抄録
Animals have evolved various sensory systems to identify appropriate foods and avoid harmful substances. Taste, a chemical sense, plays a central role in food selection. This review explores the functional evolution of taste receptors in primates in the context of dietary diversification. Special focus is placed on bitter taste receptors (TAS2Rs), which detect potentially harmful compounds. Primates exhibit a wide range of dietary preferences—from insectivory and frugivory to folivory and bamboo specialization—making them suitable models for studying the link between taste perception and feeding ecology. The evolution of bitter taste receptors in association with diet has been studied from two major aspects: the number of receptor genes in the genome and the function of individual receptors. Comparative genomic analyses have revealed that TAS2R gene repertoire size correlates with dietary strategies, with omnivorous species typically retaining more TAS2Rs than specialists (e.g., folivorous species). In-depth functional analyses of individual bitter taste receptors, such as TAS2R16, have uncovered conservation and diversification of receptive ranges to plant-derived compounds in a variety of primate lineages. These studies have also identified potentially adaptive changes in receptor sensitivity in specialists, such as folivorous or bamboo-eating primates. Furthermore, studies of other taste receptors, including TAS2R38 and the sweet/umami taste receptor TAS1Rs, suggest evolutionary changes in their receptor functions associated with dietary transitions to folivory. As high-quality primate genomes become more accessible, integrated studies combining behavior, genomics, and receptor function will be key to elucidating how primates diversified their dietary strategies through sensory adaptation. This integrated approach not only enhances our understanding of primate evolution but also sheds light on the evolutionary origins of human taste perception.
