title: Hyper-recombining recipient strains in bacterial conjugation.
abstract: Using a direct enrichment and screening procedure, mutants of Escherichia coli have been isolated in which recombination frequencies for several intragenic Hfr X F- crosses are significantly higher (twofold to sixfold) than in the parental strains. These hyper-recombination mutations comprised five new mutS- and one new mutL- allele. Together with other known mut- alleles, they were analyzed for effects on intragenic recombination using several types of crosses. Hyper-recombination was found for mutS-, mutL-, mutH (= mutR)- and mutU (= uvrD)-, with the largest effects seen for certain alleles of uvrD; these resulted in over 20-fold excesses in recombinant production for Hfr X F- crosses and F'-chromosome homogenotization. Spontaneous mutator ability was not always correlated with degree of hyper-recombination.
mesh_terms: D000483:Alleles; D003227:Conjugation, Genetic; D003433:Crosses, Genetic; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects; D005816:Genetic Complementation Test; D005838:Genotype; D009154:Mutation; D013045:Species Specificity; D014466:Ultraviolet Rays