Use of the cryostat to prepare slides for trichological analysis / [Uso do aparelho criostato para preparação de lâminas para a análise tricológica]

A análise dos padrões morfológicos e morfométricos das microestruturas capilares é uma técnica não invasiva que pode ser utilizada para identificar espécies de mamíferos. Esta técnica pode ser aplicada em diversas áreas da ciência animal, tais como controle de qualidade de alimentos e análises forenses. Dada a dificuldade de obter seções transversais de pelos de guarda para expor o córtex, a maioria dos estudos analisou apenas os componentes medulares e cuticulares do pelo. A inclusão do córtex capilar de guarda em uma análise tricológica pode proporcionar uma descrição mais precisa das raças ou espécies de mamíferos. O presente estudo propõe um novo método para a execução de cortes transversais que expõem o córtex do pelo guarda de mamíferos utilizando um criostato.(AU)

Structure, morphology and composition of fur on different parts of reindeer (Rangifer Tarandus) foot.

In the long-distance migration of reindeer in winter, furs of reindeer foot, as the part in direct contacting with the external environment, can play the role of protection and heat preservation. With furs on different parts of the right posterior foot (fibular side, tibial side and planta pedis) as research objects, the microstructure of reindeer foot furs was observed with a scanning electron microscope. The image displayed that the reindeer foot furs was divided into 3 layers, namely cuticular layer, cortical layer and medulla layer. It was observed from the fur surface that the scales of fur on tibial side had smooth edge, with the scale structure in mosaic and coronary types. The scale structure of furs on the other parts showed the irregular waves due to abrasion to different degrees. From the cross-section view of fur, there was a non-medullated segment on the medial part of fur on planta pedis. The medulla layer of fibular and tibial sides showed a porous foam structure. The medulla index (MI) of fur on fibular side and tibial side at distal part was 70.35% and 81.79%, respectively, and MI at medial part was 77.88% and 88.08%. The composition of reindeer foot fur was measured through infrared spectroscopy and energy spectrum analysis respectively. The element contents of foot fur varied on different parts. The content of sulfur of the furs on planta pedis was higher than that on other parts. The research results can provide foundations for the functional study and bionic design of reindeer foot furs during long distance migration and swimming.