CHARACTERIZATION OF THE DNA OF A NUCLEAR POLYHEDROSIS-VIRUS SELECTED FOR AN INCREASED RATE OF VERTICAL TRANSMISSION

A strain of Spodoptera frugiperda nuclear polyhedrosis virus (SfNPV) was selected in previous research for an increased rate of vertical transmission by isolating it from pupae that had been infected through vertical transmission. Differences were detected between the wild (PW) and the selected (PS) isolates of SfNPV when the viral DNA was digested with the restriction enzymes EcoRI, HindIII, and BamHI. The restriction profiles indicated a possible DNA insertion in the PS isolate. Probes with P-32-labeled SfNPV DNA and S. frugiperda cellular DNA indicated that there was only viral DNA, not S. frugiperda cellular DNA, in the genome of the PS isolate. Therefore, the differences between the PW and the PS isolates were due to rearrangement of DNA within the viral genome. Cluster analysis based on numbers of DNA fragments shared among SfNPV isolates from the EcoRI, HindIII, and BamHI enzyme digests indicated that the PS isolate had one of the more unique genomes when compared with the PS isolate and 22 other SfNPV isolates analyzed in previous research. However, the PS DNA enzyme digests did not fall outside the range of patterns of digests observed in the natural isolates. (C) 1994 Academic Press, Inc.