Meeting Abstract
The physiological responses of organisms to short-term environmental stress, such as infection, can have long-term consequences for fitness, particularly if responses are inappropriate or nutrient resources are limited. Physiological responses to pathogens in the environment can be energetically costly, drawing on energy resources that would otherwise be devoted to organismal growth, maintenance, and reproduction. This energy balance can generate life-history tradeoffs that may shift through development and are likely influenced by external factors such as infection, environmental changes, and resource availability. While the pathways of immune responses are well-characterized, how organismal responses to infection are impacted by energy limitation is not well understood. Yet, the pathways that mediate innate immune responses and that respond to nutrient availability are connected. Here I use well-characterized mitochondrial-nuclear genotypes of the fruit fly, Drosophila melanogaster, that have compromised aerobic energy metabolism to test for effects of compromised energy metabolism on infection and life-history traits using a natural bacterial pathogen. My results demonstrate that adult survivorship post infection is significantly decreased in energetically compromised genotypes relative to wildtype controls, but only in females. However, energetically compromised individuals that survive infection produce a similar number and quality of offspring relative to uninfected individuals. Thus, while females do show expected phenotypes of compromised energy metabolism on the ability to fight infection, the effects on the future reproduction of females surviving infection are minimal when provided optimal resources during adulthood.
