Infectivity of the Recombinant Bombyx mori Nuclear Polyhedrosis Virus Containing Heterogeneous Polyhedrin

The polyhedrin gene(polh) of Autographa californica multicapsid nuclear polyhedrosis virus(AcMNPV) was cloned into the recombinant BmNPV(API4) genome which the polyhedrin gene of Bombyx mori nuclear polyhedrosis virus(BmNPV) was replaced by API4. And a recombinant BmNPV(OAc API4) was obtained. The recombinant virus was able to produce AcMNPV polyhedrin protein and expressed the Arrowhead proteinase inhibitor. The budded virus of the recombinant BmNPV(OAc API4) was able to infect BmN cells, and silkworm larvae using injection while per os inoculation with occluded virus couldn't infect the larvae. It was indicated that per os inoculation of NPV might be concerned with the type of polyhedrin proteins.