Figure 6

Immunohistochemistry using epidermal differentiation markers. Immunohistochemistry of sections of dorsal skin from transgenic mice and non-transgenic littermates at P7 with antibodies to the proteins indicated. (A and B) Expression of Filaggrin, a terminal differentiation marker, is maintained in the granular and cornified layers of non-transgenic (A) and K14-Nrg3 transgenic (B) skin. (C and D) K1, a marker for committed early differentiating cells, is expressed in the suprabasal layer of non-transgenic (C) and K14-Nrg3 transgenic (D) skin. (E and F) K14, a marker for basal proliferating keratinocytes, is expressed in the basal layer of non-transgenic skin and the ORS of the hair follicles (E) and is expressed at high levels throughout the basal, suprabasal, granular and cornified layers of K14-Nrg3 transgenic skin and ORS of the hair follicles (F). (G and H) Expression of K15 is normally restricted to basal keratinocytes as observed in non-transgenic littermates (G) and marks undifferentiated cells with low turn over. Expression of K15 is reduced in the basal IFE in K14-Nrg3 basal epidermis (H). K15 is expressed in the ORS, where it marks the bulge region of the hair follicle, in both normal and mutant epidermis (G and H). Basal expression of K15 in the IFE and ORS is denoted by arrows. The scale bar represents 50 μm.