Female germ cells comprise essentially immortal cell line which transmits the nuclear and mitochondrial genom-es throughout generations. Heteroplasmy is defined as the presence of two types of mtDNA in the cell, the wild type mtDNA and the mutated mtDNA. It is considered that cells possess natural mechanisms preventing from accumula-tion of mtDNA mutations. However, this process is not always fully sufficient and its efficiency may be additionally impaired during aging. This results in a considerable proportion of mitochondrial abnormalities and diseases in the human population. Therefore, scientists are looking for methods that could improve the quality of mitochondria as well as delay the adverse effects of aging processes that negatively affect both the quality of the mitochondrial ge-nome and the fertility in mammals.