Determination of thick and thin fibres distribution in Sunda porcupine dorsal skin (Hystrix javanica) using Picrosirius red staining

Abstract

The complexity of the Sunda porcupine skin has become an important topic due to the unique characteristics of its quill follicles. The structure and chemical composition of the skin has affected many physiological and other conditions. Generally, quills are larger, stronger and stiffer than hair; therefore, the skin structure needs to adapt to support their physiology. The strength of the skin is determined by its collagen composition and arrangement; therefore, this study aims to analyse the composition and distribution of thick and thin fibres based on the specific characteristics of Sunda porcupine skin under polarized light using picrosirius red staining. The skin samples used were from the thoracodorsal and lumbosacral regions of eight Sunda porcupine adults. The histological staining was carried out using the picrosirius red method, while the samples were observed under a polarized light microscope and analysed with software. The results showed that the skin is composed of 36%–65% thick fibres, 20%–35% thin fibres and small amounts of other types with the lumbosacral region having higher compositions of thick and thin fibres than those in the thoracodorsal region. Furthermore, the thoracodorsal and lumbosacral regions have the highest composition of thick fibre in the deeper dermis and quill follicle, respectively. These demonstrated that the complexity of the skin structure of Sunda porcupine due to its quill derivates correlated with its collagen composition and distribution.

Preliminary examination of the histochemistry of the semitendinosus muscle microstructure in Bali cattle (Bos javanicus) and the correlations with muscle score

“…In picrosirius red staining, Type IV collagen and several glycoproteins and proteoglycans are the unpolarized components, which appeared dark or black under polarized light. This was also found in the basement membrane of the skin which was mostly composed of this collagen type (Junqueira et al., 1979; Montes & Junqueira, 1991; Prawira et al., 2022). Furthermore, thick fibre and thin fibre are also observed in the endomysium of the semitendinous muscle of Bali cattle.…”

“…The observation under a polarized light filter was conducted following the method described by Prawira et al. (2022) using a modified microscope with a linear polarized filter. The parameters observed included myofibril cross‐sectional area, sarcomere length, the relative percentage of intramuscular collagen and fibre type identification.…”

Morphological investigation of intestine structure of the Sunda Porcupine (Hystrix javanica)

“…There is also no published study about the intestinal structure, but that of its distant relatives, such as the African porcupine (Hystrix africaeaustralis), has been studied by van Jaarsveld (1983), andvan Jaarsveld andKnight-Eloff (1984). Apart from its special skin characteristics due to the quill (Prawira et al 2018(Prawira et al , 2019(Prawira et al , 2022, the digestive system of Sunda porcupine needs to be studied to identify the morphological adaptation to the feeding diet. Therefore, this study aims to investigate the intestinal structure of the Sunda porcupine as an important part of its digestive system.…”