Ligand binding modes from low resolution GPCR models and mutagenesis: chicken bitter taste receptor as a test-case.

Bitter taste is one of the basic taste modalities, warning against consuming potential poisons. Bitter compounds activate members of the bitter taste receptor (Tas2r) subfamily of G protein-coupled receptors (GPCRs). The number of functional Tas2rs is species-dependent.

From Cell to Beak: In-Vitro and In-Vivo Characterization of Chicken Bitter Taste Thresholds.

Bitter taste elicits an aversive reaction, and is believed to protect against consuming poisons. Bitter molecules are detected by the Tas2r family of G-protein-coupled receptors, with a species-dependent number of subtypes. Chickens demonstrate bitter taste sensitivity despite having only three bitter taste receptors-ggTas2r1, ggTas2r2 and ggTas2r7.

Detecting thresholds for bitter, umami, and sweet tastants in broiler chicken using a 2-choice test method.

The sense of taste has a key role in nutrient sensing and food intake in animals. A standardized and simple method for determination of tastant-detection thresholds is required for chemosensory research in poultry. We established a 24-h, 2-alternative, forced-choice solution-consumption method and applied it to measure detection thresholds for 3 G-protein-coupled receptor-mediated taste modalities-bitter, sweet, and umami-in chicken.

Bitter, sweet and umami taste receptors and downstream signaling effectors: Expression in embryonic and growing chicken gastrointestinal tract.

Taste perception is a crucial biological mechanism affecting food and water choices and consumption in the animal kingdom. Bitter taste perception is mediated by a G-protein-coupled receptor (GPCR) family-the taste 2 receptors (T2R)-and their downstream proteins, whereas sweet and umami tastes are mediated by the GPCR family -taste 1 receptors (T1R) and their downstream proteins. Taste receptors and their downstream proteins have been identified in extra-gustatory tissues in mammals, such as the lungs and gastrointestinal tract (GIT), and their GIT activation has been linked with different metabolic and endocrinic pathways in the GIT.

Perinatal administration of a bitter tastant influences gene expression in chicken palate and duodenum.

Bitter taste receptors (Tas2rs) and downstream effectors are responsible for mediating bitterness perception and regulation of food choice in mammals. Using RT-PCR, we demonstrated the expression of three Tas2rs and taste signal transduction molecules, α-gustducin, PLCβ2, and TRPM5, in the palate, tongue, and gastrointestinal tract sections in chicken. The bitter tastant quinine activates all three chicken Tas2rs in vitro as shown using calcium-imaging assays of transfected cells.