Like sweets? You're more like a fruit fly than you think...

“The similarity between human and fly responses to sweeteners is astounding, especially in light of the differences in their taste receptors,” notes Gordesky-Gold, a Drosophila (fruit fly) geneticist at Monell.

Sweet receptors belong to a large family of receptors known as G-protein coupled receptors (GPCRs), which are involved in biological processes throughout the body. Human and fly sweet taste GPCRs are presumed to have markedly different structures, an assumption that is based on differences in the genes that code for them.

Since substances will only taste sweet if they are able to bind to and activate a receptor, these two structurally different types of sweet receptors must have similar ‘binding regions’ that fit the same range of molecular shapes.

“That genes could be so divergent in sequence and so similar in physiology and function is truly striking,” says Breslin. “This is a wonderful example of convergent evolution in perceptual behavior, where evolution has taken two different routes to address pressures imposed by shared environment and nutrition.”

Future work will be directed towards modeling how these two structurally different sweet receptors could have highly overlapping sweetener affinities. Such knowledge will increase understanding of how molecules bind to GPCRs, which are targets for many pharmaceutical drugs.

The research was supported by the National Institute on Deafness and Other Communication Disorders.

The Monell Chemical Senses Center is a nonprofit basic research institute based in Philadelphia, Pennsylvania. For 40 years, Monell has been the nation’s leading academic research center focused on understanding the senses of smell and taste: how they function and affect lives from before birth through old age. Using a multidisciplinary approach, scientists collaborate in the areas of: sensation and perception, neuroscience and molecular biology, environmental and occupational health, nutrition and appetite, health and well being, and chemical ecology and communication. For more information about Monell, visit www.monell.org.