Comparative analysis of the different regions of skin tissue in Nannospalax xanthodon

Abstract

Blind mole rats (Nannospalax xanthodon Palmer, 1903) are subterranean mammals that are wellknown for their high tolerance to hypoxia and resistance to cancer. Due to their unusual habitat, these animals have developed several adaptations during their evolution. Therefore, this study aimed to identify possible structural differences between different regions of the skin in Nannospalax as well as to characterize the histological organization of a specialized skin patch namely scrub sensory organ that have possibly arisen as a result of adaptation to underground life. Skin from the neck, nasal pad and the scrub sensory organ was harvested from wildtype blind mole rats and fixed in 10% formaldehyde. Tissues were embedded into paraffin and blocked via routine histological procedures. 5-micron sections were taken and stained with Hematoxylin & Eosin and Cresyl Violet. Histopathological analysis of the skin revealed that the nasal pad and the scrub sensory organ were significantly thicker compared to the neck skin. Skin epithelia was structurally normal, although it was thicker in the neck skin in comparison to others. We observed structures that are similar to pyramidal cells in the scrub sensory organ. In conclusion, we defined some histological properties of the scrub sensory organ in Nannospalax xanthodon for the first time in the literature. Specifically, the detection of structures that are similar to pyramidal cells is significant. These results indicate structural differences between different skin regions and suggest a role for the scrub sensory organ in somatosensation.

The double skin of the pink fairy armadillo, the peculiar integumentary system of Chlamyphorus truncatus Cingulata (Mammalia, Xenarthra)

“…10c and Krmpotic et al, 2012). The body is covered by abundant, fine and soft fur, which has characteristics similar to those of other mammals that are almost completely adapted to underground life (Daly & Buffenstein, 1998;Kimani, 2013;Klauer et al, 1997;Sokolov, 1982;S€ ut et al, 2020;Sweet, 1907). In a previous study of Spalax ehrenbergi, it was argued that the tufts of fine hairs can probably bend in different directions, representing an adaptation to locomotion in burrows (Klauer , 1997).…”

“…Therefore, underground mammals must be influenced by physical and biotic tensions of the underground ecotope at all levels of organization. In the particular case of the integumentary system (a multifunctional system that establishes a protective physical interface between the organism and the surrounding environment and provides a mechanical, physiological and immunological barrier), morphological and physiological traits have evolved as adaptations to a subterranean lifestyle, but only in very few fossorial or subterranean species has the integumentary system been studied (e.g., Daly & Buffenstein, 1998; Kimani, 2013; Klauer et al., 1997; Menon et al., 2019; Sokolov, 1982; Süt et al., 2020; Sweet, 1907). Additionally, the burrowing subterranean lifestyle, despite being linked to a system of simple tunnels, exposes the integument of the specimens to continuous abrasion and friction against a physically dense (and often siliceous) sediment that opposes locomotion.…”