Demonstration of substances of innate immunity in the integument of the Malayan pangolin (Manis javanica)

Abstract

Using immunohistochemistry, the study demonstrates substances of the innate immunity in the skin of the Malayan pangolin (Manis javanica), referring mainly to the epidermis. The results obtained showed clear reaction differences between the dorsolateral body region with its strong cover of hard horny scales and the abdominal body part with a thick soft stratum corneum and a dense cover of fine hairs. Regarding pathogen recognition receptors, positive reactions for Toll-like receptors were generally weak for TLR2, in contrast to TLR4, that exhibited strong reactions in the epidermis of both body regions, with increasing staining intensities towards the stratum corneum; ß-glucan receptors showed positive reactions only for Lficolin and mannose-binding lectin, but not for dectin-1, and only at the abdomen. A generally positive staining for both body regions was obtained for all cationic antimicrobial peptides tested, whereby cathelicidin exhibited strong reaction intensities in all epidermal layers, ß-defensin 2 staining was often limited to the stratum basale and the stratum spinosum, and positive reactions for ß-defensin 3 appeared distinctly only in the epidermis of the abdomen; for these peptides, positive reaction staining could also be found in the outer epithelial root sheath of hair follicles, their glandular annexes, and free cells of the dermis. Lysozyme was found in the vital epidermis of both body regions studied, with strong staining limited to the dorsum; strong reactions were also visible in the hair follicles.

Development of the integument of Dasypus hybridus and Chaetophractus vellerosus, and asynchronous events with respect to the postcranium

“…Elastic fibers are scarce in the dorsal integument and proportionally more abundant in the ventral skin of both species. This result agrees with those found in fetuses of Dasypus novemcinctus (Vickaryous and Hall 2006), pangolins (Meyer et al 2010), and reptiles with osteoderms (Vickaryous and Hall 2008), which demonstrates that the absence of these fibers is related to dermal rigidness.…”

Immunohistochemical demonstration of keratins in the epidermal layers of the Malayan pangolin (Manis javanica), with remarks on the evolution of the integumental scale armour

“…As already shown earlier, 5 the integument of the pangolin is characterized by distinct regional differences comparing the dorsolateral body region, marked by a very hard scaly armour, with the abdominal body region without scales, but with a thick soft stratum corneum . This difference includes a polished surface of the hard scales (Figure 1a), in contrast to the surface of the epidermis of the abdomen, which is only protected by a dense and fine hair coat (Figure 1b).…”

“…1,2 Especially rather small groups like the order Pholidota with the only family Manidae are concerned, that consists of one genus ( Manis ) with eight species and has a special biology. 3,4 The physical appearance of pangolins is based on large, hardened, plate-like scales found dorsolaterally at the body and the tail, whereas the abdominal body part shows a thick soft stratum corneum and a dense cover of fine hairs 5 . These scales, which are soft on newborn pangolins but harden as the animal matures, are formed by α-keratins and β-keratins, 6,7 guaranteeing a high abrasive wear resistance 8 .…”

Untitled

“…Penelitian tentang trenggiling sangat terbatas, beberapa penelitian dasar yang telah dilaporkan adalah mengenai taksonomi, chormosom, dan sangat sedikit mengenai molekuler, persebaran dan ekologi. Semua penelitian tentang trenggiling tersebut lebih memfokuskan pada jenis yang tidak berasal dari Indonesia (Munyala et al, 2008;Nie et al, 2011;Meyer et al, 2010;Gaudin dan Wible, 1999).…”