Structural and Immunocytochemical Characterization of Keratinization in Vertebrate Epidermis and Epidermal Derivatives

The review examined keratinization in vertebrate epidermis, noting differences between keratinization and cornification from fish to amniotes. Keratinization, involving keratin filament production, was common in fish and amphibians, while cornification, seen in amniotes, involved biochemical changes for a tougher corneous mass. It also explored dermal-epidermal interactions in forming skin derivatives like scales, feathers, and hairs, and compared hard keratins in amniotes. The review concluded that vertebrate epidermis evolution involved increased specialization and protein complexity, especially in land vertebrates.