<p><b>A,C,E,G. Chorda/Lingual</b>: K8 immunostaining to label taste bud cells and neurofilament (NF) to label fibers of the chorda tympani/lingual nerve innervation to FP and TB. <b>A</b>. In Control the Chorda/lingual innervation is throughout the FP core and forms a dense ‘basket’ under the TB at the apex of the papilla core. With HH/GLI suppression at specified time points in <i>K5GliR</i> (<b>C</b>), <i>epiGliR</i> (<b>E</b>), and <i>Gli2cKO</i> (<b>G</b>) mice, NF-positive fibers are retained in the FP even though papillae are of atypical morphology and TBs are lost (E) or much reduced (G). At the illustrated time points in all models there are substantial morphological effects, as seen in Figs <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006442#pgen.1006442.g001" target="_blank">1</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1006442#pgen.1006442.g002" target="_blank">2</a>. <b>B,D,F,H</b>. <b>Chorda tympani</b>: K8 immunostaining to label taste bud cells and P2X3 to label fibers of the chorda tympani nerve innervation to FP and TB. <b>B</b>. In Control for Chorda tympani innervation the P2X3-positive label is within fibers in the papilla core (arrow) and within the TB. With HH/GLI suppression at specified time points in <i>K5GliR</i> (<b>D</b>), <i>epiGliR</i> (<b>F</b>), and <i>Gli2cKO</i> (<b>H</b>) mice, P2X3-positive fibers (arrows) are retained in the FP and TB cells even though papillae are of atypical morphology and TBs are lost (F) or much reduced (H). Scale bar in H applies to all panels. * in H indicate areas of nonspecific staining in the surface epithelial cells.</p
