Abstract: A method includes providing a eukaryotic cell including mutant mtDNA in which there is at least one mutation in the mtDNA, allowing the cell to come into contact with an active oxygen species or a chemical species that generates such an active oxygen species in the cell (e.g., hydrogen peroxide) and thereby changing the percentage of mutant mtDNA (mitochondrial genomic DNA) in the cell as a result of the contact. Also featured are cells obtained by the above-described method.

Abstract: It is an object of the present invention to provide a method, which comprises allowing a eukaryotic cell to come into contact with a reactive oxygen species or a chemical species that generates such a reactive oxygen species in the cell, and thereby changing the percentage of mutant mtDNA (mitochondrial genomic DNA) in the cell, and cells obtained by the above-described method. The present invention relates to a method, which comprises allowing cells to come into contact with a reactive oxygen species by, for example, adding the reactive oxygen species such as hydrogen peroxide to a medium containing the cells, and then culturing the cells under suitable culture conditions, so that the percentage of mtDNA having specific mutation in the cell can be changed. In addition, the present invention also relates to cells, in which the percentage of the mtDNA having specific mutation has been changed by the above-described method.