Abstract
Bitter taste plays an important role in avoiding toxin ingestion and inducing innate avoidance behaviors. Difference in bitter taste sensitivity might reflect species-specific diets during mammalian evolution. In addition to diet, it was recently reported that the receptors are involved in the immuno-system against bacteria and parasites. TAS2R38 has been studied for bitter taste sensitivity, especially for bitter compound Phenylthiocarbamide (PTC). Here, we report characterization of TAS2R38 in four species of Sulawesi macaque, M. hecki (N: 13), M. tonkeana (N: 12), M. nigrescens (N: 5) and M. nigra (N: 14). We conducted behavioral experiment on PTC acceptance and later functional analysis on amino acid residue(s) of TAS2R38 responsible for low bitter taste sensitivity. Our result shows that both M. tonkeana and M. nigra were found with “non-taster” but exhibited different pattern in genetic aspect. Amino acid changes at position 117, 130, 134 of M. tonkeana, whereas one base insertion caused early stop codon at site 178 of M. nigra, leading to non-taster phenotype separately. This finding might give a clue for clarifying evolutionary relationship and dietary habits among the four species. In addition, it will help to elucidate the ecological, evolutionary, and neurobiological aspects of bitter taste perception of primates, as bitter taste may be related to the plants they consume.
