Fig. 3. In vivo screening for SPRR4 expression. (A) RT-PCR analysis of SPRR4 expression. Epidermal RNA (lanes 1-7) and RNA isolated from primary cultured keratinocytes (lanes 8-11) were analyzed with SPRR4, involucrin and GAPDH-specific primers. (B) In situ hybridization performed on different skin samples. Sense (a,c,e) and antisense (b,d,f) probes from either SPRR4 (a-d) and SPRR2 (e,f) were analyzed. Melanin caps (c, filled arrows) and SPRR2-positive staining (f, open arrows) are indicated. Bar, 30 µm.