| Functional |
"Mammalian sweet taste is primarily mediated by the type 1 taste receptor Tas1r2/Tas1r3, whereas Tas1r1/Tas1r3 act as the principal umami taste receptor." |
10.1073/pnas.1118360109 |
| Mutation Description |
"In exon 1 of Tas1r2, both the sea lion and fur seal (Otariidae family) have an ATA instead of ATG in the start codon position. This mutation is predicted to prevent Tas1r2 from being translated (Fig. 1 A and B and SI Appendix, Fig. S1A). Additionally, we detected a 1-bp deletion between 579 and 580 bp in exon 3 of the sea lion Tas1r2 (...). These defects in the coding sequence predict that the sea lion and fur seal Tas1r2 genes are pseudogenes." |
10.1073/pnas.1118360109 |
| Timing of Loss |
"The widespread loss of Tas1r2 in species of the order Carnivora, the variance in their lineages, and the independent pseudogenizing mutations among species in distinct families strongly support the hypothesis that the loss of Tas1r2 occurred independently many times during the evolution of the order Carnivora." |
10.1073/pnas.1118360109 |
| Phenotypic |
"It seems most likely that changes in dietary behavior in the process of becoming obligate carnivores may favor the loss of a functional Tas1r2, arguing for convergent evolution of pseudogenized Tas1r2." |
10.1073/pnas.1118360109 |