Meeting Abstract
Caenorhabditis elegans and other nematodes use a rich “chemical language” that is formed by ascarosides, small molecules with a common carbohydrate core (ascarylose), various fatty-acid-like substituents, and various other substituents such as amino acids, organic acids, or carbohydrates. Hundreds of ascarosides have been identified, but currently only a few have clear functional roles. They are known to be involved in mating behavior, development, dispersal, aggregation, and olfaction; there are likely several other functions that have not yet been characterized. Ascarosides are released into the environment but are synthesized from major primary metabolic pathways. Our working hypothesis is that nematodes sense the environment and modulate metabolic pathways to produce appropriate behaviors. Much of the work on ascarosides has been targeted, either through activity-guided fractionation for biological identification or through targeted mass spectrometry-based assays for chemical identification. We are developing tools that can be used to extract global metabolomic information related to nematode and other organism behavior. I will present a mass spectrometry approach called IROA (isotopic ratio outlier analysis), which allows for the quantitative characterization of hundreds to thousands of small molecules in response to an environmental perturbation. We are also developing approaches using nuclear magnetic resonance (NMR) investigations of isotopically labeled worms to obtain detailed chemical information. These large-scale metabolomic approaches should open up new ways of investigating the chemical interactions of organisms with their environments.
