Institute for Zoology, Department for Developmental Biology, Biocenter, University of Cologne, Zuelpicher Str. 47b, 50674, Cologne, Germany.
Dev Genes Evol. 2020 Mar;230(2):75-94. doi: 10.1007/s00427-020-00653-w. Epub 2020 Feb 19.
Tarantulas represent some of the heaviest and most famous spiders. However, there is little information about the embryonic development of these spiders or their relatives (infraorder Mygalomorphae) and time-lapse recording of the embryonic development is entirely missing. I here describe the complete development of the Brazilian white knee tarantula, Acanthoscurria geniculata, in fixed and live embryos. The establishment of the blastoderm, the formation, migration and signalling of the cumulus and the shape changes that occur in the segment addition zone are analysed in detail. In addition, I show that there might be differences in the contraction process of early embryos of different theraphosid spider species. A new embryonic reference transcriptome was generated for this study and was used to clone and analyse the expression of several important developmental genes. Finally, I show that embryos of A. geniculata are amenable to tissue transplantation and bead insertion experiments. Using these functional approaches, I induced axis duplication in embryos via cumulus transplantation and ectopic activation of BMP signalling. Overall, the mygalomorph spider A. geniculata is a useful laboratory system to analyse evolutionary developmental questions, and the availability of such a system will help understanding conserved and divergent aspects of spider/chelicerate development.
狼蛛是一些最重和最著名的蜘蛛。然而，关于这些蜘蛛或它们的近亲（亚目 Mygalomorphae）的胚胎发育的信息很少，并且完全缺少胚胎发育的延时记录。我在这里描述了巴西白膝狼蛛 Acanthoscurria geniculata 在固定和活体胚胎中的完整发育过程。详细分析了囊胚的建立、卵丘的形成、迁移和信号转导以及在体节附加区发生的形状变化。此外，我还表明，不同的 theraphosid 蜘蛛物种的早期胚胎在收缩过程中可能存在差异。本研究建立了一个新的胚胎参考转录组，并用于克隆和分析几个重要发育基因的表达。最后，我表明 A. geniculata 的胚胎适合进行组织移植和珠子插入实验。使用这些功能方法，我通过卵丘移植和 BMP 信号的异位激活在胚胎中诱导了轴的复制。总的来说，狼蛛 A. geniculata 是一个有用的实验室系统，可以分析进化发育问题，并且这种系统的可用性将有助于理解蜘蛛/螯肢动物发育的保守和分歧方面。
