Daniel Bolnick
Professor, Department of Ecology and Evolutionary Biology; Editor In Chief, The American Naturalist
University of Connecticut Continue Reading Daniel Bolnick
MIDAS Network Member
Paper Information
Title
Between-population differences in constitutive and infection-induced gene expression in threespine stickleback.
Abstract
Vertebrate immunity is a complex system consisting of a mix of constitutive and inducible defenses. Furthermore, host immunity is subject to selective pressure from a range of parasites and pathogens which can produce variation in these defenses across populations. As populations evolve immune responses to parasites, they may adapt via a combination of (i) constitutive differences, (ii) shared inducible responses, or (iii) divergent inducible responses. Here we leverage a powerful natural host-parasite model system (Gasterosteus aculeatus and Schistochephalus solidus) to tease apart the relative contributions of these three types of adaptations to among-population divergence in response to parasites. Gene expression analyses revealed limited evidence of significant divergence in constitutive expression of immune defense, and strong signatures of conserved inducible responses to the parasite. Furthermore, our results highlight a handful of immune-related genes which show divergent inducible responses which may contribute disproportionately to functional differences in infection success or failure. In addition to investigating variation in evolutionary adaptation to parasite selection, we also leverage this unique dataset to improve understanding of cellular mechanisms underlying a putative resistance phenotype (fibrosis). Combined, our results provide a case study in evolutionary immunology showing that a very small number of genes may contribute to genotype differences in infection response.
Journal
Molecular ecology
Citation
MIDAS Authors