Differentiation of transporting epithelial cells during development of animal organisms includes remodelling of apical and basal plasma membranes to increase the available surface for transport and formation of occluding junctions, which maintain a paracellular diffusion barrier. This study provides a detailed ultrastructural analysis of apical and basal plasma membrane remodelling and cell junction formation in hindgut cells during late embryonic and early postembryonic development of the crustacean Porcellio scaber. Hindgut cells in late-stage embryos are columnar with flat apical and basal plasma membranes. In early-stage marsupial mancae the hindgut cells begin to acquire their characteristic dome shape, the first apical membrane folding is evident and the septate junctions expand considerably, all changes being probably associated with the onset of active feeding. In postmarsupial mancae the apical labyrinth is further elaborated and the septate junctions are expanded. This coincides with the transition to an external environment and food sources. First basal infoldings appear in the anterior chamber of early-stage marsupial mancae, but in the papillate region they are mostly formed in postmarsupial mancae. In molting late-stage marsupial mancae, the plasma membrane acquires a topology characteristic of cuticle-producing arthropod epithelia and the septate junctions are considerably reduced.

中文翻译：

---

后肠细胞质膜和细胞连接的超微结构分化与Porcellio scaber的关键发育过渡同步。

在动物生物体发育过程中，运输上皮细胞的分化包括重塑根尖和基底质膜，以增加可利用的表面来运输和形成闭塞连接，从而维持细胞旁扩散屏障。这项研究提供了详细的超微结构分析，在甲壳动物Porcellio scaber的胚胎晚期和胚胎后早期发育过程中，后肠细胞的顶端和基底质膜重塑以及细胞连接形成。晚期胚胎中的后肠细胞呈圆柱状，顶端和基部质膜平坦。在有袋有早期的Mancae中，后肠细胞开始获得其特征性的穹顶形状，第一个顶膜折叠明显，并且前房连接明显扩展，所有变化都可能与主动进食的开始有关。在成年后的mancae中，根尖的迷宫被进一步细化，并且分隔的连接被扩大。这与向外部环境和食物来源的过渡相吻合。第一基部褶皱出现在早期有袋有袋动物的前房，但在乳头状区域，它们大多形成于有袋后的动物。在蜕皮后期有袋马鞭中，质膜具有表皮产生节肢动物上皮的拓扑特征，并且分隔的连接明显减少。第一基部褶皱出现在早期有袋有袋动物的前房，但在乳头状区域，它们大多形成于有袋后的动物。在蜕皮后期有袋马鞭中，质膜具有表皮产生节肢动物上皮的拓扑特征，并且分隔的连接明显减少。第一基部褶皱出现在早期有袋有袋动物的前房，但在乳头状区域，它们大多形成于有袋后的动物。在蜕皮后期有袋马鞭中，质膜具有表皮产生节肢动物上皮的拓扑特征，并且分隔的连接明显减少。