Saleuddin A S
Calcif Tissue Res. 1975 Sep 17;18(4):297-310. doi: 10.1007/BF02546248.
The ultrastructure of the cells involved in the formation of the periostracum in Helisoma duryi duryi is described. Two distinct types of periostracal cells can be recognized: light and dark. The Golgi complexes of the light cell are involved in the biogenesis of periostracal units which are extruded at the base of the periostracal groove. Here they align into a single row so as to form the membrane-like lamellar covering of the periostracum. While the secretions of the dark periostracal cells contribute to the initial component of the dark layer of the periostracum, the mantle edge gland cells are responsible for its thickening. The adult periostracum is about 2--3 mum thick and it consists of a single dark layer covered by a membrane-like lamellar structure.
描述了杜氏圆扁螺（Helisoma duryi duryi）中参与形成壳皮的细胞的超微结构。可识别出两种不同类型的壳皮细胞：浅色和深色。浅色细胞的高尔基体参与壳皮单元的生物合成，这些单元在壳皮沟底部被挤出。在这里，它们排列成单排，从而形成壳皮的膜状层状覆盖物。深色壳皮细胞的分泌物构成壳皮深色层的初始成分，而外套膜边缘腺细胞则负责其增厚。成年壳皮约2-3微米厚，由单个深色层和一个膜状层状结构覆盖。
