Investigating the role of UV-light in volatile pheromone production of Drosophila melanogaster

Sammanfattning

Insects produce an epicuticle comprised of a complex mixture of hydrocarbons and closely related chemical compounds, originally evolved as a mechanism to prevent desiccation but which developed an additional role as a form of chemical fingerprint unique to the species in question. This is useful as both intra- and interspecific communication, however the low volatility of these hydrocarbons permits only short-range communication. One cuticular hydrocarbon produced by Drosophila melanogaster females is (Z,Z)-7,11-heptacosadiene, may be spontaneously oxidized at its double bonds. One possible oxidation product is (Z)-4-undecenal, which has recently been shown to function as a long-range pheromone owing to its higher volatility as compared to its hydrocarbon precursor. The aim of this study is to investigate the effects on (Z)-4-undecenal production by ultraviolet light. This involves investigating different sampling durations of (Z)-4-undecenal, as well as irradiating both synthetic (Z,Z)-7,11-heptacosadiene and live D. melanogaster females. Headspace collection is done through solid phase microextraction, and subsequent analysis with gas chromatography-mass spectrometry. Due to the variability in the results, it was not possible to verify the hypothesis that ultraviolet light increases production of (Z)-4-undecenal in D. melanogaster, however the study did provide insights as to which experimental parameters could be modified in future research. Some suggestions are provided.