Wittmer Carolin, Nowack Christine
Department of Zoology, Institute for Biology, University of Kassel, Heinrich-Plett-Straße 40, Kassel, 34132, Germany.
Department of Cell Biology, Institute for Biology, University of Kassel, Heinrich-Plett-Straße 40, Kassel, 34132, Germany.
J Morphol. 2017 Jun;278(6):791-800. doi: 10.1002/jmor.20673. Epub 2017 Mar 23.
African lungfish (Protopterus) seem unique among osteognathostomes in possessing a potential vomeronasal organ homolog in form of accessory epithelial crypts within their nasal cavity. Many details regarding structural and functional properties of these crypts are still unexplored. In this study, we reinvestigate the issue and also present the first data on epithelial crypts in the South American lungfish Lepidosiren paradoxa. The nasal cavities of L. paradoxa and Protopterus annectens were studied using histology, scanning electron microscopy, and alcian blue and PAS staining. In both species, the epithelial crypts consist of a pseudostratified sensory epithelium and a monolayer of elongated glandular cells, in accordance with previously published data on Protopterus. In addition, we found a new second and anatomically distinct type of mucous cell within the duct leading into the crypt. These glandular duct cells are PAS positive, whereas the elongated glandular cells are stainable with alcian blue, suggesting distinct functions of their respective secretions. Furthermore, the two lungfish species show differently structured crypt sensory epithelia and external crypt morphology, with conspicuous bilaterally symmetrical stripes of ciliated cells in L. paradoxa. Taken together, our data suggest that stimulus transport into the crypts involves both ciliary movement and odorant binding mucus.
非洲肺鱼（原鳍鱼属）在硬骨有颌类动物中似乎独一无二，其鼻腔内存在一种潜在的犁鼻器同源物，表现为副上皮隐窝的形式。关于这些隐窝的结构和功能特性的许多细节仍未被探索。在本研究中，我们重新研究了这个问题，并首次展示了南美肺鱼——南美长肺鱼的上皮隐窝的数据。使用组织学、扫描电子显微镜以及阿尔新蓝和过碘酸希夫染色法对南美长肺鱼和非洲肺鱼的鼻腔进行了研究。与之前发表的关于非洲肺鱼的数据一致，在这两个物种中，上皮隐窝均由假复层感觉上皮和单层细长的腺细胞组成。此外，我们在通向隐窝的导管内发现了一种新的、在解剖学上不同的第二种黏液细胞类型。这些腺导管细胞对过碘酸希夫染色呈阳性，而细长的腺细胞可被阿尔新蓝染色，这表明它们各自分泌物具有不同的功能。此外，这两种肺鱼的隐窝感觉上皮结构和隐窝外部形态不同，南美长肺鱼有明显的双侧对称的纤毛细胞条纹。综上所述，我们的数据表明，刺激物进入隐窝涉及纤毛运动和与气味剂结合的黏液。
