Beisser C J, Lemell P, Weisgram J
Department of Comparative Anatomy & Morphology, Institute of Zoology, University of Vienna, Austria.
Tissue Cell. 2001 Feb;33(1):63-71. doi: 10.1054/tice.2000.0156.
The ultrastructure of the dorsal lingual epithelium of the semi-aquatic West African mud turtle, Pelusios castaneus, is described. Our goal is to give additional information to previous studies of this species such as feeding pattern analysis and gross morphology. Tissue specimens were fixed in modified Karnovsky solution followed by osmium tetroxide, embedded in epoxy resin and observed using light and transmission electron microscopy. The dorsal tongue surface is covered with moderate papillae, which are coated by a stratified epithelium overlying a connective tissue core. Two epithelial regions can be differentiated, although differences are not very obvious: the apical area, where granular cells are more abundant than mucus cells, and the lateral area, where cell distribution is opposite. Within the epithelium, different layers are discernable on the basis of the cells' organelles, corresponding with a process of cell maturation and formation of different granules. These results together with data of previous studies of this species show that the ultrastructure of the lingual epithelium is similar to other turtles adapted to semi-aquatic environments; functional and morphological data indicate a generalist, being well but not highly adapted to feeding in an aquatic environment.
描述了半水生西非泥龟（Pelusios castaneus）舌背上皮的超微结构。我们的目标是为该物种先前的研究（如摄食模式分析和大体形态学）提供更多信息。组织样本先用改良的 Karnovsky 溶液固定，然后用四氧化锇处理，嵌入环氧树脂中，并使用光学显微镜和透射电子显微镜进行观察。舌背表面覆盖着中度乳头，其由覆盖在结缔组织核心上的复层上皮覆盖。尽管差异不是很明显，但可以区分出两个上皮区域：顶端区域，其中颗粒细胞比黏液细胞更丰富；以及外侧区域，细胞分布情况相反。在上皮细胞内，根据细胞的细胞器可以辨别出不同的层，这与细胞成熟过程和不同颗粒的形成相对应。这些结果与该物种先前研究的数据一起表明，舌上皮的超微结构与其他适应半水生环境的龟类相似；功能和形态学数据表明它是一种通才，能较好但并非高度适应在水生环境中摄食。
