Comparative assessment of mutations in mtDNA of x-irradiated mice using mismatch-specific endonuclease and temporal temperature gradient electrophoresis

Abstract

Mutations in brain mtDNA of mice X-irradiated to 5 Gy were determined using a mismatch-specific endonuclease (CEL I) and by temporal temperature gradient gel electrophoresis (TTGE). The CEL I nuclease method allows simultaneous analysis of multiple DNA samples and proves to yield better results than TTGE; it is more sensitive, quite reproducible, and economical, requiring no complicated equipment. The CEL I nuclease assay for mtDNA mutations in the brain of x-irradiated mice has shown that the amount of mutant mtDNA copies is markedly reduced (2–3 times) from the 8th to the 28th day after irradiation, while the overall amount of mtDNA copies in the brain tissue remains fairly constant over this period, though lower than in the control. It can be suggested that mutant mtDNA copies are eliminated from the tissues of irradiated animals in the postirradiation period.