Figure 4.

Polarization of collectively migrating basal cells allow shield extension. (A) Histological sections of organotypic wound cultures were separated into six different regions dependent on the distance to the wound, and the nuclear major axis of basal keratinocytes was analyzed. The inset shows the magnification of the wound margin (box) in region 3 (R3) to illustrate the change of nuclear major axis orientations (red lines). (B) Plotted nuclear orientation degrees of the major axis analysis for the respective regions 12 and 36 h after wounding. (C) E-cadherin staining of representative histological sections of unwounded tissue and wound margin. Compared with unwounded tissue cells within the wound margin show a nuclei movement according to the cell boundaries rearward in opposed direction of cell migration. The arrows indicate displacement vectors. Asterisks indicate the geometrical center of the cell. (D) Nuclei deformation of wound cultures indicated by white arrows are shown by representative DAPI stains. The arrowhead indicates the wound margin. Broken lines denote dermal–epidermal junction. The data shown are from a single representative experiment. For the experiment shown, n = 5; 2,341 cell nuclei were analyzed in total; **, P ≤ 0.01, Student’s t test. Bars, 100 µm.