Optimization of In Vitro Culture Requirements for Gamete Manipulation

Germplasm preservation is now recommended by virtually all Species Survival Plans and Taxon Advisory Groups as a means to maintain long-term genetic diversity. However, a repository is of little value if the germplasm stored within is not capable of producing offspring when thawed. The primary source of gametes in the Frozen Zoo® at CRES is postmortem harvest of immature sperm and ova directly from excised gonads. Thus, even with optimal cryopreservation, sperm and ova must survive extensive in vitro manipulation prior to use in assisted reproduction for the creation of offspring.

The objectives of this project include the development of in vitro oocyte maturation, sperm capacitation, fertilization (including intercytoplasmic sperm injection), and embryo culture techniques for fresh and cryopreserved germplasm. The domestic dog will serve as a carnivore model with gonads from local veterinary clinics. Protocols developed for domestic cattle will form the basis for in vitro techniques for gametes collected from postmortem bovids from the San Diego Zoo and the San Diego Zoo's Wild Animal Park.