The Tiger Project has been a long-term program of the Reproductive Sciences Department that has focuses on all aspects of assisted reproductive technology including artificial insemination, semen freezing, in vitro embryo production (including fertilization by intracytoplasmic sperm injection), freezing and transfer, and the production of tiger-specific hormones for stimulating and synchronizing ovarian activity in tigers.
In-Vitro Embryo Production and Cryopreservation in Siberian Tigers
Studies have been conducted to test the effectiveness of pig (porcine) gonadotropins for repeatedly stimulating ovarian activity (follicle growth for oocyte or egg collection) in tigers. The porcine hormones are the most similar product commercially available. Sperm and in vitro produced tiger embryo procedures have been successful, however, pregnancy rates have been less than satisfactory using the porcine hormones to synchronize ovarian cycles. The success of the treatments are being examined by measuring reproductive hormone metabolites in the feces of the tigers.
Determining the Efficacy of a GnRH Implant for Performing Assisted Reproductive Techniques in Tigers
A continuation of previous laparoscopic assisted reproduction studies in tigers. In this case we want to laparoscope the tigers when they are in natural heats, artificially inseminate them and implant a synthetic hormone implant (deslorelin) to induce ovulation.
Sequencing Tiger-Specific Gonadotropins (specifically LH)
For use in ovarian stimulation and synchronization for cat embryo transfer. This project is a collaboration with the University of Nebraska Medical Center's Eppley Institute. Sequencing of the DNA section coding for tiger FSH and LH has been completed and transfection of cat kidney and Chinese hamster ovary cell lines is accomplished. Current efforts focus on propagation and testing of various cell line strains to find the most productive ones. The product will be collected in culture medium and concentrated by lyophilization will be tested for bioactivity in domestic cats.
Development of Novel and More Effective Techniques for Freezing (Vitrifying) Cat Embryos as a Model for Exotic Felids
Traditional methods for cryopreserving (freezing) embryos from livestock or humans can work with domestic cat embryos, but do not necessarily work for exotic felids such as tigers. A more recent technique, called vitrification, was found to be most effective for freezing cleavage stage embryos from in-vitro produced tiger embryos with an approximately 50% survival rate post-thawing.