Biochemical and immunohistochemical localization of alpha and beta keratin in avian scutate scales

Abstract

Abstract We have determined the distribution of alpha and beta keratins in avian scutate scales using SDS‐PAGE and indirect immunofluorescence with non‐cross‐reacting rabbit antisera prepared to both alpha and beta keratins. Contrary to previous studies, we find that alpha keratin is definitely present in the epidermis of the outer scale surface as well as that of the inner surface and hinge region of the scale. In fact, all six alpha keratin polypeptides found in the whole scale epidermis are also present in epidermis taken exclusively from the outer scale surface. Three of these polypeptides demonstrate a specific enrichment in the epidermis of the outer scale surface when compared to the polypeptides of the entire scale epidermis. Immunofluorescence studies specifically localize the alpha keratins of the outer scale epidermis in the Stratum Basale and Stratum Intermedium, but the beta keratins are restricted to the Stratum Intermedium and Stratum Intermedium and Stratum Corneum.