Meeting Abstract
Mitochondria require both mitochondrial- and nuclear-encoded genes to provide the energy for eukaryotic development and performance. It is therefore not surprising that selection on mitochondrial function shapes the evolution of both mitochondrial and nuclear genomes. Given its central role in the energy budget of eukaryotic organisms, there is reason to expect that variation in mitochondrial function will contribute to the evolution of life-history traits. Furthermore, to the extent that limiting resources can generate tradeoffs between life-history traits, defects in mitochondrial function that limit energy stores may reveal life-history tradeoffs even when nutrient resources in the environment are not limiting. We review the literature for mitochondrial effects on immune function, and present evidence that defects in oxidative phosphorylation caused by mitochondrial-nuclear incompatibility compromise immune function and generate tradeoffs between immunity and fecundity in Drosophilid flies. Given the unique genetics and biology of mitochondria, we also expect that gene-environment and gene-gene (i.e., epistatic) interactions will govern genotype-phenotype relationships for traits that depend upon mitochondrial function. We review the evidence that mitochondrial effects on life-history traits are complex and involve mitochondrial-nuclear epistasis, environmental sensitivity, and life-stage, sex and tissue specificity. Finally, we discuss the impact of complex mitochondrial genotype-phenotype relationships on mitochondrial evolution, as well as implications for investigations in eco-immunology.
