pronuclear transfer

Pronuclear transfer is a method used in assisted reproductive technologies, specifically in producing a "three-parent baby." This technique involves creating a zygote (fertilized egg) from the intended parents' sperm and egg. The pronuclei (the nuclei of the sperm and egg) are then removed from this zygote and transferred into a donor egg that has also been fertilized but had its own nucleus removed. The resulting zygote, containing genetic material from both intended parents and mitochondrial DNA from the donor, is then implanted into the mother's uterus.1

This process is a form of mitochondrial replacement therapy (MRT), which aims to prevent the transmission of mitochondrial diseases. Mitochondria, which contain their own DNA (mtDNA), are inherited solely from the mother. If the mother's mtDNA has mutations causing disease, MRT can replace it with healthy mtDNA from a donor. This technique is distinct from somatic cell nuclear transfer (SCNT), which involves transferring the nucleus of a body cell into an enucleated egg cell for cloning purposes.123