The Laevicaulis alte is a terrestrial, pulmonate slug. The ovotestis of the slugs comprises only one vitellogenic oocyte in each acinus. Ultrastructural features of the vitellogenesis and various yolk granules along with their different developing stages are described for the first time in the pulmonate slugs by a transmission electron microscope. Vitellogenesis accompanied by the autosynthetic and the heterosynthetic processes. Ooplasmic Golgi complex and rough endoplasmic reticulum are involved in autosynthesis, whereas endocytosis of microvillar process of the oolemma supports heterosynthesis of yolk bodies. The follicular cleft contains various secretory materials and glycogen granules, some of which are incorporated into the distal tips of the microvilli of the oolemma. In ooplasm, three types of yolk granules are discriminated morphologically. The Type-1 yolk granules are ovoid shaped, characterized by the presence of a well-developed axial band. The Type-2 yolk granules are oval-shaped filled with a uniform electron-dense matrix. The Type-3 yolk granules are circular and vacuolated, surrounded by few cisternae of the rough endoplasmic reticulum. Morphometric characteristics of the vitellogenic oocyte, follicle cells, and different yolk granules are noted. The number of yolk granules in the ooplasm of L. alte is compared to those of other pulmonate species in different habitats.

中文翻译：

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关于 Veronicellidae 蛞蝓中的卵黄生成和蛋黄颗粒的注意事项，Laevicaulis alte (Férussac, 1822)

Laevicaulis alte 是一种陆生的肺蛞蝓。蛞蝓的卵睾在每个腺泡中仅包含一个生卵白卵母细胞。透射电子显微镜首次在肺状蛞蝓中描述了卵黄生成和各种卵黄颗粒的超微结构特征及其不同的发育阶段。伴随自合成和异合成过程的卵黄生成。卵质高尔基复合体和粗面内质网参与自合成，而卵质微绒毛过程的内吞作用支持卵黄体的异质合成。滤泡裂隙含有各种分泌物质和糖原颗粒，其中一些并入卵膜微绒毛的远端。在卵质中，从形态上区分三种类型的蛋黄颗粒。1 型蛋黄颗粒呈卵圆形，其特征是存在发达的轴向带。2 型蛋黄颗粒呈椭圆形，填充有均匀的电子致密基质。3 型卵黄颗粒呈圆形空泡状，周围有少量粗面内质网池。记录了生卵白细胞、卵泡细胞和不同卵黄颗粒的形态特征。将 L. alte 卵质中的卵黄颗粒数量与不同栖息地的其他肺状物种的卵黄颗粒数量进行比较。被粗面内质网的少数水池包围。记录了生卵白细胞、卵泡细胞和不同卵黄颗粒的形态特征。将 L. alte 卵质中的卵黄颗粒数量与不同栖息地的其他肺状物种的卵黄颗粒数量进行比较。被粗面内质网的少数水池包围。记录了生卵白细胞、卵泡细胞和不同卵黄颗粒的形态特征。将 L. alte 卵质中的卵黄颗粒数量与不同栖息地的其他肺状物种的卵黄颗粒数量进行比较。