Figure 4.

Mouse sweat-gland maintenance and wound repair. (A) In adult skin, SG are quiescent, whereas the myoepithelial and luminal cells that form the sweat duct are continually turned over, being replaced by lineage committed progenitor cells (inset). (B) Transgenic deletion of glandular cells using diphtheria toxin (DT) receptor mobilizes glandular progenitors to replenish the lost cells. (C) Wounding of the epidermis adjacent to the sweat gland triggers proliferation of the duct progenitor cells, but not the sweat gland, to repair the connection of the duct to the epidermal surface. Green shading indicates nondividing cells as determined H2BGFP proliferation assay (see Fig. 1).