|
Principal Investigator: Alexander Travis
Contact Information: E-mail: ajt32@cornell.edu - Phone: 607-256-5613
Sponsor: Morris Animal Foundation
Grant Number: D07ZO-097
Title: Analyzing the Function of Feline Sperm Produced by Testis Xenografting
Annual Direct Cost: $49,500
Project Period: 09/01/07-08/31/09
DESCRIPTION (provided by applicant): Loss of genetic diversity due to infertility or the premature death of valuable individuals is a significant problem in the conservation of rare/endangered species of cat. Attempts to overcome this loss of genetic information in males have focused on freezing sperm; however, sperm cannot be collected from young prior to reproductive maturity. We have shown that “testis xenografting” provides a method to produce sperm using donor tissue from cats aged between neonates to those just entering puberty. This method involves the grafting of small pieces of testis into immunodeficient mice, where the xenografts will grow and produce sperm. To be useful for conservation, we must demonstrate that these xenograft-derived sperm are functional. Preliminary experiments using xenograft-derived sperm collected at 50 weeks post-implantation revealed cleavage, but no embryonic development to blastocysts. This timepoint for retrieval maximized our chance of recovering sperm to assess effective donor age range; however, the sperm were likely retained in the grafts too long and started to degrade. Based on the appearance of spermatids at the 30 week timepoint, we hypothesize that collection between 33-45 weeks will result in the retrieval of functional sperm. In this proposal, we outline a series of experiments to test the developmental competency of the xenograft-derived sperm. We shall collect sperm and perform intra-cytoplasmic sperm injection, assessing early embryo development in vitro. If normal, we shall proceed to embryo transfer. Finally, should live young be produced, we shall then begin to evaluate their health status and behavior versus controls.
|
