[Mutagenic effects of gamma-rays on plasmid DNA in Escherichia coli].
A purified and dried DNA of plasmid pKO482 (galK+) is 10 times more resistant to the inactivating action of 60Co-gamma-rays than that of lambda phage. gamma-Irradiation of the plasmid DNA induces forward mutations of galK, the frequency of which increases linearly with the dose. The efficiency of the mutagenic action of gamma-rays on the plasmid galK locus is 10(-12) per 1 rad and per 1 base pair. The mutagenic effect of gamma-radiation but slightly depends upon bacterial recA+ gene and upon the SOS-repair system induced by UV-irradiation of the recipient cells. It is assumed that the premutational lesions induced in the purified DNA by the direct effect of gamma-radiation are fixed into mutations by misreplication.
D004269:DNA, Bacterial / Q000235:genetics* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects*; D005720:Gamma Rays; D009154:Mutation; D010957:Plasmids / Q000528:radiation effects*; D014169:Transformation, Bacterial / Q000528:radiation effects*
D004269:DNA, Bacterial
Mutagennoe deĭstvie gamma-lucheĭ na plazmidnuiu DNK Escherichia coli.