Meeting Abstract

P2.100  Friday, Jan. 4  The U-shaped Metabolic Curve of Insect Metamorphosis: Substrate Utilization Patterns and Proximate Causes MERKEY, Allison B*; GIBBS, Allen G; HOSHIZAKI, Deborah K; Universityof Nevada, Las Vegas; University of Nevada, Las Vegas; University of Nevada, Las Vegas merkeya@unlv.nevada.edu

We have previously demonstrated that metamorphosing pupae of Drosophila melanogaster exhibit the standard U-shaped curve for metabolic rate, where metabolism decreases dramatically after pupariation and increases shortly before eclosion. In this study, we demonstrate that total energy requirements during metamorphosis are inversely related to temperature, primarily because differences in developmental time offset the effects of temperature on metabolic rate. Interestingly, pupae consumed more triglycerides over the course of development at low temperatures and more carbohydrates at high temperatures. We also tested the hypothesis that pupae become oxygen-limited during the re-modeling of the tracheal system, thereby causing the metabolic rate changes during metamorphosis. We found that carbon dioxide production by pupae was unaffected by atmospheric oxygen levels from 5 to 40%. Pupae did not accumulate lactate under normoxic conditions, although they are capable of anaerobic metabolism, as shown by significant lactate accumulation during hypoxia. Thus, oxygen limitation does not cause the U-shaped metabolic pattern. Supported by NSF awards IOS-0719551 to DKH and IOB-0514402 to AGG.