[Theoretical analysis of mechanisms of spontaneous and induced mutations in DNA based on repeated sequences].

Mechanisms of spontaneous and chemically induced point mutations' emergence in DNA have theoretically been investigated using the statistical weight method. We have analysed 12 nucleotide sequences containing 95 point spontaneous mutations and 3 sequences comprising 30 mutations induced by such mutagens as 4'-hydroxymethyl-4,5',8-threemethylpsoralene, natrium bisulfite, hydroxylamine. The possibility of occurrence of point mutations by repair correction of heteroduplexes formed via mispairing of imperfect direct and inverted repeats in DNA has been studied. Statistically reliable connection of position of spontaneous mutations in DNA with repeats has been revealed for a number of nucleotide sequences. Statistically reliable connection of mutations induced by 4'-hydroxymethyl-4,5',8-threemethylpsoralene with imperfect repeats is also shown.