Mask, Tracy Ann, authorBruemmer, Jason, advisorBouma, Gerrit, committee memberKane, Albert, committee memberRansom, Jason, committee member2007-01-032007-01-032014http://hdl.handle.net/10217/83998Immunocontraception with the porcine zona pellucida (pZP) antigen is a well-published means of wild horse contraception. There are three pZP vaccines currently proposed for use in horses, Zonastat-H®, PZP-22, and SpayVac®. Despite abundant research concerning the safety and contraceptive efficacy of pZP vaccines in numerous species, the contraceptive mechanisms of the pZP antigen remain unclear and have not been investigated thoroughly for SpayVac. We investigated the immunoreactivity of anti pZP antibodies from the serum of SpayVac vaccinated mares to equine zona protein using Western blot and immunohistochemical techniques. These techniques were first applied using a bovine model because bovine oocytes are more easily obtained in large quantities relative to equine oocytes. Once the procedure was validated, equine samples were utilized. Western blot analysis revealed immunoreactivity of anti pZP antibodies that were produced in response to SpayVac vaccination to protein isolated from mature equine oocytes, equine zona pellucidae, equine follicular tissue, and equine ovarian stromal tissue. Immunohistochemical analysis identified the location of binding of anti pZP antibodies to the zona pellucida of mature oocytes isolated from Graafian follicles as well as the zona pellucida of immature oocytes in ovarian tissue. Western blot and immunohistochemical analyses also indicate high specificity of anti pZP antibodies for equine zona protein and predominant affinity for zona protein 3. Collectively, results suggest a model where anti pZP antibodies produced in response to SpayVac vaccination are immunoreactive to equine zona protein in vitro. If available in the follicular fluid and able to permeate the ovary following SpayVac vaccination, anti pZP antibodies may act on not only mature oocytes, but also oocytes of growing follicles in vivo. The results of this study lend insight into the infertility observed following SpayVac vaccination, and may also help explain the long-term ovarian effects following pZP vaccination reported by other studies.born digitalmasters thesesengCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.SpayVacequus caballusanti pZP antibodiespZPText