Keratin polypeptides in the epidermis of the larval (ammocoete) sea lamprey, Petromyzon marinus L., show a cell type-specific immunolocalization

Abstract

Using immunofluorescent staining, the localization of keratin polypeptides in the epidermis of the larval (ammocoete) sea lamprey, Petromyzon marinus L., is described. Immunostaining with monoclonal antibodies against human keratin polypeptides showed that immunoreactivity was distributed in a cell type-specific pattern among the epidermal cells of ammocoete skin: immunoreactivity for keratin polypeptides Nos. 7 and 18 was prominent in skein and granular cells, respectively, while that for keratin polypeptide No. 19 was in cytoplasmic regions near the plasma membrane of both specialized (skein, granular, and mucous) and germinal cells. Positive immunostaining with a polyclonal antibody against bovine keratins suggests that there are other, as yet unidentified, keratin polypeptides in the epidermis. The significance of keratins as molecular markers of epidermal development is discussed.