Faithful expression of GFP from the PLCbeta2 promoter in a functional class of taste receptor cells.
Phospholipase C-type beta2 (PLCbeta2) is expressed in a subset of cells within mammalian taste buds. This enzyme is involved in the transduction of sweet, bitter, and umami stimuli and thus is believed to be a marker for gustatory sensory receptor cells. We have developed transgenic mice expressing green fluorescent protein (GFP) under the control of the PLCbeta2 promoter to enable one to identify these cells and record their physiological activity in living preparations. Expression of GFP (especially in lines with more than one copy integrated) is strong enough to be detected in intact tissue preparations using epifluorescence microscopy. By immunohistochemistry, we confirmed that the overwhelming majority of cells expressing GFP are those that endogenously express PLCbeta2. Expression of the GFP transgene in circumvallate papillae occurs at about the same time during development as endogenous PLCbeta2 expression. When loaded with a calcium-sensitive dye in situ, GFP-positive taste cells produce typical Ca2+ responses to a taste stimulus, the bitter compound cycloheximide. These PLCbeta2 promoter-GFP transgenic lines promise to be useful for studying taste transduction, sensory signal processing, and taste bud development.
Kim
Joung Woul
JW
Department of Physiology and Biophysics, University of Miami Miller School of Medicine (RMSB 4040), 1600 NW 10th Avenue, Miami, FL 33136, USA.
Roberts
Craig
C
Maruyama
Yutaka
Y
Berg
Stephanie
S
Roper
Stephen
S
Chaudhari
Nirupa
N
D000818:Animals; D002118:Calcium / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D005456:Fluorescent Dyes; D015870:Gene Expression; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000096:biosynthesis* / Q000235:genetics; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D008822:Mice, Transgenic; D054799:Phospholipase C beta; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis* / Q000235:genetics; D013268:Stimulation, Chemical; D013650:Taste Buds / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D010738:Type C Phospholipases / Q000096:biosynthesis / Q000235:genetics*
D005456:Fluorescent Dyes; D007527:Isoenzymes; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; D003513:Cycloheximide; D010738:Type C Phospholipases; D054799:Phospholipase C beta; C518037:Plcb2 protein, mouse; D002118:Calcium