PDF(Pubmed)
Abstract：
The formation of extraembryonic membranes (EEMs) contributes to the proper development of many animals. In arthropods, the formation and function of EEMs have been studied best in insects. Regarding the development of extraembryonic tissue in chelicerates (spiders and relatives), most information is available for spiders (Araneae). Especially two populations of cells have been considered to represent EEMs in spiders. The first of these potential EEMs develops shortly after egg deposition, opposite to a radially symmetrical germ disc that forms in one hemisphere of the egg and encloses the yolk. The second tissue, which has been described as being extraembryonic is the so-called dorsal field, which is required to cover the dorsal part of the developing spider germ rudiment before proper dorsal closure. In this review, we summarize the current knowledge regarding the formation of potential extraembryonic structures in the Chelicerata. We describe the early embryogenesis of spiders and other chelicerates, with a special focus on the formation of the potential extraembryonic tissues. This article is part of the theme issue \'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom\'.
摘要：
胚胎外膜（EEM）的形成有助于许多动物的正常发育。在节肢动物中，EEM的形成和功能在昆虫中得到了最好的研究。关于螯合物（蜘蛛和亲戚）中胚胎外组织的发育，大多数信息可用于蜘蛛（Araneae）。特别是两个细胞群被认为代表蜘蛛中的EEM。这些潜在的EEM中的第一个在卵沉积后不久发展，与径向对称的胚盘相对，胚盘形成在蛋的一个半球并包围蛋黄。第二个组织，被描述为胚胎外的是所谓的背场，在适当的背侧闭合之前，需要覆盖发育中的蜘蛛胚芽雏形的背侧。在这次审查中,我们总结了当前有关Chelicerata中潜在胚外结构形成的知识。我们描述了蜘蛛和其他螯合物的早期胚胎发生，特别关注潜在胚外组织的形成。这篇文章是主题问题的一部分\'胚胎外组织：探索概念，动物王国的定义和功能。
