Bitter taste receptor genes of primates

Bitter taste perception plays a critical role in deterring animals from consuming harmful and toxic substances. To characterize the evolution of primate Tas2rs and test whether dietary preference has shaped the Tas2rs repertoire of primates, we identified Tas2r genes of 35 genomes including 16 Cercopithecidae species, 6 Hominidae species, 4 Cebidae species, 3 Lemuridae species, and other 6 species. The results showed that the total numbers of primates' Tas2rs ranged from 27 to 51, which concentrated on 2–4 scaffolds of each species and the closely related genes tandemly duplicated in the same scaffold. Phylogenetic construction revealed that the Tas2r genes can be divided into 21 clades, among which, anthropoid-specific clades, Prosimii-specific clade, clades with multiple gene copies, or even Cercopithecidea-specific Tas2rs were detected. In addition, phylogenetically independent contrast (PIC) analysis revealed that the number of intact Tas2rs was significantly correlated with feeding preferences. Altogether, our data supported diet as a driving force of primate Tas2rs evolution, and Cercopithecidae species have developed some specific Tas2rs during the evolutionary process. These results are probably because most Cercopithecidae species feed on plants containing many toxins, and it is necessary to develop specialized Tas2rs to protect them from poisoning.