Physical Maps of Autographa californica and Rachiplusia ou Nuclear Polyhedrosis Virus Recombinants

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Abstract
TN-368 [Trichoplusia ni] cells were infected simultaneously with the closely related A. californica (AcMNPV) and R. ou (RoMNPV) nuclear polyhedrosis viruses. Progeny viral isolates were plaque purified and their DNA were analyzed with restriction endonucleases. Of 100 randomly cloned plaques, 7 were AcMNPV and RoMNPV recombinants, 5 were RoMNPV and 88 were AcMNPV. The recombinants contained DNA sequences derived from both parental genomes. By comparing the restriction cleavage patterns of parental and recombinant DNA, the crossover sites were mapped. A single double crossover was detected in each of the 7 recombinant genomes. Of the 7 recombinants 6 revealed a crossover site mapping between 78 and 89% of the genome. The structural polypeptides of the 7 recombinants and 2 parental viruses were analyzed by polyacrylamide gel electrophoresis and their polyhedrins were identified by tryptic peptide mapping. An analysis of the segregation of 3 enveloped nucleocapsid proteins and of the polyhedrins among the recombinants located the DNA sequences coding for AcMNPV structural polypeptides with MW of 37,000 (a capsid polypeptide), 56,000 and 90,000 and the RoMNPV structural polypeptides with MW of 36,000 (a capsid polypeptide), 56,000 and 91,000. The AcMNPV and RoMNPV polypeptides of MW 37,000 and 36,000, respectively, mapped within 78-89% or 1-29%, the polypeptides of MW 55,000 and 56,000 mapped within 78-29% and the polypeptides of MW 90,000 and 91,000 mapped within 19-56% of the genome. The region of the parental DNA that codes for polyhedrin was located within 70-89% of the genome.