Evolution of Hard Proteins in the Sauropsid Integument in Relation to the Cornification of Skin Derivatives in Amniotes
April 2009
in “
Journal of anatomy
”
beta-keratins integument cornification amniotes fibrous polymers filaments keratin-associated proteins KAPs lepidosaurian proteins chelonian proteins archosaurian proteins feathers scales mutations structural modifications keratins phylogenetic analysis genome sequencing hard proteins reptile skin bird skin skin derivatives evolutionary divergence common ancestor molecular evolution
TLDR Hard skin features like scales, feathers, and hair evolved through specific protein changes in different animal groups.
The study examined the evolution of hard proteins, particularly beta-keratins, in the integument of sauropsids (reptiles and birds) and their relation to the cornification process in amniotes. It found that beta-keratins in reptiles and birds form fibrous polymers and filaments, differing from the amorphous keratin-associated proteins (KAPs) in mammals. The research highlighted the evolutionary divergence between lepidosaurian and chelonian/archosaurian proteins, noting that the latter group shares a common ancestor. The study suggested that feathers evolved from scales through specific mutations and structural modifications in keratins, emphasizing the need for further phylogenetic analysis and genome sequencing to fully understand the molecular evolution of these proteins.