title: Genetic labeling of Tas1r1 and Tas2r131 taste receptor cells in mice.
abstract: Characterization of the peripheral taste system relies on the identification and visualization of the different taste bud cell types. So far, genetic strategies to label taste receptor cells are limited to sweet, sour, and salty detecting cells. To visualize Tas1r1 umami and Tas2r131 bitter sensing cells, we generated animals in which the Tas1r1 and Tas2r131 open reading frames are replaced by expression cassettes containing the fluorescent proteins mCherry or hrGFP, respectively. These animals enabled us to visualize and quantify the entire oral Tas1r1 and Tas2r131 cell populations. Tas1r1-mCherry cells were predominantly detected in fungiform papillae, whereas Tas2r131-hrGFP cells, which are ~4-fold more abundant, were mainly present in foliate and vallate papillae. In the palate, both cell types were similarly distributed. Mice carrying both recombinant alleles demonstrated completely segregated Tas1r1 and Tas2r131 cell populations. Only ~50% of the entire bitter cell population expressed hrGFP, indicating that bitter taste receptor cells express a subset of the bitter receptor repertoire. In extragustatory tissues, mCherry fluorescence was observed in testis and hrGFP fluorescence in testis, thymus, vomeronasal organ, and respiratory epithelium, suggesting that only few extraoral sites express Tas2r131 and Tas1r1 receptors at levels comparable to taste tissue.
authors.affiliation: Department of Molecular Genetics, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Arthur-Scheunert-Allee 114-116, 14558 Nuthetal, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Voigt
authors.forename: Sandra
authors.initials: S
authors.lastname: Hübner
authors.forename: Kristina
authors.initials: K
authors.lastname: Lossow
authors.forename: Irm
authors.initials: I
authors.lastname: Hermans-Borgmeyer
authors.forename: Ulrich
authors.initials: U
authors.lastname: Boehm
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Meyerhof
mesh_terms: D000483:Alleles; D000818:Animals; D055879:Gene Knock-In Techniques; D005822:Genetic Vectors / Q000235:genetics / Q000378:metabolism; D017404:In Situ Hybridization, Fluorescence; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D016366:Open Reading Frames; D010159:Palate / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics* / Q000378:metabolism; D013650:Taste Buds / Q000378:metabolism; D000097573:Red Fluorescent Protein
chemical_list: D008164:Luminescent Proteins; D043562:Receptors, G-Protein-Coupled; D000097573:Red Fluorescent Protein; C578844:Tas2r131 protein, mouse; C431926:taste receptors, type 1