Fig. 7. Structural analysis of the epithelial tongue. Light microscopical (A-D) and ultrastructural (E-H) views of the epidermal tongue at the margin of 5-day wounds as it cuts a path between the granulation tissue and the overlying eschar. The migrating keratinocytes of the hyperproliferative epithelium in control mice are relatively loosely associated with each other, showing extensive intercellular spacing (compare asterisk in E with that in F). By contrast, wound margin keratinocytes of K5ß1-null mice are densely packed (compare A,C,E with B,D,F). The boxes represent the approximate areas shown in the higher magnification figures. The number of tonofilaments attached to the desmosomes was significantly reduced in K5ß1-null mice (H) compared with controls (G) (indicated by arrows). Es, eschar; G, granulation tissue; HE, hyperproliferative epithelium; N, nucleus. Scale bars: 50 µm in A,B; 20 µm in C,D; 1 µm in E-H.