title: Bacterial mutants defective in plasmid formation: requirement for the lon + allele.
abstract: Bacterial mutants defective in plasmid formation were selected for their inability to be transduced to chloramphenicol resistance by bacteriophage PlCM. The mutants isolated are indistinguishable from a lon mutant strain. Both the lon strain and the mutants isolated here show very poor lysogenization by P1 and very low transduction to Gal(+) by the plasmid formation of the lambdagal(8)-Nam7am53cI(857). The lon(+) gene function of the host bacteria is indispensable for plasmid formation, even though P1 and lambda(+) can grow normally on the lon strains and lambda(+) can be integrated normally in lon as well as in the lon(+) bacteria. Phage mutants that can persist as plasmids in lon strains were isolated from P1CM. The function of the lon(+) gene is discussed with regard to plasmid formation.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D002874:Chromosome Mapping; D003090:Coliphages; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification / Q000528:radiation effects; D005111:Extrachromosomal Inheritance; D005690:Galactose / Q000378:metabolism; D005796:Genes; D005827:Genetics, Microbial; D008242:Lysogeny; D009154:Mutation; D011830:Radiation Effects; D011995:Recombination, Genetic; D013696:Temperature; D014161:Transduction, Genetic; D014466:Ultraviolet Rays
chemical_list: D002701:Chloramphenicol; D005690:Galactose