Analysis of taste bud number and distribution in lingual papillae from 5-8 week-old wild-type and p27 -nullizygous mice. (A, B) Flat-mounts of superficial epithelial layers from p27+/+ (A) and p27-/- (B) tongues. Locations of individual FG papillae are visible as round or oval openings in the tissue (arrowheads). These were counted to estimate FG papillae number. (C, D) Light micrographs of Toluidine Blue-stained JB-4 sections showing wild-type (C) and nullizygous (D) CV papillae. The lingual epithelium and the distribution of taste buds are similar in both genotypes. Arrows in (C) point to individual taste pores, which were counted in serial sections to estimate the number of CV taste buds. (E) Total numbers of FG and CV taste buds based on counts of papillae and taste pores, respectively. Graph of means ± SEM for 4 replicates. (Student's t-test; t = 0.98 (FG) and 0.97 (CV), df = 6; p > 0.10) Scale bar (A and B): 100 μm. Scale bar (C and D): 50 μm.