title: Bitter, sweet and umami taste receptors and downstream signaling effectors: Expression in embryonic and growing chicken gastrointestinal tract.
abstract: 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. The chicken genome contains three bitter taste receptors termed ggTas2r1, ggTas2r2, and ggTas2r7, and the sweet/umami receptors ggTas1r1 and ggTas1r3, but it lacks the sweet receptor ggTas1r2. The aim of this study was to identify and determine the expression of genes related to taste perception in the chicken GIT, both at the embryonic stage and in growing chickens. The results of this study demonstrate for the first time, using real-time PCR, expression of the chicken taste receptor genes ggTas2r1, ggTas2r2, ggTas2r7, ggTas1r1, and ggTas1r3 and of their downstream protein-encoding genes TRPM5, α-gustducin, and PLCβ2 in both gustatory tissues-the palate and tongue, and extra-gustatory tissues-the proventriculus, duodenum, jejunum, ileum, cecum, and colon of embryonic day 19 (E19) and growing (21 d old) chickens. Expression of these genes suggests the involvement of taste pathways for sensing carbohydrates, amino acids and bitter compounds in the chicken GIT.
authors.affiliation: Department of Animal Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel.
authors.forename: Shira L
authors.initials: SL
authors.lastname: Cheled-Shoval
authors.affiliation: Institute of Animal Science, ARO, the Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel.
authors.forename: Shelly
authors.initials: S
authors.lastname: Druyan
authors.affiliation: Department of Animal Science, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University, Rehovot 76100, Israel zehava.uni@mail.huji.ac.il.
authors.forename: Zehava
authors.initials: Z
authors.lastname: Uni
mesh_terms: D000818:Animals; D002642:Chick Embryo / Q000378:metabolism*; D002645:Chickens / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction
chemical_list: D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled
keywords: chicken; gastrointestinal tract; gene expression; taste receptor