Fig. 4. Expression of hair bulb markers in Hr^-/- skin. (A) Normal expression of hair bulb markers during initial hair growth. In situ hybridization of sagittal sections from backskin with cRNA probes specific for Lef1 (top panels, P6) and sonic hedgehog (Shh) (bottom panels, P9) in wild-type (+/+), Hr^-/- (-/-). mice (B) Absence of hair markers during second anagen. In situ hybridization of sagittal sections from backskin of P28 mice with cRNA probes specific for Lef1 and Shh in wild-type (+/+), Hr^-/- (-/-). Arrowheads, gene-specific signal; arrows, pigmented cells; m, matrix; dp, dermal papilla; epi, epidermis; u, utricle. Scale bar: 50 µm.