Taste receptors and their ecological niches: cats, dogs, and other vertebrates.

This article examines the evolution and functional diversity of taste receptors, particularly TAS1Rs and TAS2Rs, across various vertebrate species, emphasizing how feeding ecology shapes taste receptor repertoires. It highlights species-specific adaptations such as the loss of the sweet taste receptor TAS1R2 in obligate carnivores like domestic cats and certain marine mammals, the repurposing of the umami receptor TAS1R1/TAS1R3 for sweet detection in hummingbirds, and the variation in bitter taste receptor gene numbers linked to dietary toxins. The review also discusses differences in umami receptor ligand specificity among species, including primates and carnivores, and notes that taste receptor evolution reflects ecological niches and dietary specialization. Finally, it underscores the need for further comparative studies to explore novel taste modalities and the broader biological roles of taste receptors beyond the oral cavity.