Costs of Resistance in a Natural Host-parasite System

University Of Cincinnati Main Campus, Cincinnati OH

Investigators

Abstract

We know very little about the magnitude of genetic variation underlying parasite resistance, or about the mechanisms responsible for the maintenance of this variation. This lack of information limits our ability to predict the evolution of both host resistance and parasite virulence. This research seeks to understand the source of genetic variation underlying resistance against parasitism, and hence the evolutionary potential of this key ecological trait. Experiments will test whether genetic resistance is associated with fitness costs to the host in the absence of parasitism. The animal system to be employed is the Sonoran Desert endemic Drosophila-Macrocheles mite association. The approach will consist of generating behaviorally resistant genetic lines of the host by artificial selection in the laboratory, followed by contrasting resistant versus susceptible lines in terms of a broad spectrum of juvenile and adult fitness traits under variable levels of environmental stress. The results will contribute basic knowledge toward implementing sustainable biological control of pest species, and hence they will be of significant practical, societal and economic value. The work addresses how environmental change, often seen on a global scale, affects levels of parasitism by ectoparasitic arthropods, many of which are known vectors of transmissible parasitic disease. The research will thus inform wildlife epidemiology, conservation biology, and medical and veterinary research into the causes of emerging animal epidemics.