A metabonomic analysis of insect development: 1H-NMR spectroscopic characterization of changes in the composition of the haemolymph of larvae and pupae of the tobacco hornworm, Manduca sexta

The analysis of complex biological samples, principally biological fluids, to obtain global metabolite profiles using techniques such as high resolution NMR spectroscopy has been termed metabonomics. This work describes the application of metabonomics to characterize the biochemical changes associated with development during the various instars of the larval stages and in the pupal stage of the tobacco hornworm Manduca sexta. The levels of many small molecule metabolites change during development. Thus, alanine, glutamate, lysine, succinate, lactate, and betaine are present at relatively high levels during the feeding period of larval life, but decrease at the onset of wandering. Compounds that increase in concentration as the insects prepare to pupate include citrate, fatty acids, and succinate. The presence of variable levels of putrescine in haemolymph is interesting, given its possible role in juvenile hormone action. The potential of high resolution H-1-NMR spectroscopy for the metabonomic analysis of insect developmental chemistry is discussed.