Fig. 3.

Genetic deletion of Shh in K5⁺ progenitor cells does not alter taste bud renewal. (A) Krt5^rtTA;tetO^Cre;Shh^flox/flox (K5-ShhcKO) mice were fed dox for 14, 21 or 42 days. (B) Deleting Shh in K5 progenitors results in Shh^neg taste precursors (marked with crosses). (C-E) Shh-expressing precursor cells are evident in most control taste bud profiles using Nomarksi optics (C) but absent in most mutant profiles (D,E). (F) Shh mRNA expression is reduced in K5-ShhcKO epithelium, although because of high variability in control values, this difference is not significant. Gli1 expression does not differ between mutants and controls. (G,H) The number of K8⁺ typical (G) and atypical (H) FFP does not differ between control and K5-ShhcKO mice after 14, 21 or 42 days. (I,J) K5-ShhcKO does not affect taste bud size (K8⁺ pixels) within typical (I) and atypical (J) FFP. Black dashed lines indicate basement membrane; black circles indicate taste buds; mc, mesenchymal core. Scale bars: 25 μm. n=3 or 4 mice per condition. Data are presented as mean±s.d. analyzed using Student's t-test (E) or two-way ANOVA (G-J). ***P<0.001.