Figure 1

Endogenous expression pattern of Nrg3 , K14- Nrg3 transgene, and postnatal phenotype of a K14- Nrg3 founder mouse. (A) Nrg3 is expressed in the developing hair follicles at E14.5. Inset shows frozen section of the whole mount which confirmed the localization of Nrg3 in the nascent hair follicles (brackets). Arrowheads indicate intense basal epithelial expression. Suprabasal and diffuse mesenchymal Nrg3 expression are also observed. The scale bar represents 100 μm. (B) Nrg3 is expressed in the granular and cornified layers and in a few basal cells (arrows) of the postnatal epidermis and at low to moderate levels in the hair follicles in the outer root sheath and inner root sheath at P7. The scale bar represents 50 μm in (B). (C) Transgene used for ectopic expression of Nrg3. The transgene includes a human K14 promoter, a rabbit β-globin intron and an SV40 polyadenylation site. (D) Phenotype of one K14-Nrg3 founder at P7. Mutant mice are hairless and have thick, pale and wrinkled skin. A non-transgenic littermate is on the left. b, bulge; irs, inner root sheath; ors, outer root sheath; sg, sebaceous gland.