DNA homology among subgroup A, B, and C baculoviruses.

The DNA homology among 18 baculoviruses from subgroups A, B, and C was compared using restriction endonuclease analysis, DNA hybridization, and Southern blot hybridization. Restriction enzyme patterns for each of the viral DNAs compared was unique. Viral DNA homology was evaluated by hybridizing 32P-labeled viral DNAs to unlabeled DNAs immobilized on nitrocellulose filters. Hybridization conditions were varied by using a range of formamide concentrations during annealing. The apparent DNA homology among viruses was from 2- to 10-fold different depending on the stringency of the hybridization conditions. At the least stringent conditions, all viral DNAS from subgroup A, B, and C had detectable sequence homology. Homologous DNA sequences were mapped, using Southern blot analysis, to several regions of the Autographa californica nuclear polyhedrosis virus (AcMNPV) genome. Subgroup A, B, and C viral DNAs had sequences homologous to AcMNPV EcoRI fragment I and all subgroup A and B viral DNAs hybridized to AcMNPV EcoRl fragments L and M.