Adhesion-dependent nuclear movement occurs in WT epidermal MKCs and is exaggerated in Sun2^−/− MKCs. (A) SUN2 and E-cadherin (E-cad) localization in WT MKCs in low calcium (Ca²⁺) or in high Ca²⁺ medium for 24 h. (B) Diagram of a MKC colony illustrating interior adhesions (magenta) at cell–cell contacts opposite from the free edge in cells at the colony periphery. Nuclear position (asterisks) is biased toward interior adhesions and away from the cell centroid (marked with x’s). (C and D) E-cad and nuclear position in WT MKCs cultured in high Ca²⁺ medium for 0 and 24 h. Each cell periphery is outlined (dotted lines), and the nuclear centroid (asterisks) and cell centroid (x’s) are shown in matching colors. Arrow in D indicates a cell without a free edge with a central nuclear position. (E) Plots of the nuclear centroid to cell centroid distance normalized to cell radius during MKC adhesion formation at indicated time points after Ca²⁺ addition. n > 50 cells per time point (representative of three experiments). Error bars indicate SDs. Asterisks denote indicated significance (*, P ≤ 0.05; ***, P ≤ 0.001; ****, P ≤ 0.0001; ANOVA with Tukey’s posttest). (F and G) E-cad and nuclear position in WT and Sun2^−/− MKCs cultured in high Ca²⁺ medium for 24 h. Nuclei (asterisks) directly abut E-cad–positive AJs (dotted lines) in Sun2^−/− MKCs at colony edges (G, inset). (H) Quantification of nuclear position as in E for WT and Sun2^−/− MKCs. n > 50 cells per genotype at each time point (representative of three experiments). Error bars indicate SDs. Statistical significance determined by unpaired, two-tailed t test. AU, arbitrary unit.