Meeting Abstract
Host-parasite interactions are poorly understood, despite their effects on a range of ecological and evolutionary processes. Specifically, variation in host resistance and the evolution of this resistance is well studied from a theoretical standpoint, but understanding of associated cellular mechanisms is lacking. The three-spined stickleback, Gasterosteus aculeatus, is a particularly powerful model of the evolution of host resistance: populations of G. aculeatus vary considerably in their resistance to the cestode parasite, Schistocephalus solidus. Using transcriptional analyses of experimental infections, we investigated patterns of gene expression that underlay host-parasite dynamics and contribute to variation in host immune response. We examined general host response to infection and compared gene expression across three different cross types (F2s and respective backcrosses) generated from two populations of fish, one resistant and one susceptible. Our findings indicate that infection is associated with suppression of host immunity. Resistant populations may circumvent this suppression. Furthermore, comparison of crosses allowed for the identification of candidate genes that may contribute to observed resistance phenotypes. These findings advance our understanding of the dynamics and evolution of host-parasite interactions in the G. aculeatus– S. solidus system. Broadly, the findings presented here are an excellent case study of micro-evolution of immune responses within a population, and contribute to increased understanding of evolutionary immunology and host-parasite coevolutionary dynamics.
