(PHILADELPHIA) -- Of the five senses, taste is one of the least understood, but now researchers at the University of Pennsylvania School of Medicine have come one step closer to understanding how the sense of taste develops. They have pinpointed a molecular pathway that regulates the development of taste buds. Using genetically engineered mice, they discovered that a signaling pathway activated by small proteins called Wnts is required for initiating taste-bud formation. They have also determined that Wnt proteins are required for hooking up the wiring of taste signals to the brain.
Senior author Sarah E. Millar, PhD, Associate Professor in the Departments of Dermatology and Cell and Developmental Biology, Penn postdoctoral fellow Fei Liu, PhD, and colleagues report their findings in the most recent online issue of Nature Genetics. "The developmental biology of taste is underexplored," says Millar of her team's impetus for the study.
The researchers demonstrated that blocking the action of Wnt proteins in surface cells of the developing tongue prevents taste-bud formation, while stimulating Wnt activity causes the formation of excessive numbers of enlarged taste papillae that are able to attract taste-related nerve fibers. This study represents the first genetic analysis of taste-organ initiation in mammals. While these studies were performed in mice, the researchers believe that their findings will also hold true for understanding the basis of taste-bud development in humans.
Taste buds are the sensory organs that transmit chemical stimuli from food and other sources to nerve cells, which convey these signals to the taste centers in the brain. Taste buds sit in the small bumps in the surface and sides of the tongue called papillae.
The signaling pathway activated by Wnt proteins is critical to the development of many organ systems, and its inappropriate activation causes human diseases including colon cancer. In previou
Contact: Karen Kreeger
University of Pennsylvania School of Medicine