Proliferating cells in CV papillae from 5-6 week-old wild-type and p27 -nullizygous mice. Confocal images illustrating anti-PCNA and TROMA-I double-labeling in wild-type (A) and mutant (B) mice. Taste cells are visualized by magenta TROMA-I staining. Anti-PCNA-labeled cycling cells (green) are found only basal or lateral to taste buds in both genotypes. Maximum projection images representing z-series of 10 optical sections separated by 1 μm steps. Scale bar: 50 μm.