Plasma membrane glycoproteins during anuran amphibian epidermal development

Summary A cytochemical and biochemical study of galactose (Gal) and N-acetyl-glucosamine (GlcNAc) containing glycoproteins of the anuran amphibian epidermis during development has been carried out. In premetamorphic tadpoles, theGriffonia simplicifolia II lectin (GS II, specific for N-acetyl glucosamine) bound to a glycoprotein of 49 kDa in the plasma membrane of all the epidermal strata showing a basal-to-apical binding gradient. During metamorphic climax GS II labeling was progressively polarized to the outermost plasma membrane. In epidermis from juveniles and adults the staining was observed mainly in a 52 kDa band.Griffonia simplicifolia I lectin (GS I, specific for galactose) also bound to a glycoprotein of about 49 kDa in tadpoles and 52 kDa in frogs. Furthermore, a GS I labeling in bands of about 110–150 kDa appears during metamorphosis. After this process, a definitive pattern of lectin staining and K⁺-stimulated, ouabain-sensitive p-nitrophenyl phosphatase activity is established.