金乌贼成体副缠卵腺的超显微结构

Ultrastructure of the Accessory Nidamental Gland of Adult Sepia esculenta

中文关键词: 金乌贼  副缠卵腺  超显微结构  共生菌

英文关键词: Golden cuttlefish (Sepia esculenta)  Accessory nidamental gland  Ultrastructure  Symbiotic bacteria

中文摘要:

      采用组织学和电镜技术对金乌贼(Sepia esculenta)成体副缠卵腺的结构进行了研究。结果显示，(1)解剖结构显示，副缠卵腺呈耳状，下端呈‘M’型与缠卵腺紧密连接，颜色为白色并夹杂着橙黄色；(2)显微结构显示，副缠卵腺由腺壁、腺体小管和结缔组织构成，腺壁由外向内依次为外膜层和肌肉层，其中，外膜层由单层柱状上皮细胞组成；腺体小管数量较多，平均直径为70 μm，内腔表面可见微绒毛层，管腔内含有大量的分泌物质；结缔组织具有集中分布的血管和肌肉纤维；(3)超微结构显示，上皮细胞细胞质中含有数量较多且分布集中的囊泡，部分囊泡中含有分泌球状体；微绒毛分布面积较广且排列密集，而纤毛一部分集中分布，另一部分呈单行排列，着生不连续；腺体小管管腔内具有大量的共生菌，绝大部分为球菌，且在管腔中具有较多的分泌球状体。研究表明，金乌贼副缠卵腺是一种起分泌作用的腺体，存在的共生菌据认为在胚胎发育阶段的病害防治方面具有一定作用。

英文摘要:

      The accessory nidamental gland (ANG) is a type of accessory gland found in Sepioidea species. It is an important part of the female reproductive system and plays an important role in the formation of the egg membrane, disease control, and buoyancy adjustment. Here, the ultrastructure of the ANG from adult Sepia esculenta was studied using light and electron microscopy. The results showed that the ANG forms an ear-like shape; its bottom forms an ‘M’ shape, which is closely attached to the nidamental gland; and the color is white and orange. ANG is composed of a gland wall, tubules, and connective tissue. The inside layer is muscular, whereas the outer layer is composed of simple columnar epithelium cells. A number of tubules were observed with an average diameter of 70 μm; the lumen surface has a microvilli layer, and a large number of substances are secreted inside the lumen. The connective tissue contains concentrated distributions of blood vessels and muscle fibers. The cytoplasm of the epithelial cells contains many concentrated distributed vesicles, and some contain secretion globules. The microvilli are widely distributed; while the cilia are discontinuous, with some concentrated and others arranged in a single line. The tubule lumens contained a large number of symbiotic bacteria, most of which were coccoid-shaped bacteria, containing many secretion globules. Consequently, the ANG of S. esculenta possesses secretory function; the existence of symbiotic bacteria in the ANG might play an important role in disease resistance during embryonic development. We show the ultrastructure of the ANG in adult S. esculenta and discuss its function and role in reproduction. The aim is to reveal the breeding strategies of S. esculenta and to enrich knowledge of the reproductive biology of cephalopods, thus, providing a reference for optimization of S. esculenta breeding technology.