Developmental changes in the heterocellular epidermis of Pelobates syriacus integument

Changes in characteristic components of the skin epidermis of the large tadpole of Pelobates syriacus were studied throughout its development. The fate of two specific cells in the skin epidermis was followed, from the young tadpole to the adult was studied. It was found that flask-shaped type cells in the tadpole epidermis which are PAS-positive, stain with peanut lectin (PNA). There is no detectable band 3 in the premetamorphosed stages, and mitochondria-rich cells are very rare. This pattern of staining changes completely upon metamorphosis: the PAS-positive cells, specific to the tadpole epidermis disappear, and the mitochondria-rich (MR) cells in the adult skin epithelium react with polyclonal anti-band 3 antibody. Western blot analysis showed the presence of a band 3-like protein of about 95 kDa, only in the adult epithelial extract, corroborating the immunocytochemical observations. The finding of the presence of band 3-like protein in the MR cells of Pelobates, is similar to the observations made in the skin of other amphibian species. On the other hand, the binding of peanut lectin to MR cells is species-specific, since it does not react with the MR cells in the skin epithelium of Pelobates syriacus.