Fruit flies also have a family of taste-receptor genes, Yale University researchers report in the March 10 Science . Cells that make any of the newly found mammalian receptor proteins also produce all the others and gustducin. However, not all gustducin-producing cells make bitter receptors. Those cells may be involved in detecting sweetness, suggests taste researcher Nirupa Chaudhari of the University of Miami. When mixed with a bitter chemical in a test tube, the receptor proteins link to gustducin to trigger the next step in taste signaling, the NIH-UCSD team finds.
Taste is something that's more than just a test-tube reaction.
So, in the end, you have to relate everything back to an animal model. Mice that perceive the chemical all have one form of a bitter receptor called T2R5, while non-tasting mice had another. The new research gives a much more complete picture of how taste cells identify flavors, says Sue C. Kinnamon, a neuroscientist at Colorado State University in Fort Collins. The characterizations of the family of bitter receptors and the umami receptor have paved the way for scientists to finally understand how taste works, says Steven D. Roper of the University of Miami, a codiscoverer of the umami receptor. From Science News , Vol.