A cytosolic Superoxide dismutase mutant allele and its metabolism: Investigating the metabolic profile of a mutant fly using Liquid Chromatography - Mass Spectrometry. Jose M. Knee¹, Teresa Rzezniczak¹, Kevin Guo², Thomas Merritt¹. 1) Chemistry & Biochemistry Department, Laurentian University, Sudbury, Ontario, Canada; 2) Bruker Daltonics Inc., Billerica, MA.

   We use liquid chromatography-mass spectrometry (LC-MS) to describe and quantify the impact of knocking out the superoxide dismutase gene in Drosophila melanogaster. Further we compare this metabolomic fingerprint with that of chemically-induced oxidative stress to test the hypothesis that Sod null mutants exist in a state of chronic oxidative stress. LC-MS analysis can detect and quantify a broad array of small molecule metabolites and is quickly developing into a powerful tool for researchers in all fields of the life sciences. We have developed a general protocol to quantify the metabolome and assessed the applicability of this technique to D. melanogaster by comparing a Sod1 null mutation line with a transgenic control under benign conditions and under paraquat exposure. The SOD1 protein is involved in reactive oxygen species scavenging and Sod1 mutants accumulate both ROS and products of ROS damage. Paraquat induces oxidative stress by chemical production of the superoxide ion. By evaluating the levels of a large set of metabolites, it was determined that over 100 metabolites were present at a significantly different level between the nulls and the controls. The LC-MS protocol used in this study not only aids in understanding the metabolic consequence of a Sod1 mutation and oxidative stress, but also highlights the applicability of LC-MS analysis to future studies using different systems.