Parasites are an important component in the ecosystem, and have important consequences on human and animal health. Parasites have deleterious effects on host reproductive success and thus impose strong selection pressures on hosts for reduced susceptibility or complete resistance to infection. However, there is often considerable variation in susceptibility to parasite infection among individuals within a population. One important constraint on the evolution of resistance is genetic tradeoffs between resistance and host fitness. This project will use the association between a rat tapeworm parasite (Hymenolepis diminuta) and its intermediate host, the red flour beetle (Tribolium castaneum) to identify the candidate resistance genes using map-based cloning and bioinformatics techniques, to test the function of these candidate genes on resistance, and to determine the genetic tradeoffs between resistance and host fitness. In the first-year award, we will establish the parent RNAi method, a technique critical for testing the function of candidate genes on resistance and fitness.
The project has broader implications for vector-borne disease control and conservation. The idea of using genetic engineering to introduce parasite-resistance genes into natural mosquito populations to control malaria, Dengue, or filarial worms has been in discussion. The issue of resistance evolution is particularly relevant for the development of novel strategies to spread parasite-resistance genes into natural vector populations. The materials, methodologies, and research results to be developed by the project will be integrated into the university courses and workshops.
