Wnt-beta-catenin signaling initiates taste papilla development.
Fungiform taste papillae form a regular array on the dorsal tongue. Taste buds arise from papilla epithelium and, unusually for epithelial derivatives, synapse with neurons, release neurotransmitters and generate receptor and action potentials. Despite the importance of taste as one of our five senses, genetic analyses of taste papilla and bud development are lacking. We demonstrate that Wnt-beta-catenin signaling is activated in developing fungiform placodes and taste bud cells. A dominant stabilizing mutation of epithelial beta-catenin causes massive overproduction of enlarged fungiform papillae and taste buds. Likewise, genetic deletion of epithelial beta-catenin or inhibition of Wnt-beta-catenin signaling by ectopic dickkopf1 (Dkk1) blocks initiation of fungiform papilla morphogenesis. Ectopic papillae are innervated in the stabilizing beta-catenin mutant, whereas ectopic Dkk1 causes absence of lingual epithelial innervation. Thus, Wnt-beta-catenin signaling is critical for fungiform papilla and taste bud development. Altered regulation of this pathway may underlie evolutionary changes in taste papilla patterning.
Liu
Fei
F
Department of Dermatology and Cell, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA.
Thirumangalathu
Shoba
S
Gallant
Natalie M
NM
Yang
Steven H
SH
Stoick-Cooper
Cristi L
CL
Reddy
Seshamma T
ST
Andl
Thomas
T
Taketo
Makoto M
MM
Dlugosz
Andrzej A
AA
Moon
Randall T
RT
Barlow
Linda A
LA
Millar
Sarah E
SE
D000818:Animals; D000831:Animals, Newborn; D002478:Cells, Cultured; D005260:Female; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D009024:Morphogenesis / Q000235:genetics; D011247:Pregnancy; D015398:Signal Transduction / Q000235:genetics; D013650:Taste Buds / Q000196:embryology* / Q000254:growth & development; D051153:Wnt Proteins / Q000502:physiology*; D051176:beta Catenin / Q000235:genetics / Q000502:physiology*
C501127:Dkk1 protein, mouse; D036341:Intercellular Signaling Peptides and Proteins; D051153:Wnt Proteins; D051176:beta Catenin