Mitochondria and oocyte maturation
Mitochondria play a central role in cellular energy metabolism. Mitochondrial genome (mtDNA) is specific with a maternal transmission. Defects of mtDNA, both quantitative (depletion) but also qualitative (mutation) were observed in patients with reproductive disorders, suggesting that a mitochondrial deficit could cause a failure of oocyte maturation. In our experience, some mtDNA point mutations would be subject to negative selection during female gametogenesis, with a threshold rate depending on the mutation. Below this threshold, the presence of mtDNA mutations would not impact oocyte maturation nor early embryonic development, as evidenced by the large number of oocytes and embryos carrying high mutation rates in our series.