Ecad is accessible from the luminal side of intestinal villi and is mainly detectable around GCs. (A) Intestinal tissue of iFABP-hEcad transgenic mice was fixed and stained for luminally accessible (acc) hEcad before tissue permeabilization, total hEcad, and nuclei after tissue permeabilization. The image is an optical section of an intestinal villus. Right panels show separated channels and merge of boxed regions, showing accessible hEcad on the apical and lateral sides of cells. (B) Intestinal cells express luminally accessible hEcad. Stack projection of nonpermeabilized intestinal villi stained with WGA and for accessible hEcad and nuclei. The arrow shows a site of luminally accessible hEcad at the villus tip. Right panels show magnification of the boxed region, which shows a GC surrounded by a ring of accessible hEcad at its apical pole. Pictures are representative of three mice. Bars, 10 µm. (C) Schematic representation of an intestinal villus. (D) Quantification of cell subtypes in intestinal villi. GCs, 2.8%; non-GCs, 97.2%. n = 20 villi from two mice. (E) Quantification of cell subtypes expressing luminally accessible hEcad in intestinal villi. n = 20 villi from two mice. (F) Relative proportion of cell types with accessible hEcad. n = 20 villi from two mice. (D–F) Error bars indicate SD.