Fig. 4. Hair reconstitution assay showing multipotent capacity of UI keratinocytes. (A-H) FACS-sorted keratinocyte populations were mixed with dermal fibroblasts and injected into silicon graft chambers. Chambers were removed 1 week after cell injection and images of reconstituted skin and hair were captured 6 weeks post grafting. The number of FACS-sorted keratinocytes implanted in each graft is indicated. (B,D,F,H) Side view of each panel above. Dashed circle designates the graft perimeter (G,H). (I-U) H-2K^b (I,L,M,O,T), H-2K^q (J-K,N,P,T) and GFP (Q-S,U) immunofluorescent detection in C57Bl/6 (I,K) and nude (J,L) skin and a skin graft reconstituted from UI (M-S) or IFE + IFD (T-U) cells. Arrowheads indicate positive immunofluorescence and arrow points to boundary between grafted epidermis (H-2K^b-positive) and endogenous nude epidermis (H-2K^q-positive) at the graft periphery (T). DF, dermal-fibroblast-only graft (control); DP, dermal papilla; bl, basal layer; sl, suprabasal layer. Dashed line delineates epidermal basal layer (K,L,R) or encircles dermal papilla cells (M-N). Scale bars: 20 µm.