Immunocytochemical and electrophoretic distribution of cytokeratins in the regenerating epidermis of the lizardPodarcis muralis

Abstract

Using immunocytochemistry at light‐ and electron‐microscope levels, we studied the distribution of three monoclonal antibodies (AE1, AE2, AE3) specific for mammalian α‐keratins in regenerating lizard epidermis. We also characterized the keratins expressed during this process by immunoblotting after electrophoretic separation. The AE1 antibody is localized in the basal and suprabasal layers of prescaling and scaling epidermis. During the first stages of scale neogenesis, the AE1 antibody also marks the differentiating oberhautchen and β‐layer, but it disappears from these layers as they mature. This antibody does not stain the prekeratinized and keratinized outermost layers in the hinge region. The AE2 antibody labels the superficial wound epidermis, prekeratinizing and keratinized β‐ and α‐layers, but not basal and suprabasal cells. The AE3 antibody labels all living and keratinized epidermal layers, although AE3 immunoreactivity decreases and disappears as the β‐layer matures. The ultrastructural study shows that the AE2 and AE3, but not the AE1, antibodies specifically label small electron‐dense areas within the β‐layer, suggesting retention of α‐keratins. In the stages of tail regeneration examined, immunoblotting with the three antibodies used for the immunolocalization gives a pattern similar to that of the normal epidermis, except distally, where the process of scale differentiation begins. In this region, in addition to the keratin forms discovered in the normal and in proximal regenerating epidermis, an intense low molecular weight band at 40–41 kDa, positive to all three antibodies, is clearly detectable. Furthermore, in the distal region AE1 and AE3 antibodies, but not the AE2, recognize a weak band at 77–78 kDa not present in the normal and proximal epidermis. The localization and the possible role of the different keratins in the regenerating epidermis is discussed. J. Morphol. 246:179–191, 2000. © 2000 Wiley‐Liss, Inc.

Nucleolar structure across evolution: The transition between bi- and tricompartmentalized nucleoli lies within the class Reptilia

“…Fragments of small intestine and stomach from an adult Nile crocodile were provided by Dr. Mc Milinkovitch (Université libre de Bruxelles, Belgium). The epidermis of different other reptilian species were also examined: the turtle (Emydura macquarri, Gray 1831, Chelidae) (Alibardi and Thompson, 1999), the lizards (Podarcis muralis, Laurenti 1768, Lacertidae and Anguis fragilis, Linnaes 1758, Anguidae) (Alibardi et al, 2000), the snakes (Liasius fuscus, Peters 1873, Pythonidae and Natrix natrix, Linnaes 1758, Colubridae) (Alibardi and Thompson, 2003;Alibardi, 2005) and the crocodile (Alligator mississippiensis, Daudin 1801, Alligatoridae) (Alibardi and Thompson, 2001).…”

Formation of the corneous layer in the epidermis of the tuatara (Sphenodon punctatus, Sphenodontida, Lepidosauria, Reptilia)

“…In lizards, keratins connected with alpha-keratinization have a molecular weight of 61-68 kDa (Carver and Sawyer 1987;Alibardi et al 2000Alibardi et al , 2001. Very likely, keratins of low molecular weight (50, K14, acidic AE1-positive, or 58, K5, basic AE3-positive) are present in the basal layers of the epidermis of S. punctatus.…”

Effect of polyglycolic acid sheets with fibrin glue (MCFP technique) on the healing of wounds after partial resection of the border of the tongue in rabbits: a preliminary study

“…Since cells of the upper basal layer express AE1/AE3 in the epithelialization phase of wound healing, AE1/AE3 was used as a marker for evaluating epithelialization 8 . FGF-2 was used as a marker for evaluating the degree of granulation and wound healing by fibroblast proliferation 23,24 .…”