Comparative Investigations of the Sandfish’s β-Keratin (Reptilia: Scincidae: Scincus scincus). Part 1: Surface and Molecular Examinations

Abstract

The Sandfish (Scincidae: Scincus Scincus) Is a Lizard Capable of Moving through Desert Sand in a Swimming-Like Fashion. the Epidermis of this Lizard Shows a High Resistance against Abrasion Together with a Low Friction to Sand as an Adaption to a Subterranean Life below the Desert’s Surface, Outperforming even Steel. the Low Friction Is Mainly Caused by Chemical Composition of the Scales, which Consist of Glycosylated β-Keratins. in this Study, the Friction, the Micro-Structure, the Glycosylation of the β-Keratin Proteins and β-Keratin Coding DNA of the Sandfish in Comparison to other Reptilian Species Was Investigated, Mainly with the Closely Related Berber Skink (Scincidae: Eumeces Schneideri) and another Sand Swimming Species, the Not Closer Related Shovel-Snouted Lizard (Lacertidae: Meroles Anchietae). Glycosylated β-Keratins of the Sandfish, Visualized with Different Lectins Resulted in O-Linked Glycans through PNA Employed as Carbohydrate Marker. Furthermore, the Glycosylation of β-Keratins in Various Squamatean Species Was Investigated and All Species Tested Were Found Positive; however, it Seems Like both Sand Swimming Species Examined Have a much Stronger Glycosylation of their β-Keratins. in Order to Prove this Finding through a Genetic Foundation, DNA of a β-Keratin Coding Gene of the Sandfish Was Sequenced and Compared with a Homologue Gene of Eumeces Schneideri. by Comparison of the Protein Sequence, a Higher Abundance of O-Glycosylation Sites Was Found in the Sandfish (enabled through the Amino Acids Serine and Threonine), Giving Molecular Support for a Higher Glycosylation of the β-Keratins in this Species.