Construction of transposon-mediated baculovirus vector and expression of green fluorescent protein in insect cells and larvae

A transposon-shuttle vector Hanpvid was constructed by using wild-type genomic DNA fromHeliothis armigera nuclear polyhedrosis virus (HaNPV). It could replicate inE. coli cells as a large plasmid and remain infectious when being induced into insect cells. Hanpvid comprises HaNPV DNA and a transposon cassette which includes a miniF replicon, a kanamycin resistance gene (kan), lacZa and an attachment site for Tn7 (attTn7). Recombinant virus rHa-FaGP was obtained after transposition of a donor plasmid carrying green fluorescent protein gene (gfp) and polyhedrin gene (ocu) into attTn7. SDS-PAGE analysis shows that both gfp and ocu genes were highly expressed inHeliothis armigera cells. Green Hemolymphocytes can be seen under a fluorescent microscope 4 d after recombinant virus rHa-FaGP infected the third-instar larvae. The infected larvae show strong green fluorescence 6 d post infection.