| Rotaviruses (RVs) are members of the family Reoviridae, and cause severe gastrenteritis in the young of various animal species. In humans, RV infections lead to the death of more than600000in children each year. RV is a double-strained RNA (dsRNA) virus of icosahedral symmetry, measures70nm in diameter, and consists of three layers without envelope. RV possesses a genome of11segments of dsRNA, which encodes6structural proteins (VP1-VP4, VP6, VP7) and6non-structural proteins (NSP1-NSP6). RVs can be classified into seven groups (A to G) according to the antigenic specificity of the VP6protein. Group A RVs are the major cause of acute gastroenteritis in infants and young children.The structural protein VP3of RV plays a very important role in virus genome transcription. In this article,(1) by gene cloning and expression technology, a recombinant expression plasmid that carrying the full-length open reading frame (ORF) of the VP3of a group A RV strain TB-Chen was constructed, and expressed in E.coli BL21(DE3) cells, and (2) phylogenesis and genotypes of VP3were studied. The results showed that the expressed rVP3exists in the form of inclusion body, and could be detected out using guinea pig serum antibodies against the whole structural proteins of RV strain SAIL RVs in Group A discovered so far could be classified into at least7genotypes, based on the diversity of the VP3open reading frame (ORF) sequences. VP3of strain TB-Chen was defined into genotype M2. Three VP3genotypes (M1-M3) have been found in humans, and genotypes M4and M7were only found in birds. Genotying results indicated that RVs with different VP3genotypes have specific host ranges, RVs possessing the same genotype could infect different species, and the same species could be infected with different genotypes. The results obtained in the present study are important for further studying structure and function of the VP3, and help developing novel effective vaccines, diagnostic reagents and drugs in future. |
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