| 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 |
"Exon 4 appears to have been lost entirely based on using dog, cow, mouse, or human sequences, because queries and in exons 3 and 6 ORF-disrupting mutations were found (Fig. 4B). Specifically, there is a 20-bp ORFdisrupting insertion between 488 and 507 bp in exon 3 (Fig. 4B and SI Appendix, Fig. S9B), and there is a 1-bpORF-disrupting deletion in exon 6 between 378 and 379 bp (Fig. 4B). Thus, dolphin Tas1r2 also is a pseudogene." |
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 |