For the first time, an integrated PCR and sequence molecule analysis has been performed. Heritable recessive point mutations of two different genes of Drosophila melanogaster induced by 60Co γ-ray at the dose of 40 Gy were examined. The results from the PCR analysis of the above-mentioned gene mutations were presented at the seminar, demonstrating different frequency of two main types of DNA changes (PCR- and PCR+).

Further investigations of the PCR+ mutations through the sequence analysis made it possible to outline a complex spectrum of DNA microchanges, underlying the mutations of this kind, which includes substitutions of different bases, microdeletions, microinsertions and gene conversions. The peculiarities of this spectrum in the two genes were discussed and the relative frequency of each type of changes within their common spectrum was evaluated. The analysis of the distribution of these changes on the exon-intron diagram of both genes was presented. Possible mechanisms for mismatch repair of primary DNA damages, causing the observed heritable changes were under discussion.