Role of the TK+ phenotype in the stability of pigeonpox virus recombinant.
Insertion of foreign DNA containing the E. coli gpt marker by homologous recombination in the pigeonpox virus (PPV) thymidine kinase (TK) gene and selection for the presence of this DNA in the viral genome produced unstable recombinants after 3 plaque purifications. We highlight the persistence of duplicated TK DNA sequences arising from single crossing over, due to the growth advantage of TK+ virus. Restoration of the TK function by coinsertion of the vaccinia virus TK gene led to stable TK+ recombinants arising from double crossing over.
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Institut National de Recherches Vétérinaires, Uccle, Belgium.
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002478:Cells, Cultured; D002645:Chickens; D003001:Cloning, Molecular; D003434:Crossing Over, Genetic; D004279:DNA, Viral / Q000737:chemistry*; D029968:Escherichia coli Proteins; D005587:Fowlpox virus / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development; D015967:Gene Expression Regulation, Viral; D008969:Molecular Sequence Data; D010430:Pentosyltransferases; D010641:Phenotype; D010957:Plasmids; D011506:Proteins; D011995:Recombination, Genetic; D013937:Thymidine Kinase / Q000235:genetics*; D014162:Transfection; D014779:Virus Replication / Q000235:genetics
D001426:Bacterial Proteins; D004279:DNA, Viral; D029968:Escherichia coli Proteins; D011506:Proteins; D010430:Pentosyltransferases; C071962:Gpt protein, E coli; D013937:Thymidine Kinase