title: Noncytopathic mutants of Newcastle disease virus.
abstract: We have isolated a novel class of mutants of Newcastle disease virus which are less cytopathic than their virulent parent but are still capable of infectious virus production. Unlike wild-type virus, the mutants did not form plaques after 2 days of incubation; they did, however, make hemadsorbing spots. The mutants range in production of infectious virus from 10 to 200% of that of the wild type. They were less cytopathic in a single cycle of infection by light microscopy, loss of protein from the plate, and inhibition of total protein accumulation. All of the mutants exhibited extended mean embryo death times, a correlate of virulence in the adult animal.
mesh_terms: D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D003588:Cytopathogenic Effect, Viral; D006382:Hemadsorption; D009154:Mutation; D009522:Newcastle disease virus / Q000254:growth & development / Q000472:pathogenicity*; D011506:Proteins / Q000378:metabolism; D014774:Virulence; D014779:Virus Replication
chemical_list: D011506:Proteins