Distribution patterns of cytokeratins in epidermis and horny teeth of the adult sea lamprey, Petromyzon marinus.

An immunohistochemical characterization of cytokeratins in the skin tissues of the sea lamprey, Petromyzon Marinus was performed using a panel of monoclonal antibodies. Cytokeratins typical for simple epithelia have been detected in the epithelial cells, with a 8/18 pair expression. Granular cells and skein cells showed a labelling of cytokeratins 7, 8, 18 and 19, that is observed also in the non-keratinized layers of the horny teeth. Similar cytokeratins occur in the outermost cell layers of the epidermis; cytokeratin 19 shows a comparatively weaker reaction. These results suggest that the cytokeratin patterns in the above types of cells of adult epidermis are quite different from those in ammocoetes where the expression of cell specific cytokeratins may be correlated with specific programs of epidermal differentiation.