Identification and Synthesis of D. athabasca Cuticular Hydrocarbons

Abstract

We are investigating the role of chemical signals on courtship behavior of Drosophila. The chemical signals of Drosophila athabasca are cuticular hydrocarbons, derived from fatty acids, spanning 20‐40 carbons in length with variations in saturation and branching patterns. Drosophila athabasca has three distinct races that are geographically overlapping but reproductively isolated: WestNorthern, Eastern A, and Eastern B. We have identified several pheromones of Drosophila athabasca that may influence the sexual selection that necessarily precedes speciation. Using Gas Chromatography tandem Mass Spectrometry and dimethyl disulfide derivatization (DMDS), we have characterized the pheromone composition of several isofemale lines. Synthesis of the major pheromones was completed to confirm identity of the cuticular hydrocarbons. Synthesis of monounsaturated hydrocarbons utilized cis‐directed Wittig reactions, while diene hydrocarbon synthesis employed substitution chemistry with acetylenes followed by a cis‐selective reduction. Purification and isomeric separations of hydrocarbons was completed using silica followed by argentation chromatography. Behavioral studies using synthetic pheromones are underway and may provide insight into the relationship between cuticular hydrocarbons and mate discrimination.