title: Lethal zygosis in recombination-deficient mutants of Escherichia coli.
abstract: Use of nonselective medium for plating cells following mating has revealed that Rec recipient strains of E. coli may be killed as a result of conjugation. Sensitivity of RecA-, RecB-, and RecC- recipients increases with ratio of donor: recipient cells in mating mixtures and with time of mating. A Rec+ recipient shows no lethal zygosis in these experiments performed without aeration. Cell contact does not seem to be responsible for the sensitivity of Rec- strains, since lethality is prevented when cell contact is permitted but DNA transfer is not. Thus, an event(s) occuring subsequent to entry of donor DNA appears to cause lethality in Rec- recipients.
mesh_terms: D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000235:genetics*; D005804:Genes, Lethal; D010641:Phenotype; D011995:Recombination, Genetic