gene sequence and protein structure with standard strain and field strains of China which had been sequenced.MethodsFirstly we extract total RNA of DQ-1, the gene that encoded the structural protein VP7 gene of GARV was amplified from isolated strain DQ-1 by reverse transcription polymerase chain reaction(RT-PCR).Then the products of RT-PCR were ligated with plasmid pMD18-T and transformed into E.coli competent cells JM109. Analyzed by PCR detection ,it was showed that the VP7 gene was cloned into pMD18-T and the recombinant plasmids were constructed by PCR detection. The VP7 gene of GARV strain DQ-1 was then sequenced. The identity to other GARV was analyzed by software DNAStar,the secondary structure of DQ-1 VP7 mRNA was predicted by software RNA structure 4.4 ,and the protein of VP7 was analyzed by Predictprotein.ResultsThe nucleotide sequence of DQ-1 VP7 gene showed high identities (more than 90 %) to that of other human GARV such as T73,R96-197 and Wa which belongs to G1 Genotype, while identities to that of G2 Genotype such as DS-1 and G3 Genotype such as SA11 and G4 Genotype such as J-4621 were lower than 80%.The secondary structure of DQ-1 VP7 mRNA was constructed by about 20 stem-loop structures.The polypeptide encoded by DQ-1 VP7 contains 354 amino acids,the protein contains two potential N-linked glycosylation sites and some phosphorylation sites. Compared with other GARV DQ-1 VP7 demonstrated 97.5% and 94.6% of amino acids similarity with T73 and Wa respectively,but only 74.4 %,79.4% and 75.2% with DS-1,SA11 and J-4621. So, we might draw the conclusion that strain DQ-1 belongs to G1 serotype.ConclusionsThe sequence analysis revealed that the VP7 gene of DQ-1 shared higher identities with field strains of G1 serotype ,but showed differences with standard strain ,these results might give a molecular biological evidence to the inducement and development of the GARV vaccine. ObjectivesTo compare gene and amino acid sequence identity to other group B rotavirus,and further analyse the Phylogenetic relationship of group B ADRV rotavirus that spreads different areas of china, we cloned and sequenced the structural protein VP7 gene of four strains human group B ADRV rotavirus in different areas of china.MethodsWe designed primers accordinging to the article, and extracted the RNA from four strains,then,VP7 genes were amplified by reverse transcription polymerase chain reaction(RT-PCR). The products of RT-PCR were ligated with plasmid PCR^TMII and transformed into E.coli competent cells.Analyzed by PCR detection.it was showed that the VP7 gene was cloned into PCR^TMII and the recombinant plasmids were constructed. The VP7 genes of four strains were then sequenced. The identity to other group B rotavirus was analyzed by software DNAStar6.0, and thus the phylogenetic tree was established.Results The results show that the gene sequence identity between the four strains is 97.3%～98.8%, the ammo acid sequence identity is 95.2%～99.3%; the gene sequence identity to ADRV is 98.2%～100%, the amino acid sequence identity is 97.4%～100%; the gene sequence identity to foreign strains in India and Bangladesh is 90.1%～92.5%, the amino acid sequence identity is 92.3%～95.6%.ConclusionsThe sequence analysis revealed that all strains of human group B ADRV rotavirus belongs to the same serotype, these results can give a molecular biological evidence to the inducement of the group B ADRV rotavirus vaccine.They can also give a molecular virul evidence to the viewpoint that "Virus exists in the form of population"and "Inside the population of the Virus exists in a'variation spectrum'.