[Expression of VP7 from a group A rotavirus G4 field strain in baculovirus system]

The full length of G4 type VP7 cDNA was amplified by reverse transcription and polymerase chain reaction (RT-PCR) from a group A rotavirus field strain CR117 circulated in Beijing. The amplified cDNA was first cloned into pTZ18. Sequence analysis showed 96.9% homology of the deduced amino acid between VP7 of CR117 and ST3. Then the VP7 cDNA of CR117 was subcloned into the transfer vector pBacPAK8 downstream of the polyhedrin promotor. Insect cells were cotransfected with recombinant plasmid pBacPAK8-CR117 and Bsu36I-digested BacPAK6 viral DNA. Recombinant baculovirus containing CR117 VP7 gene was obtained by plaque screen and hybridization identification. Specific VP7 with three different molecular weight was detected by Western blot using hyperimmune serum against Rotavirus strain ST3 (G4 type) when expressed in insect cells.