Follicle cell processes (FCP) are actin-based, tube-like structures that connect the developing oocyte to the follicle cells throughout oogenesis. They were first described in Selachians (sharks) where their suggested roles were facilitating the transport of metabolites to the developing oocyte and providing structural support to the large egg cells of sharks, an early stage in the evolution of viviparity. Subsequent studies found that FCP are absent in Rajiformes (skates) suggesting that FCP may have been novel structures specific to the sharks. Here, we described FCP in Hydrolagus colliei, a Chimaeriform. The FCP of H. colliei differ morphologically from those previously described in sharks but as they also contain actin, they presumably play similar roles provisioning the developing oocyte and providing structural support. The presence of FCP in the order Chimaeriformes suggest their origin predates the split of the Elasmobranchs and the Holocephalans. This article is protected by copyright. All rights reserved.

中文翻译：

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Hydrolagus colliei 卵巢卵泡内的管状结构表明卵泡细胞过程的早期起源

卵泡细胞过程 (FCP) 是基于肌动蛋白的管状结构，在整个卵子发生过程中将发育中的卵母细胞连接到卵泡细胞。它们首先在鲨类（鲨鱼）中被描述，它们的建议作用是促进代谢物向发育中的卵母细胞运输，并为鲨鱼的大卵细胞提供结构支持，这是胎生进化的早期阶段。随后的研究发现在 Rajiformes（冰鞋）中不存在 FCP，这表明 FCP 可能是鲨鱼特有的新结构。在这里，我们描述了嵌合体 Hydrolagus colliei 中的 FCP。H. colliei 的 FCP 在形态上不同于先前在鲨鱼中描述的那些，但由于它们也含有肌动蛋白，它们可能在提供发育中的卵母细胞和提供结构支持方面发挥着相似的作用。FCP 在 Chimaeriformes 目中的存在表明它们的起源早于 Elasmobranchs 和 Holocephalans 的分裂。本文受版权保护。版权所有。