Eco Immunology of laboratory adapted Drosophila melanogaster populations

Abstract

At the heart of eco-immunology lies the observation that host populations newlineexhibit a high degree of variability in terms of resistance to pathogens and parasites. A newlinesignificant portion of this variability can be attributed to the genetic variation within the host newlineand the pathogen populations, but even after accounting for such genetic variation, not all the newlinevariability in resistance can be explained away. Therefore, it has been argued that variability newlinein resistance to pathogens and parasites can stem from environmental and other sources, such newlineas previous experience with pathogens and reproduction-immunity trade-offs. To explore such newlinenon-genetic factors that determine host resistance to infections, I studied the effects of bacterial newlineinfections on the fitness of fruit flies (Drosophila melanogaster) in terms of survival and newlinereproductive output, and what factors either intrinsic (age and mating status) or extrinsic newline(resource availability and parental exposure to pathogens) modify these effects. newlineFirst, I demonstrated that resource limitation (via concurrent starvation and/or sexual activity newlineinduced systemic resource allocation) increases host susceptibility to bacterial infections in a newline