Expression of full-length and truncated forms of crystal protein genes from Bacillus thuringiensis subsp. kurstaki in a baculovirus and pathogenicity of the recombinant viruses.

Full-length and truncated forms of the crystal protein gene cryIA(b) derived from Bacillus thuringiensis subsp. kurstaki HD-1 and full-length cryIA(c) gene of B. thuringiensis subsp. kurstaki HD-73 were introduced into the genome of the baculovirus Autographa californica nuclear polyhedrosis virus, in place of the polyhedrin gene. All gene constructs were expressed at high levels in insect cells and insects upon infection with the recombinant viruses. The protein products were shown to be biologically and immunologically similar to the natural crystal protein. The expressed proteins formed crystals (in insects) up to 10 times bigger (in length) than their bacterial counterpart. The LT50 values for recombinant viruses were not significantly shorter than wild-type virus.