Comparative ultrastructural‐functional characterizations of the skin in three reptile species; Chalcides ocellatus, Uromastyx aegyptia aegyptia, and Psammophis schokari aegyptia (FORSKAL, 1775): Adaptive strategies to their habitat

Abstract

The current investigation was planned utilizing SEM, histological, and furthermore cytokeratin immunohistochemical to give a full depiction of skin of three reptiles species; Chalcides ocellatus (Scincidae), Uromastyx aegyptia aegyptia (Agamidae), and Psammophis schokari aegyptia (Colubridae) captured from Egypt with various ecological environment. Our SEM results showed different scales covered epidermis of three reptile's species with diverse surface microstructure. Overlapped rhomboid scales with numerous lenticular sense organs with numerous pores and oberhäutchen layer with microridges in C. ocellatus. In U. aegyptia, scales were overlapped elliptical‐shaped possess lens‐like sense structure with several scattered pits and oberhäutchen layer with polygonal outlined cells. While in P. schokari aegyptia, smooth scales flattened with two large dome‐shaped scale receptors/sensilla and lens‐like sense structure, moreover polygonal‐shaped micro‐ornamentation in scale hinge joints were observed. Histologically, skin of three species had outer epidermis with stratum germinativum, stratum corneum (α‐keratin, β‐keratin layer) capped by surface Oberhäutchen and inner dermis. Osteoderms were observed with dermis of C. ocellatus. There are marked variation within pigment cells types among examined species. Melanophores observed in dermal layer of C. ocellatus, while in U. aegyptia, three pigment cells in tegument dermis; melanophores, xanthophores, and iridophores whereas, P. schokari aegyptia had two forms of chromatophore cells (melanophores and iridophores) in dermis and few melanophores scattered between stratum germinativum cells. The highest cytokeratin immunostaining observed in epidermal cell layer of U. aegyptia aegyptia than two other species. Conclusion, dry scaly skin of reptiles reflects a great range of functional aspects and success to adapt with terrestrial life.

Snout cutis of the domestic pig (Sus scrofa domesticus, Linnaeus, 1758): Using light and transmission electron microscopy

“…Following the fixation, the samples were fixed at 1% osmium tetroxide (OsO 4 ), then dehydrated in a graded dilution of absolute ethanol (Aboelnour, Noreldin, Massoud, & Abumandour, 2020; Kandyel et al, 2021). After that, samples were embedded in epoxy resin.…”

“…The terrestrial mammalian skin is described as a protective barrier between the animals and surrounding environmental conditions and have skin have numerous environmental adaptations according to multiple environmental factors such as dryness, aging, position, and gender (Bazm, Goodarzi, Abumandour, Naseri, & Hosseinipour, 2020; Kandyel, Elwan, Abumandour, & El Nahass, 2021; Thomas, 2005; Zaki, 2015), in addition to the skin has several functions such as sensation and protection (Gawronska‐Kozak & Bukowska, 2014). The skin is viewed as the biggest organ of the body that has different functions fulfills a few capacities (Gawronska‐Kozak & Bukowska, 2014).…”

A histological and immunohistochemical study on the parabronchial epithelium of the domestic fowl's (Gallus gallus domesticus) lung with special reference to its scanning and transmission electron microscopic characteristics

“…Fresh lungs from three adults healthy domestic fowl ( G. gallus domesticus ) were fixed in 2.5% glutaraldehyde for 24 hr, rinsed in 0.1 M cacodylate buffer at pH 7.4, then post‐fixed for 1 hr at room temperature with 1% osmium tetroxide. Samples were dehydrated with ethyl alcohol in a graded sequence and eventually embedded in epoxy resin (Kandyel, Elwan, Abumandour, & El Nahass, 2021). For tissue examination, semithin sections were cut and stained with toluidine blue.…”

Microscopic focus on ependymal cells of the spinal cord of the one‐humped camel (Camelus dromedarius): Histological, immunohistochemical, and transmission microscopic study

“…After the initial fixation, the tissues were washed in several changes of cold 0.1 M phosphate every 15 min for 2 hr at 4 C. Then, the tissues were postfixed in 1% solution of phosphate-buffered osmium tetroxide (2% osmic acid 5 ml and phosphate-buffer 5 ml) for 2 hr at room temperature. Samples were rapidly dehydrated through ethyl alcohol in a graded sequence (30, 50, 70, 90, and 100% for two changes) for 30 min in each and eventually embedded in epoxy resin (Hayat, 1986;Kandyel, Elwan, Abumandour, & El Nahass, 2021). Then transferred to propylene oxide and placed overnight in a 1:1 mixture of propylene oxide and Epoxy Araldite.…”