Ce travail a consisté en l'étude de protéines de spermatozoïdes de différentes, avec l'objectif de contrôler leur pouvoir fécondant. Dans un premier temps une protéine antioxydante du tractus génital mâle, et acquise au cours de la maturation épididymaire, la glutathion peroxydase 5 (GPX5), a été étudiée dans deux espèces d'intérêt agronomique : l'étalon et le taureau. Les semences de ces animaux sont fréquemment conservées pour des inséminations artificielles. Or lors de la conservation, les spermatozoïdes subissent entre autres un stress oxydant. L'ajout de cette protéine antioxydante dans le milieu de conservation pourrait limiter les dommages subis par les spermatozoïdes. Les séquences spécifiques de cette protéine dans chaque espèce ont été obtenues. Les ARNm ont ensuite été localisés dans les canaux efférents et la tête de l'épididyme équine, ainsi que dans la tête et le corps de l'epididyme bovin. Par ailleurs la protéine bovine a été localisée dans la tête et le corps epididymaire. La seconde partie de ce travail a consisté a analyser les antigènes spermatiques spécifiques d'un rongeur fouisseur , le campagnol terrestre Arvicola terrestris Scherman dans le but de les utiliser pour une immunocontraception de cet animal nuisible. La détermination de protéines spermatiques suscepyibles d'être immunogènes a été entreprise.

White-tailed deer (Odocoileus virginianus) numbers on the National Aeronautics and Space Administration's (NASA) Johnson Space Center (JSC) in Houston, Texas have increased in recent years and are a cause of urban-related accidents (e.g., deer-vehicle collisions, negative interation with humans). Safety personnel for the JSC are interested in reducing human-deer interaction by a reduction in overall population numbers. My overall study objectives were to (1) estimate population parameters for JSC deer, (2) develop a computer simulation model for the JSC deer, and (3) evaluate 2 management strategies to control JSC deer numbers a priori using the JSC deer model. The 2 management strategies I evaluated were the efficacy of SpayVac immunocontraceptive vaccine (sterilization) and trap and translocation (deer removal) efforts in managing white-tailed deer on JSC. In general, single treatments of removals or sterilization (less than 75 percent of female deer treated) were not effective in reducing population growth (R greater than 1). Approximately 50% of female deer needed to be removed annually to reduce population growth whereas approximately 25% of female deer needed to be treated annually with SpayVac for the same effects. A combination of trap and removals and sterilizations was effective in reducing population growth when applied to approximately 25% of the female population annually. I recommend the use of sterilization annually (25%) or a combination of sterilization and removal (25%) to achieve the goals of JSC in maintaining current deer numbers. Removing or sterilizing > 50% of the female deer annually caused the JSC deer population to decrease to a level near eradication.

White-tailed deer (Odocoileus virginianus) numbers on the National Aeronautics and Space Administration's (NASA) Johnson Space Center (JSC) in Houston, Texas have increased in recent years and are a cause of urban-related accidents (e.g., deer-vehicle collisions, negative interation with humans). Safety personnel for the JSC are interested in reducing human-deer interaction by a reduction in overall population numbers. My overall study objectives were to (1) estimate population parameters for JSC deer, (2) develop a computer simulation model for the JSC deer, and (3) evaluate 2 management strategies to control JSC deer numbers a priori using the JSC deer model. The 2 management strategies I evaluated were the efficacy of SpayVac immunocontraceptive vaccine (sterilization) and trap and translocation (deer removal) efforts in managing white-tailed deer on JSC. In general, single treatments of removals or sterilization (less than 75 percent of female deer treated) were not effective in reducing population growth (R greater than 1). Approximately 50% of female deer needed to be removed annually to reduce population growth whereas approximately 25% of female deer needed to be treated annually with SpayVac for the same effects. A combination of trap and removals and sterilizations was effective in reducing population growth when applied to approximately 25% of the female population annually. I recommend the use of sterilization annually (25%) or a combination of sterilization and removal (25%) to achieve the goals of JSC in maintaining current deer numbers. Removing or sterilizing > 50% of the female deer annually caused the JSC deer population to decrease to a level near eradication.

Feral swine are a nuisance species across the United States that costs around $1.5 billion each year in agricultural, environmental, and personal property damages. In the last ten years the population of feral swine is estimated to have quadrupled and novel population control methods are needed. Furthermore, feral swine are known carriers of zoonotic diseases such as brucellosis, which threatens both livestock biosecurity and public health. Recombinant multimeric gonadotropin-releasing hormone (mGnRH) has been previously used as a subunit vaccine to induce immunocontraception in feral pigs. However, potent adjuvants and large amounts of purified antigen are needed to elicit a robust anti-GnRH immune response and current delivery methods are limited. Brucella suis strain VTRS2 can be used as a novel platform to deliver mGnRH without the use of antibiotic resistant markers. Strain VTRS2 was created by deletion of the LPS biosynthesis gene wboA as well as the leuB gene required for leucine biosynthesis inside the nutrient-depleted intracellular environment occupied by Brucella. Mutations in wboA are known to attenuate Brucella strains such as the vaccine strain B. abortus RB51, however strain RB51 is rifampin resistant and has poor efficacy in swine. Strain VTRS2 confers significant protection against B. suis challenge in mice and additionally shows evidence of protection in feral swine. Furthermore, the mGnRH antigen can be delivered using the pNS4 plasmid (which expresses leuB under its native promoter) thus maintaining the plasmid in strain VTRS2 under leucine-deficient conditions while expressing recombinant antigen in the host. The murine model was used to determine the clearance kinetics of strain VTRS2-mGnRH and to measure vaccine efficacy against challenge by virulent B. suis 1330. Subsequently the effects of the VTRS2-mGnRH vaccine on fertility were assessed in breeding trials in mice. Strains VTRS2 and VTRS2-mGnRH were found to be protective against virulent Brucella suis challenge. Strain VTRS2-mGnRH elicited an anti-mGnRH antibody response in vaccinated mice, though an effect on fertility was not observed. An improved vaccine against brucellosis in swine, which also confers immunocontraception without the introduction of antibiotic resistance, could become an important tool in the management of this nuisance invasive species. / Ph. D.

Mammal species often live in social groups, but the factors that promote group cohesion can be difficult to analyze due to the prevalence of strong group affiliations. Feral horses maintain stable harems of one or two males and several females, and harem stability is strongly related to individual fitness. Anecdotal evidence and an early study in the non-breeding season suggest that management of the Shackleford Banks island horses with immunocontraception reduces harem stability in the population, providing an opportunity to study the factors that influence harem stability. I investigated the effects of the immunocontraceptive PZP on harem stability during the breeding season and examined mare activity budgets and harassment rates to determine if these factors influence harem stability. I hypothesized that 1) immunocontraception would increase the rates at which mares changed harems during the breeding season 2) activity budgets of contracepted individuals would differ significantly from those of uncontracepted individuals, and 3) contracepted mares would experience greater levels of harassment associated with changing harems than uncontracepted mares. I found that the immunocontraceptive does increase harem changes during the breeding season. I also found that contracepted mares have different activity budgets than uncontracepted mares; as predicted, contracepted mares grazed less and moved more than uncontracepted controls. The factors that influence mare activity budgets included immunocontraception, harem stallion, number of individuals in the harem, number of mares in the harem and body condition of the mare, as well as some interactions between factors. I found that high harassment rates by both harem stallions and other mares in the harem are correlated with higher harem change rates and that contracepted mares are harassed more than uncontracepted mares. These results indicate that the immunocontraceptive does influence harem stability in this feral horse population, potentially through alterations in activity budgets and harassment rates.

With approximately 8.5 million unwanted cats euthanized in the U.S. annually, convenient, cost effective methods of sterilization are greatly needed. Current spay/neuter techniques, such as surgery and hormonal intervention, are not satisfying this need due to their high cost, significant expertise required, and the need for feral cats to be collected and brought into clinics for treatment. The aim of this research is to develop a safe contraceptive vaccine that could be delivered to the feral cat population in bait without compromising non-feline species. Feline Herpes Virus (FHV) is a feline specific virus. The USDA has approved the immunization of cats with an attenuated, non-pathogenic strain of FHV expressing foreign antigens. In our research, we have partially replaced Glycoprotein I of FHV to express a fusion protein of Flagellin (FliC), Enhanced Green Fluorescent Protein (EGFP), and Gonadotropin Releasing Hormone (GnRH). FliC has been shown to stimulate a heightened antibody response when antigens are expressed as fusion proteins with it. GnRH, a major reproductive hormone responsible for the development of testes and ovaries in felines, is the target of our vaccine vector. Expression of EGFP will allow tracking of the viral vector. The expression of the fusion protein (FliC-EGFP-GnRH) is expected to stimulate an antibody and cell mediated immune response directed towards feline GnRH, which will provide an immunocontraceptive effect specific to cats. / Master of Science