Abstract: | In analytical review is considered the possibility of the insertion of mitochondrial DNA (mtDNA) fragments into the nuclear genome of cells, exposed ionizing radiation (IR). Many studies show that integration fragment mtDNA in nuclear genome, as well as its fastening as NUMT-pseudogenes, proceed at ancient periods of the evolutions not only, but also at more late periods. The number of the investigations shows that under influence endogenous reactive oxygen species, chemical agent, UV-light and IR mtDNA is damaged with greater frequency, than nucleus DNA. Furthermore, the repair systems in mitochondria are low efficiency. In irradiated by IR cells mtDNA fragments can transition from the mitochondria to the cytoplasm. The binding of mtDNA fragment to a complex with proteins provides them the protection from nuclease destroying. Possibly, at such safe condition they and are carried to nucleus. At inductions of DNA double-strand breaks (under the action of IR and activated their reparation) mtDNA fragments may be inserted to nuclear genome. Such integration of mtDNA to nuclear genome, with shaping NUMT-pseudogenes de novo, may be proceed in irradiated cells in the course of the reparations DNA double-strand breaks by the nonhomologous end-joining pathway. These insertions of mtDNA can cardinally change the structure of nuclear genomes in area of their introduction and render the essential influence upon the realization of genetic information. Available information in literature also allows to suppose that integration mtDNA in nuclear genome can proceed and at raised genomic instability observed in cells at post radiation period. It in equal extent pertains and to malignant cells with raised by instability mitochondrial and nuclear genomes. As the most efficient agent, initiating insertion fragment mtDNA in nuclear genome, is considered ionizing radiation. |