title: [Expression of Pseudomonas aeruginosa phage transposons in Pseudomonas putida PpG1 cells. II. Zygotic induction--a necessary condition for the formation of defective lysogens].
abstract: The transfer of hybrid plasmid RP4::PT (where PT is the genome of a transposable phage specific for Pseudomonas aeruginosa) into recipient cells of P. putida strain PpG1 occurs with the same frequency as into P. aeruginosa, the homologous host for PT. Approximately 1/3 of all PpG1 exconjugants carrying RP4 markers lost the capability to produce viable PT phage. In contrast, in a cross with homologous recipient P. aeruginosa all exconjugant clones contained nondefective prophages in the hybrid plasmids. Zygotic induction is an obligatory condition for detection of PpG1 exconjugants with defective phages. The defective prophages in RP4::PT hybrid plasmids have deletions of different size; the other carry mutations indistinguishable from point mutations in an essential phage gene. Some of deletions also cover plasmid genes. At least some of the defective prophages, including deleted ones, have arisen in the recipient cells of P. putida after transfer of the hybrid plasmid.
mesh_terms: D001435:Bacteriophages / Q000235:genetics*; D002872:Chromosome Deletion; D004251:DNA Transposable Elements; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D005814:Genes, Viral; D008242:Lysogeny; D009154:Mutation; D010957:Plasmids; D011549:Pseudomonas / Q000235:genetics*; D011550:Pseudomonas aeruginosa; D013997:Time Factors; D014775:Virus Activation
chemical_list: D004251:DNA Transposable Elements
vernacular_title: Ekspressia fagov-transpozonov Pseudomonas aeruginosa v kletkakh Pseudomonas putida PpG1. Soobshchenie II. Zigotnaia induktsiia--obiazatel'noe uslovie vozniknoveniia defektnykh lizogenov.