Fertilizable oocytes reconstructed from patient's somatic cell nuclei and donor ooplasts

The only assisted reproduction treatment now available for women with ovarian failure or irreparable oocyte defects is oocyte donation. However, some women experience psychological barriers to the recourse to donor oocytes, related to the lack of contribution of their proper genes to the progeny. A pilot study in humans suggests that this problem may be overcome by the development of techniques for haploidization of somatic cell nuclei, allowing the formation of new oocytes bearing the complete nuclear genome of the patient. Somatic cell nuclei were obtained from cumulus cells of a patient who failed to produce fertilizable oocytes and were transferred into enucleated oocytes (ooplasts) from a donor. Out of six ooplasts injected with the somatic cell nuclei and fertilized with spermatozoa from the patient's husband, signs of haploidization were detected in three oocytes, two of which subsequently started embryonic development and were cryopreserved for eventual future transfer to the genetic mother. These data show that human oocytes can be used for both reprogramming and haploidization of somatic cell nuclei, allowing reconstruction of genetically own oocytes for patients without, or with seriously disturbed, ovarian function.