title: Host range mutants of an influenza A virus.
abstract: Temperature-sensitive (ts) mutants of fowl plague virus with a ts-lesion in segment 1 (ts 3, polymerase 1 gene) or segment 2 (ts 90, transport gene) do not form plaques on MDCK cells at the permissive temperature, while the wild type and ts-mutants of other groups are able to do so. This property is correlated with the ts-lesion, since revertants for the ts-lesion of ts 3 and ts 90 again form plaques on MDCK cells. The block on MDCK cells--at least for ts3--may be located in a late function, since viral RNA polymerase and hemagglutinin are formed in almost normal yields. MDCK cells infected with ts 3 or ts 90 exhibit a retarded cytopathic effect at 33 degrees C, but no cytopathic effect at 39 degrees C, at which temperature the infected cells can be passaged and super-infected with the wild type strain. Cells surviving the infection with ts 90 at 33 degrees C sometimes grow out again to a normal monolayer. It is suggested that the spread of virus is inhibited under these conditions.
mesh_terms: D002460:Cell Line; D003588:Cytopathogenic Effect, Viral; D012321:DNA-Directed RNA Polymerases / Q000096:biosynthesis; D005814:Genes, Viral; D006389:Hemagglutinins, Viral; D009980:Influenza A virus / Q000235:genetics / Q000254:growth & development*; D009154:Mutation; D013696:Temperature; D010948:Viral Plaque Assay
chemical_list: D006389:Hemagglutinins, Viral; D012321:DNA-Directed RNA Polymerases