Open questions in sweet, umami and bitter taste genetics

Sweet, umami and bitter tastes are in large part mediated by G-protein coupled receptors of taste type 1 (TAS1R) and taste type 2 (TAS2R) families. The genetics and molecular function of TAS receptors has been extensively explored, but more recently studies have identified these receptors in extra-oral locations. This has opened new perspectives on the function and evolutionary role of these receptors, and given rise to the possibility of using them as targets for personalized health interventions. In addition, these findings have generated new questions about the genetics of TAS1Rs and TAS2Rs that await answers. Here, we address the questions that we consider to be the most salient and intriguing and suggest more comprehensive theoretical and experimental approaches that could help to solve them.