Meeting Abstract

123.2  Monday, Jan. 7  Selection for cold tolerance alters the maintenance of metabolic homeostasis during cold exposure in Drosophila melanogaster. WILLIAMS, CM*; WATANABE, M; MORGAN, T; EDISON, AS; BOROUJERDI, A; HAHN, DA; University of Florida, Gainesville; Claflin University, Orangeburg; Kansas State University, Manhattan; University of Florida, Gainesville; Claflin University, Orangeburg; University of Florida, Gainesville carolinewilliams@ufl.edu

Low temperatures induce in insects a state of paralysis (chill coma), which is reversible following the return of favourable conditions, although the time taken to recover varies widely both inter- and intra-specifically. This variation may result from differences in the degree to which insects can maintain metabolic homeostasis during cold exposure. We selected replicate lines of Drosophila melanogaster for either fast or slow recovery from chill coma (cold-tolerant or -susceptible lines), then profiled and compared the polar metabolome before, during and after cold exposure using nuclear magnetic resonance spectroscopy. We found that the cold tolerant lines were smaller, and maintained a higher degree of metabolic homeostasis during cold exposure. Pathways that responded differently to the cold exposure between cold-tolerant and –susceptible lines included amino-acyl tRNA biosynthesis (indicating differential levels of translation during cold stress), proline and alanine metabolism, starch and sucrose metabolism, and the TCA cycle. Our results suggest that adaptation to cold environments results in evolution towards energetic pathways that function better in the cold. These lines are fully genotyped, allowing us to look for genetic divergence in implicated pathways among the selected lines.