SUMMARY. Double-strand DNA breaks (DSBs) resulting from cel-lular metabolic processes and external factors are a serious threat to the stability of the genome. Therefore, the cells have different molecular mechanisms for the efficient repair of this type of da-mage. In this review we consider two main biochemical pathways of double-strand DNA breaks repair in eukaryotic cells – DNA strands nonhomologous end joining and homologous recombination between sister chromatids or chromatids of homologous chromosomes. Numerous data obtained recently for various eukaryotic cells suggest that complex interplay between the major DSB repair pathways normally facilitate the efficient repair and maintenance of the structural and functional genome integrity, but at the same time, under conditions of genotoxic factors exposure may induce increased genomic instability.
Keywords: double-strand DNA breaks, repair, genom instability, interplay between DNA repair pathways, non-homologous end joining, homologous recombination, alternative DSB repair pathway
