Mitochondria in Human Fertility and Infertility

In human spermatozoa and oocytes (and their surrounding granulosa cells), mitochondria carry out important functions relating to human fertility and infertility. Sperm mitochondria are not transmitted to the future embryo, but are closely related to the generation of energy needed for sperm movement, capacitation, and acrosome reactions, as well as for sperm-oocyte fusion. On the other hand, oocyte mitochondria produce energy required for oocyte meiotic division and their abnormalities can thus cause oocyte and embryo aneuploidy. In addition, they play a role in oocyte calcium metabolism and in essential epigenetic events during the oocyte-to-embryo transition. They are transmitted to the future embryos and may thus cause hereditary diseases in the offspring. Due to the long life span of the female germ cells, the accumulation of mitochondrial DNA abnormalities often causes ovarian aging. Mitochondrial substitution therapy is the only way of dealing with these issues nowadays. New therapies based on mitochondrial DNA editing are under investigation.

Automated summary

Mitochondria in human sperm and oocytes play important roles in human fertility and infertility. Sperm mitochondria are involved in providing energy for sperm movement, capacitation, and fusion with oocytes, while oocyte mitochondria are essential for oocyte meiotic division and calcium metabolism. Abnormalities in these mitochondria can lead to aneuploidy in oocytes and embryos, as well as hereditary diseases in offspring. Accumulation of mitochondrial DNA abnormalities can also contribute to ovarian aging. Mitochondrial substitution therapy and mitochondrial DNA editing are being explored as potential treatments.