Intercellular adhesions are structurally and functionally perturbed in Sun2^−/− hair follicles. Transmission electron micrographs of P4 WT and Sun2^−/− follicles. (A and B) Overview of sectioned follicle structure, with the ORS at the edges of the image, followed by the companion (Cp), Henle (He), and Huxley (Hu) layers. Note the gaps between Sun2^−/− He cells (B, arrows). (C and D) WT He–He cell junctions were evenly spaced with classical electron-dense desmosome morphology (C and C′, arrow), whereas Sun2^−/− junctions included large gaps between cells, abnormal desmosome structure, and fewer desmosomes (D and D′, arrow). (E) Quantification of intermembrane spacings between He cells, displayed on a log₂ scale. n > 138 adhesions from two mice. (F) Quantification of linear desmosome density between He layer cells. n > 13 cells from two mice. (G) Quantification of desmosome length between He layer cells. n > 62 desmosomes from two mice. (H and I) A greater number of desmosomes (insets H′ and I′, arrows) were found between He and Hu layer cells in Sun2^−/− follicles. (J) Quantification of linear desmosome density between He and Hu cells. n > 19 cells from two mice. (K and L) Back skin from P4 WT and Sun2^−/− mice immunostained for Dsg4. Junctions between He and Hu layers were desmosome rich (boxes). (M) Mean fluorescence intensity per micrometer for stretches of He–Hu junctions. n > 13 junctions. In all cases, statistical significance was determined by unpaired, two-tailed t test. For box and whiskers plots, the bottom and top of the box display the 25th and 75th percentiles, whereas the central band represents the median. The whiskers indicate the minimum and maximum values, and the plus signs indicate the means.