Figure 1. Lgr5+ stem cells remain in their homeostatic location, but Lgr5 progeny repopulated the epidermal basal layer after UV overexposure in haired mice.

Paraffin sections of control mice and mice that received an UV overexposure were stained with an anti-EGFP antibody A-E; whole mounts F-J were stained for LacZ expression (representative pictures are shown). A+F show Lgr5+ stem cells and their progeny in control mice without any UV exposure (homeostasis). B-E show the location of Lgr5+ stem cells at different time points after UV overexposure; no differences were observed compared to the control mice (see arrows). G-J show the Lgr5 progeny at different time points after overexposure. One week after overexposure progeny clearly migrated out of the hair follicle into the epidermal basal layer (I), this was not observed in control mice. Hair follicle orifice (in H+I) contoured; and arrow in H points at rim staining. scale bar = 100μm (in A-G and J), scale bar = 50μm (H+I).