Major taste loss in carnivorous mammals

• DOI: 10.1073/pnas.1118360109
• Publication Date: 2012-03-13T05:00:12Z
• Authors: Peihua Jiang; Jesusa Josue; Xia Li; Dieter Glaser; Weihua Li; Joseph G. Brand; Robert F. Margolskee; Danielle R. Reed; Gary K. Beauchamp
• Keywords: Taste receptor; Umami; Wine tasting

Mammalian sweet taste is primarily mediated by the type 1 receptor Tas1r2/Tas1r3, whereas Tas1r1/Tas1r3 act as principal umami receptor. Bitter a different group of G protein-coupled receptors, Tas2rs, numbering 3 to ∼66, depending on species. We showed previously that behavioral indifference cats toward sweet-tasting compounds can be explained pseudogenization Tas1r2 gene, which encodes To examine generality this finding, we sequenced entire coding region from 12 species in order Carnivora. Seven these nonfeline species, all are exclusive meat eaters, also have independently pseudogenized caused ORF-disrupting mutations. Fittingly, purifying selection pressure markedly relaxed with . In tests, Asian otter (defective ) no preference for compounds, but spectacled bear (intact did. addition inactivation , found sea lion Tas1r1 and Tas1r3 pseudogenized, consistent their unique feeding behavior, entails swallowing food whole without chewing. The extensive loss Tas1r function not restricted lion: bottlenose dolphin, evolved displays similar has three s inactivated, may lack functional bitter receptors. These data provide strong support view mammals widespread directly related specializations.