von Byern Janek, Cyran Norbert, Klepal Waltraud, Rudoll Livia, Suppan Johannes, Greistorfer Sophie
Faculty of Life Science, Core Facility Cell Imaging and Ultrastructure Research, University of Vienna, Vienna, Austria.
Ludwig Boltzmann Institute for Experimental and Clinical Traumatology, Austrian Cluster for Tissue Regeneration, AUVA Research Center, Vienna, Austria.
J Morphol. 2018 Feb;279(2):187-198. doi: 10.1002/jmor.20763. Epub 2017 Nov 3.
Although gastropods have been crawling through the ocean and on the land for 60 million years, we still know very little about the sticky mucus produced in their foot. Most research has been focused on marine species in particular and, to a lesser extent, on the well-known terrestrial species Arion vulgaris and Cornu aspersum. Within this study, we aim to characterize the foot anatomy of a smaller representative of the family Helicidae, the banded snail Cepaea hortensis. We are particularly interested in the microanatomy of the foot glands, their position, and the histochemical nature of their secretory content. Characterization of the dorsal foot region of Cepaea hortensis reveals four glands, differing in their size and in the granules produced. Histochemically, three of them react positively for sugars (PAS staining and lectin affinity tests for mannose, glucose and N-acetyl-d-glucosamine) and acidic proteins (positive Alcian blue and Toluidine blue staining), indicating the presence of acidic glycosaminoglycans. The fourth gland type does not react to any of these dyes. The ventral pedal region includes two different gland types, which are positive for the presence of acidic glycoproteins, with a lectin affinity for mannose only. A comparison with Helix pomatia indicates differences regarding the number of glands and their contents. In Helix, only three gland types are described in the dorsal region of the foot, which show a similar granular appearance but nevertheless differ in their chemical composition. Congruently, there are two gland types in the ventral region in both species, whereas in Helix an additional sugar moiety is found. This raises the question whether these differences between the pedal glandular systems of both helicid species are the result of protection or size-related adaptations, as they occur in the same habitat.
尽管腹足纲动物已经在海洋和陆地上爬行6000万年了，但我们对它们足部产生的粘性黏液仍然知之甚少。大多数研究都特别关注海洋物种，在较小程度上关注著名的陆生物种——欧洲蛞蝓和庭院蜗牛。在本研究中，我们旨在描述旋螺科一个较小代表种——带状蜗牛（Cepaea hortensis）足部的解剖结构。我们特别感兴趣的是足部腺体的微观解剖结构、它们的位置以及其分泌内容物的组织化学性质。对带状蜗牛足部背侧区域的特征描述揭示了四种腺体，它们在大小和产生的颗粒方面存在差异。组织化学分析表明，其中三种腺体对糖类（过碘酸希夫染色以及针对甘露糖、葡萄糖和N - 乙酰 - d - 葡萄糖胺的凝集素亲和力测试）和酸性蛋白质（阿尔辛蓝和甲苯胺蓝染色呈阳性）呈阳性反应，表明存在酸性糖胺聚糖。第四种腺体类型对这些染料均无反应。腹侧足部区域包括两种不同的腺体类型，它们对酸性糖蛋白呈阳性反应，仅对甘露糖有凝集素亲和力。与苹果蜗牛（Helix pomatia）的比较表明，在腺体数量及其内容物方面存在差异。在苹果蜗牛中，足部背侧区域仅描述了三种腺体类型，它们呈现出相似的颗粒外观，但化学成分不同。同样，两个物种的腹侧区域都有两种腺体类型，而在苹果蜗牛中还发现了一种额外的糖部分。这就提出了一个问题，即这两种旋螺科物种的足部腺体系统之间的这些差异是保护作用的结果还是与大小相关的适应性变化，因为它们生活在相同的栖息地。
