Drosophila melanogaster prefers compounds perceived sweet by humans. Chemical Senses 33

To understand the functional similarities of fly and mammalian taste receptors, we used a top–down approach that first estab-lished the fly sweetener–response profile. We employed the fruit fly Drosophila melanogaster, an omnivorous human commen-sal, and determined its sensitivity to an extended set of stimuli that humans find sweet. Flies were tested with all sweeteners in 2 assays that measured their taste reactivity (proboscis extension assay) and their ingestive preferences (free roaming ingestion choice test). A total of 21 sweeteners, comprised of 11 high-potency sweeteners, 2 amino acids, 5 sugars, 2 sugar alcohols, and a sweet salt (PbCl2), were tested in both assays.We found that wild-typeDrosophila responded appetitively tomost high-potency sweeteners preferred by humans, even those not considered sweet by rodents or new world monkeys. The similarities in taste preferences for sweeteners suggest that frugivorous/omnivorous apes and flies have evolved promiscuous carbohydrate taste detectors with similar affinities for myriad high-potency sweeteners. Whether these perceptual parallels are the result of con-vergent evolution of saccharide receptor–binding mechanisms remains to be determined. Key words: comparative taste, convergent evolution, detection, high-potency sweeteners, ingestion, tast