PARENT SESSION
Oral Session 14: Reptiles and Amphibians I: Salamanders and Newts.
Presiding: K McCoy
Monday, August 2, 8:00 AM to 11:30 AM, Meeting Room D 136.
Large-scale differences in disease susceptibility in an amphibian-virus system.
Schock, Danna*,1, Bollinger, Trent2, Collins, James1, 1 Arizona State University, Tempe, Arizona, USA2 Canadian Cooperative Wildlife Health Centre, Saskatoon, Saskatchewan, Canada
ABSTRACT- Infectious diseases play essential roles in the ecology and evolution of all life. While the eclectic and burgeoning literature on host-pathogen biology attests to widespread interest within the scientific community, the need to understand host-pathogen relationships well enough to manage their effects has taken on renewed urgency as infectious diseases emerge, or in some cases, re-merge, as major threats to human and wildlife populations. Identifying patterns of host susceptibility and elucidating the factors responsible for those patterns are key to understanding what precipitates disease outbreaks and how to manage the effects. Our research focuses on understanding factors that can generate population-level differences in host susceptibility to infectious diseases. Our system is the tiger salamander (Ambystoma tigrinum) and a group of closely-related lethal salamander viruses. Multi-year laboratory and field studies have revealed predictable large-scale differences in disease susceptibility and severity among tiger salamander populations in Saskatchewan and Manitoba, Canada. Several mechanisms could potentially generate such patterns so we have focussed on testing three likely mechanisms. We are testing whether there are differences in exposure to immuno-suppressive chemical contaminants, differences in host population structure, or differences in genetic diversity that explain the differences in disease susceptibility. Although exposure to chemical contaminants is an obvious candidate, we have found no evidence in support of this hypothesis. Rather, several lines of evidence suggest that differences in tiger salamander population structure and genetics may be generating this pattern, indicating that factors intrinsic to the salamander-virus relationship are generating the observed patterns in host susceptibility.
Key words: evolutionary ecology, disease ecology, population genetics