Meeting Abstract

86.4  Friday, Jan. 7  Impacts of the mitochondrial-nuclear interaction on metabolic fitness MONTOOTH, Kristi*; HOEKSTRA, Luke; RICE, Jessica; Indiana University, Bloomington; Indiana University, Bloomington; Indiana University, Bloomington montooth@indiana.edu

The mitochondrial-nuclear intergenomic complex plays a foundational role in maintaining metabolic fitness to fuel physiological responses that ectotherms mount in response to the environment. We are using mitochondrial-nuclear hybrids between Drosophila species to better understand the evolutionary processes that shape variation and divergence in the mitochondrial-nuclear genotype and the physiological consequences of this genetic interaction. We are characterizing the metabolic fitness of a mitochondrial-nuclear genetic incompatibility that impacts competitive larval to adult fitness, decreases female fecundity and delays development (Meiklejohn, Rand and Montooth in prep). Mapping of the nuclear and mitochondrial mutations that cause this incompatibility suggests that these hybrids have decreased protein translation in the mitochondria, leading to decreased mitochondrial function. However, we have found that adult metabolic rate is remarkably robust to this energetic disruption. We hypothesize that the severe impact of this mitochondrial-nuclear interaction on development time, fecundity and survival may reflect the cost of maintaining metabolic rate when mitochondrial function is compromised. We will also present data that provide insight into 1) how energetic disruption impacts glycolysis and energy storage and 2) how inducing the heat shock response in these energetically disrupted hybrids impacts metabolic fitness.