Pronucleus is the nucleus of a sperm or an egg cell during the process of fertilization. The sperm cell becomes a pronucleus only after the sperm enters the ovum, but before the fusion of genetic material of the sperm and egg.
The technique of pronuclear transfer involves the transfer of pronuclei from one zygote to another. Under this technique, first This technique first the healthy donated egg/s (provided by the mitochondrial donor) is fertilised with the intending male parent sperm.
Pronuclear Transfer has the potential to prevent mitochondrial disease in the offspring as Mitochondrial DNA is transmitted maternally. In pronuclear transfer, the mother’s egg is first fertilized with the sperm which produces a zygote. The pronuclei of the egg and sperm are then removed from the zygote and inserted into a donor egg that has been fertilized and has had its own nucleus removed. The zygote derived from the donor egg is then implanted into the mother’s uterus.