Adhesive pads of gecko and anoline lizards utilize corneous and cytoskeletal proteins for setae development and renewal
- 5 July 2020
- journal article
- research article
- Published by Wiley in Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
- Vol. 334 (5) , 263-279
Abstract
The formation of the complex pattern of setae in adhesive pads of geckos and anoline lizards has been analyzed by ultrastructural, autoradiographic, and immunohistochemical methods. Setae terminate with spatulated ends responsible for adhesion that allow these lizards to climb vertical substrates and conquer arboreal niches. Setae derive from a complex interfaced molding between two specialized epidermal layers of the shedding complex that determines the cyclical skin molting, Oberhautchen and clear layers. Setae result from the action of setae cytoskeleton and the surrounding cytoplasm of clear cells. An intense protein synthesis, indicated by histidine and proline autoradiography, takes place during setae formation. Corneous and cytoskeletal proteins such as beta‐proteins (CBPs), intermediate filament keratins (IFKs), actin, RhoV, tubulin, plakophilin‐1, are produced during setae formation. Microfilaments of actin and microtubules of tubulin grow inside the elongating setae. Microtubules associated with filaments of unknown IKFs are produced in the cytoplasm of clear cells, forming a helical cytoskeleton that surrounds the growing setae. Oberhautchen and clear cells are tightly joined by numerous desmosomes and plakophilin‐1 is mainly localized along the perimeter of these cells. These observations suggest that actin and tubulin are present in a dynamic form in the forming setae and in the surrounding cytoplasm of clear cells. Aside the localized micro‐deformations of the cell membranes leading to setae formation the cytoskeleton determines the accumulation of CBPs inside the growing setae and the spatula. How the genome determines the specific pattern of cytoskeletal organization with the resulting species‐specific setae branching remains unknown.Keywords
Funding Information
- self-supported research
This publication has 38 references indexed in Scilit:
- Immunolabelling for RhoV and actin in early regenerating tail of the lizard Podarcis muralis suggests involvement in epithelial and mesenchymal cell motilityActa Zoologica, 2019
- Immunolocalization of keratin‐associated beta‐proteins in developing epidermis of lizard suggests that adhesive setae contain glycine–cysteine‐rich proteinsJournal of Morphology, 2012
- Cornification in reptilian epidermis occurs through the deposition of keratin‐associated beta‐proteins (beta‐keratins) onto a scaffold of intermediate filament keratinsJournal of Morphology, 2012
- Histochemical and ultrastructural analyses of adhesive setae of lizards indicate that they contain lipids in addition to keratinsJournal of Morphology, 2011
- Cell biology of adhesive setae in gecko lizardsZoology, 2009
- Expression of beta‐keratin mRNAs and proline uptake in epidermal cells of growing scales and pad lamellae of gecko lizardsJournal of Anatomy, 2007
- Distribution and characterization of proteins associated with cornification in the epidermis of gecko lizardTissue and Cell, 2005
- Ultrastructural autoradiographic and immunocytochemical analysis of setae formation and keratinization in the digital pads of the gecko Hemidactylus turcicus (Gekkonidae, Reptilia)Tissue and Cell, 2003
- Observations on the histochemistry and ultrastructure of the epidermis of the tuatara, Sphenodon punctatus (Sphenodontida, Lepidosauria, Reptilia): A contribution to an understanding of the lepidosaurian epidermal generation and the evolutionary origin of the squamate shedding complexJournal of Morphology, 2003
- Keratohyalin-like granules in embryonic and regenerating epidermis of lizards and Sphenodon punctatus (Reptilia, Lepidosauria)Amphibia-Reptilia, 1999