title: The stabilization of episomal integration by genetic inversion: a general hypothesis.
abstract: In F' cells of Escherichia coli K12, recombination in the region of genetic duplication between chromosome and F-genote produces a rapid alteration between the integrated and detached states of the episome. Nevertheless, F' strains can give rise to Hfr cells in which the F-genote has undergone stable integration. We have found that one such Hfr has retained the genetic duplication as well as the recombination proficiency of the parental F' strain; to account for the failure of recombination to detach the episome in this Hfr, we have postulated the inversion of one of the duplicated regions. A general model is presented, showing that an inversion must prevent episome detachment by any combination of genetic crossovers.
mesh_terms: D002869:Chromosome Aberrations; D002876:Chromosomes, Bacterial; D003090:Coliphages; D003227:Conjugation, Genetic; D003434:Crossing Over, Genetic; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D005111:Extrachromosomal Inheritance; D005643:Fucose / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D005947:Glucose; D007535:Isomerases / Q000096:biosynthesis; D008242:Lysogeny; D008954:Models, Biological; D011830:Radiation Effects; D011995:Recombination, Genetic; D014466:Ultraviolet Rays
chemical_list: D005643:Fucose; D007535:Isomerases; D005947:Glucose; D005690:Galactose