Skip to main content
2023 ESA Annual Meeting Main banner
Icon Legend
This session is not in your schedule.
This session is in your schedule. Click again to remove it.
Back

Contributed Talk

Session: : Parasitism And Host-Parasite Interactions 4

COS 309-6 - Determining the spatial structure of immune phenotypes in Desert Bighorn Sheep

Thursday, August 10, 2023
4:45 PM – 5:00 PM PDT
Location: D137
Abstract: The long-term resilience of wild ungulate populations in North America requires an understanding of their ability to withstand challenges to their persistence, such as pathogenic infections. Animals in natural habitats typically are host to multiple pathogens at any given time whilst also confronting tradeoffs with life history and habitat quality differences. Why some animals develop acute or chronic infections and others do not is determined by the quality and type of immune response that the host mounts. Immunology must be conceptualized in an ecological framework to examine these questions in a wild context. Understanding population level patterns in immunological function can help managers identify populations and individuals at risk of disease invasion. Desert bighorn sheep (Ovis canadensis nelsoni, DBH). occupy large, yet relatively discrete mountain ranges throughout the deserts of California, allowing the possibility to investigate how host immune responses may structure spatially, given that populations have different disease exposures and genetic connectivity. We measured immune functions of greater than 500 wild DBH individuals employing 13 different assays. These assays characterized various components of an immune response, including both innate and adaptive responses to bacterial and mitogenic challenge as well as a-priori states of immunity. Measurements included blood chemistry analysis, differential blood cell counts, lymphocyte proliferation, analysis of 6 different pro and anti-inflammatory cytokines, and bacterial killing ability amongst others. The data from the corresponding results was used to defined immune phenotypes of DBH in relation to functional measures. We then investigated if these phenotypic differences are structured spatially in the population and found differences across space in terms of adaptive immune traits such as lymphocyte proliferation. This immune toolkit establishes a methodology that can be utilized to understand immune response patterns in other populations of bighorn sheep, comparative studies with other sheep species, including domestic sheep (Ovis aries), and fine-tuned for other wild ungulate species in future studies of disease ecology and ecoimmunology.