Cryopreservation of mammalian ovaries and oocytes

The ability to freeze unfertilized oocytes and the ovarian cortex is valuable for genetic resource banking, especially in the case of genetically important individuals that undergo castration or euthanasia for medical reasons. Although offspring have been produced from frozen–thawed oocytes in mice, humans, cattle and rabbits, the results have been variable and not sufficiently successful for routine use. This review provides an overview on the recent knowledge of female germ cell cryopreservation, with a focus on wildlife species, and introduces the Felid Gametes Rescue Project within European Association of Zoos and Aquaria zoos.