Invertebrate Zoology Department, Biological Faculty, M. V. Lomonosov Moscow State University, Moscow, Russia.
Department of Natural Sciences, National Museum of Wales, Cathays Park, Cardiff, UK.
J Morphol. 2022 Mar;283(3):363-373. doi: 10.1002/jmor.21448. Epub 2022 Jan 19.
The rhipidoglossan radula, consisting of numerous teeth in each transverse row, is characteristic of phylogenetically distant groups of gastropods, including Vetigastropoda, Neritimorpha and 'lower' Heterobranchia. Previous studies have revealed the main patterns in the formation of the rhipidoglossan radula of vetigastropods, the main feature of which is the division of the formation zone into two horns, where marginal teeth are formed by a multilayered epithelium (odontoblasts). This work is devoted to the study of the formation of the rhipidoglossan radula of Nerita litterata using light and electron microscopy. The data obtained show that, despite the different external morphology of the radular sac of neritids and vetigastropods, the radular sac of N. litterata, like that of vetigastropods, is divided into two parts, in which the marginal teeth are similarly formed by odontoblasts located in more than one layer. It seems probable that this complex, three-dimensional structure of the formation zone is associated with a broad radula with numerous elongate marginal teeth and could be characteristic of other gastropods with this type of radula. Additional supporting rods located along the odontoblasts and consisting of vacuolated cells were first discovered in Nerita.
栉舌螺类的齿舌由每横排的许多牙齿组成，是包括扭舌目、笠贝目和“低等”异腹足类在内的进化上相距甚远的腹足纲群体的特征。先前的研究揭示了扭舌目腹足类栉舌齿舌形成的主要模式，其主要特征是形成区分为两个角，边缘齿由多层上皮（成牙质细胞）形成。本工作致力于使用光镜和电子显微镜研究荔枝螺栉舌齿舌的形成。所得数据表明，尽管笠贝目和扭舌目腹足类的齿舌囊具有不同的外部形态，但荔枝螺的齿舌囊与扭舌目腹足类一样，分为两部分，其中边缘齿同样由位于多层的成牙质细胞形成。这种形成区的复杂的三维结构可能与具有大量长形边缘齿的宽齿舌有关，并且可能是具有这种类型齿舌的其他腹足类的特征。在笠贝目中首次发现了沿成牙质细胞排列并由空泡细胞组成的附加支持棒。
