[Induction of the Tn10 precise excision in E. coli cells after accelerated heavy ions irradiation]. / Induktsiia tochnoi ékspozitsii transpozona Tn10 v kletkakh E. coli pri obluchenii uskorennymi ionami s raznoi lineinoi peredachei énergii.

The influence of the irradiation of different kinds on the induction of the structural mutations in the bacteria Escherichia coli is considered. The regularities of the Tn10 precise excision after accelerated 4He and 12C ions irradiations with different linear energy transfer (LET) were investigated. Dose dependences of the survival and relative frequency of the Tn10 precise excision were obtained. It was shown, that the relative frequency of the Tn10 precise excision is the exponential function from the irradiation dose. Relative biological efficiency (RBE), and relative genetic efficiency (RGE) were calculated, and were treated as the function of the LET.

[Regularities of excising transposon Tn10 in rec-mutant E. coli cells exposed to gamma radiation]. / Zakonomernosti ékstsizii transpozona Tn10 v kletkakh rec-mutantov E. coli pri gamma-obluchenii.

The regularities of gamma-induced excision of transposon Tn10 in different rec-strains of E. coli cells after gamma-irradiation have been studied. The survival of cells and relative frequency of the Tn10 elimination as a function of the 137Cs gamma-radiation doses were investigated. RecN and recA-mutants of E. coli were used for study of the role of rec-genes in the gamma-induced transposon excision. It was shown that the induced excision in the recN mutant was reduced. The transposon excision in the recA mutant was not revealed. The obtained results let to conclude that recA, and recN genes are involved not only in DNA repair processes but also in the gamma-induced transposon excision in bacteria.