Histopathology of mucin layer-producing tissues in mice. (a) Palpebral conjunctiva in the upper or lower eyelids. PAS+ goblet cells, indicated by arrowheads, are observed in the epithelium of the palpebral conjunctiva. The number of goblet cells decreased in BXSB with age, but not in BXSB-Yaa. PAS staining. Bars = 100 µm. CS: conjunctival sac. (b) Goblet cell density in the conjunctival epithelium. BXSB: BXSB/MpJ. BXSB-Yaa: BXSB/MpJ-Yaa Each bar represents the mean ± SE (n = 4). *Significant strain difference at the same age, Mann–Whitney U test. †Significant difference from the other groups, Kruskal–Wallis test followed by the Scheffe’s method. (A color version of this figure is available in the online journal.)