Mechanisms of DNA double-strand break repair and their potential to induce chromosomal aberrations

DNA double-strand breaks (DSB) are considered to be critical primary lesions in the formation of chromosomal aberrations. DSB may be induced by exogenous agents, such as ionizing radiation, but also occur spontaneously during cellular processes at quite significant frequencies. To repair this potentially lethal damage, eukaryotic cells have evolved a variety of repair pathways related to homologous and illegitimate recombination, also called non-homologous DNA end joining, which may induce small scale mutations and chromosomal aberrations. In this paper we review the major cellular sources of spontaneous DSB and the different homologous and illegitimate recombination repair pathways, with particular focus on their potential to induce chromosomal aberrations.