Presentation Type

Poster

Presenter Information

Natassia P. Watson, USFFollow

Title of Abstract

EXAMINING THE COST OF RESISTANCE AND TOLERANCE THROUGH DOSES RESPONSE AND RESOURCE RESTRICTION

Abstract

In the presence of an infectious agent, organisms can respond by either reducing their parasitic burden (resistance) or limiting the damage caused by a parasite (tolerance). Disentangling the difference between resistance and tolerance in animals is a challenging feat that remains unaccomplished partly due to the need for well-designed experiments that can lend themselves to more meaningful statistical analyses. Trematodes are common parasites of amphibians that are useful in the study of resistance and tolerance. We sought to determine if there was variation in tadpole resistance and tolerance as function of both trematode exposure and available resources. We did so using a dose-response approach in which different levels of parasite exposures were crossed with different levels of available resources in a full factorial design. We also examined whether there were any differences in resistance and tolerance between tadpoles that were resource restricted before or after being exposed to parasites. Applying linear regression analysis to these results, we show that change in tadpole mass as a function of resource levels was dependent on the level of parasite exposure, but only when the tadpoles were resource restricted before parasite exposure. This suggests that amphibian condition before trematode exposure is more influential to the fitness consequences of trematode infections than amphibian condition after infection establishment. Body condition was not significantly affected by the treatments, and we await further results regarding effects of the treatments on development and the proportion of parasites that successfully infected the tadpoles. These findings could therefore have useful applications in conservation and management efforts that seek to assess the suitability of amphibian habitats and/or determine ways in which to improve amphibian health.

Categories

Natural Sciences

Research Type

Thesis

Mentor Information

Dr. Jason Rohr

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EXAMINING THE COST OF RESISTANCE AND TOLERANCE THROUGH DOSES RESPONSE AND RESOURCE RESTRICTION

In the presence of an infectious agent, organisms can respond by either reducing their parasitic burden (resistance) or limiting the damage caused by a parasite (tolerance). Disentangling the difference between resistance and tolerance in animals is a challenging feat that remains unaccomplished partly due to the need for well-designed experiments that can lend themselves to more meaningful statistical analyses. Trematodes are common parasites of amphibians that are useful in the study of resistance and tolerance. We sought to determine if there was variation in tadpole resistance and tolerance as function of both trematode exposure and available resources. We did so using a dose-response approach in which different levels of parasite exposures were crossed with different levels of available resources in a full factorial design. We also examined whether there were any differences in resistance and tolerance between tadpoles that were resource restricted before or after being exposed to parasites. Applying linear regression analysis to these results, we show that change in tadpole mass as a function of resource levels was dependent on the level of parasite exposure, but only when the tadpoles were resource restricted before parasite exposure. This suggests that amphibian condition before trematode exposure is more influential to the fitness consequences of trematode infections than amphibian condition after infection establishment. Body condition was not significantly affected by the treatments, and we await further results regarding effects of the treatments on development and the proportion of parasites that successfully infected the tadpoles. These findings could therefore have useful applications in conservation and management efforts that seek to assess the suitability of amphibian habitats and/or determine ways in which to improve amphibian health.