Mutagene effect on Escherichia coli bacteria of 8-oxo-2-deoxyguanosine - a DNA base damage product induced by oxygen radicals and irradiation

The effect of 8-oxo-2'-deoxyguanosine (80oxo-dG) (8-hydroxydeoxyguanosine) - a DNA base damage product induced by oxygen radicals and irradiation on survival and mutagenesis in Escherichia coli strains C-600 and P-687 was investigated. Bacterial survival at all 8-oxo-dG concentrations tested was shown to be no lesser than in the control. A non-linear dependence of mutagenesis on the concentration was observed. Linerar increase in the amount of revertants took place at concentrations of 8-oxo-dG lower than 1 mM, and being kept constant at higher concentrations. Weak induction of the SOS response was observed within the wide range of 8-oxo-dG concentration values, which points to a lack of genotoxicity and independence of mutagenesis on SOS repair