[Mutagenic analysis on the polyhedrin gene (polh) of Bombyx mori nuclear polyhedrosis virus (BmNPV)].

In our early studies, the abnormal shape of the polyhedra of Bombyx mori nuclear polyhedrosis virus (BmNPV) induced by chemical mutagens of MMC. 9-AA and EMS occurred, and the genome of the mutated BmNPV obtained from the successive test had some change in the restriction endonuclease partners of EcoRI, BglII and BamHI. The present studies showed that the arrangement of the crystal lattice of the polyhedrin was disorderly, and the SDS-PAGE electropherogram of the polyhedrin depicted distinct change in comparison with control group. The results of sequencing analysis showed that many point mutations with characteristics of the base substitution had occurred at some sites of the BmNPV polh gene in three mutated groups, and these results funther revealed molecular mutagenesis of the mutagens effective to BmNPV. It was not confirmable that the point mutations of polh gene in the mutated BmNPV have relationship to abnormal shape of the polyhedra.