Physical Map of the DNA of a Mamestra brassicae Nuclear Polyhedrosis Virus Variant Isolated from Spodoptera exigua

The D N A of a multiply-enveloped nuclear polyhedrosis virus (MNPV) of the cabbage moth Mamestra brassicae (Mb), isolated from the beet armyworm Spodoptera exigua, was analysed using restriction endonucleases SmaI, BamHI, BgllI and PstI. The size of the viral D N A was calculated to be about 152 kilobase pairs. Mapping of restriction sites on the D N A was accomplished by hybridization of 32 P-labelled D N A fragments to single and double digests of the M b M N P V genome. Mapping of the putative polyhedrin gene was used to orient the physical map. The relevance of this map to the structural organization of the D N A of MbMNPV isolated from different geographical areas is discussed.