A genetic characterization of the model baculovirus, Autographa californica nuclear polyhedrosis virus (AcNPV), will provide fundamental information regarding the mechanism of infection of this environmentally prevalent group of viruses, some of which are currently employed commercially as biological pesticides. Genetic analysis includes the identification and characterization of the DNA genome by restriction endonuclease analysis as well as the isolation and initial characterization of a series of temperature-sensitive mutants of AcNPV. Initial characterization of the AcNPV mutants will include complementation analysis and determination of developmental defects including defects in nonoccluded virus formation or polyhedral occlusion body formation. Mapping of the genetic mutants by marker rescue and alignment with a physical map of the DNA genome will also be pursued.