CHARACTERIZATIONS OF NATURAL AND INDUCED POLYHEDRIN GENE MUTANTS OF BOMBYX-MORI CYTOPLASMIC POLYHEDROSIS VIRUSES

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) polyhedrin gene fro m natural mutant strain B, B-2 and P was cloned and the amino acid seq uence was compared with that of wild-type virus (strain H). Chimeric p olyhedrin genes (8 types) containing only one site of mutation within the amino acid sequence were also constructed. Fifteen types of polyhe drin genes were introduced into a baculovirus expression vector and he xahedral, acicular, pyramidal, or amorphous polyhedra were formed in i nfected cells. These results demonstrated that the shape of polyhedra as well as the crystallization pattern of the polyhedrin could be chan ged by mutations at respectively N-terminal and C-terminal regions of BmCPV polyhedrin gene.