Development of Optimal Methods for Cryopreserving Sperm in a Variety of Species
An ongoing project conducted opportunistically upon the death of an animal or with semen collected during a routine medical examination. It is important to note that, as with tigers, wild or domestic animal counterparts do not always serve as model species for determining what treatment regimen should be used for freezing sperm. Each species often requires refinement or modifications of existing protocols to be optimal for cryobanking semen.
Embryo Production by In-Vitro Oocyte Maturation, Fertilization and Culture and In-Vitro-Derived Embryo Cryopreservation in Domestic Cattle
These procedures are used as quality controls for the CCR In Vitro Fertilization Laboratory as well as for training of new students and personnel in the proper handling and processing of mammalian oocytes and the in-vitro production of embryos. Since unfertilized oocytes can not be frozen in practically all species, it is necessary to produce embryos by in vitro fertilization since these generally can survive freezing and thawing.
Cryopreservation and Culture of Ovarian Tissue
In light of the fact that unfertilized oocytes can not be cryopreserved very successfully in any species, researchers have demonstrated in humans and laboratory animals that ovarian tissue may be a more effective means of salvaging gametes from females after ovariectomy or death. The tissues are frozen then thawed and cultured until the ovarian follicles grow to a point that oocytes can be recovered and fertilized to produce viable embryos. These same procedures are being tested by the staff and students of the CCR Reproductive Sciences Department on model species such as domestic cats and cows, with the intention of eventually applying effective methods to their endangered species counterparts. Below is an electron micrograph of a domestic cat ovarian follicle containing a maturing oocyte.
Omaha's Henry Doorly Zoo and Aquarium's CCR Genome Resource Bank
Currently, over 20,000 individual samples of sperm and embryos from over 40 species are in liquid nitrogen storage and monitored by a state-of-the-art computerized system.