title: Deletions of the terminal sequences in the genomes of the white pock (u) and host-restricted (p) mutants of rabbitpox virus.
abstract: The DNAs of wild-type rabbitpox virus (u+.p+), and selected u (white pock, u.p+) and p (white pock, PK-15 cell non-permissive, u.p) mutants were compared by restriction enzyme analysis. The cleavage fragments produced by digestion with HindIII or EcoRI endonucleases were separated by agarose gel electrophoresis. Deletions of approx. 10 x 10(6) were recognized at the right-hand terminus of each u mutant (three isolates), whereas deletions of 5 x 10(6) to 20 x 10(6) were detected at the left-hand terminus of each p mutant (nine isolates), Rapidly renaturing terminal restriction fragments, indicative of the covalent cross-links, were only found at the terminus unaffected by deleted sequences. Recombinant viruses that were wild-type in both genetic characters and in restriction pattern were recovered from mixed infections involving u and p mutants, but no genetic interaction was detected between crosses involving only u or p mutants. The p mutants were divided into two non-permissive classes dependent on their biochemical expression in PK-15 cells: the 'early' class which failed to replicate virus DNA and synthesized only the 'early' polypeptides and the 'late' class which appeared to be normal both in virus DNA and polypeptide synthesis. There was no correlation between the extent of the left-hand terminal deletion and the extent of permissiveness of the p mutants in PK-15 cells.
mesh_terms: D000818:Animals; D002460:Cell Line; D004262:DNA Restriction Enzymes; D004279:DNA, Viral / Q000032:analysis / Q000096:biosynthesis / Q000235:genetics*; D005814:Genes, Viral; D009154:Mutation; D011212:Poxviridae / Q000235:genetics*; D011995:Recombination, Genetic; D013552:Swine; D014616:Vaccinia virus / Q000235:genetics* / Q000254:growth & development; D014764:Viral Proteins / Q000096:biosynthesis
chemical_list: D004279:DNA, Viral; D014764:Viral Proteins; D004262:DNA Restriction Enzymes