title: [Instability study of Escherichia coli strains containing hybrid plasmids with threonine operon fragments].
abstract: The stability of Escherichia coli strains carrying hybrid plasmids which contain ColE1-like replicon and threonine operon genes was studied. It was shown that the main reason for instability is the loss of a plasmid. The second reason for instability is the rec-dependent recombination that leads to formation of new plasmids. All experiments where instability of strains was observed, can be quantitatively described by the model that presumes a random loss of plasmids in cell population with a frequency of about 7.10(-4), which results in diappearance of plasmid-borne cells due to their low growth rate. Instability increases during the stationary phase but it is not easy to quantitatively estimate this process.
mesh_terms: D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005822:Genetic Vectors; D009693:Nucleic Acid Hybridization; D009876:Operon; D010957:Plasmids; D013912:Threonine / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D013912:Threonine
vernacular_title: Issledovanie nestabil'nosti shtammov Escherichia coli, soderzhashchikh gibridnye plazmidy s fragmentami treoninovogo operona.