Meeting Abstract

P1.99  Friday, Jan. 4  Evolution of energy metabolism in cold-adapted Drosophila melanogaster. CASTELLANOS, L*; SILVERBERG, R; MORGAN, T; WILLIAMS, CM; HAHN, DA; University of Florida, Gainesville; University of Florida, Gainesville; Kansas State University, Manhattan; University of Florida, Gainesville; University of Florida, Gainesville carolinewilliams@ufl.edu

In ectotherms, the time to recovery following cold exposure (chill coma recovery time, CCR) is an ecologically-important phenotype, yet the mechanisms underlying variation in CCR are not well-understood. One hypothesis is that animals showing fast CCR times have higher rates of aerobic metabolism during cold exposure, allowing them to regulate metabolic homeostasis more effectively. This may result in selection to increase rates of metabolism in organisms with greater cold tolerance. We tested this hypothesis using replicate lines of Drosophila melanogaster that have been selected for fast and slow chill coma recovery times, and also in lines originating from a wild-caught population with naturally segregating variation in cold tolerance (the Drosophila Genetic Reference Panel, DGRP), using stop-flow respirometry at a range of temperatures. We present evidence that metabolic rates become elevated as a consequence of selection for fast CCR, and in addition that metabolic rates are positively correlated with CCR times in the DGRP. This is strong evidence that evolution of energy metabolism is an important component of cold adaptation, and has implications for metabolic cold adaptation theory. In addition, we present a novel method of accounting for the influence of activity in stop-flow respirometry.