Quantification of microvillous cell density in the most superficial layer of the MOE. (A) Image of an MOE dorsal recess from a ChAT-eGFP mouse, showing ChAT/Trpm5-expressing microvillous cells (GFP+) in the most superficial layer, a region above the supporting cell nuclei. (B) A higher-magnification view of the DAPI-stained nuclei in the dorsal MOE. Arrowheads point to nuclei of GFP+ microvillous cells. (B’) Overlay of GFP signal onto B. (C) Image of an MOE dorsal recess from an Skn-1a-/- mouse. Arrows in B and C point to nuclei that do not belong to GFP+ microvillous cells. (D) Plot of the averaged density per surface area of DAPI-stained nuclei and GFP+ cells in the most superficial layer of the MOE from ChAT-eGFP mice. Counting was conducted from the dorsal recess and septum of the MOE. Approximately 80% of the cells in the area are GFP+ microvillous cells. (E) Comparison of averaged nucleus density, showing approximately 73% reduction in the nucleus density of Skn-1a-/- mice compared with that of ChAT-eGFP mice. Scale bars: 100 μm in A, 20 μm in B-D.