The analysis of body axis formation in the common house spider Parasteatoda tepidariorum

普通家蜘蛛Parasteatoda tepidariorum体轴形成分析

基本信息

批准号：
226588632
负责人：
Dr. Matthias Pechmann
金额：
--
依托单位：
Institut für Entwicklungsbiologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2012
资助国家：
德国
起止时间：
2011-12-31 至 2017-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/226588632?language=en
关键词：
analysis body axis formation common

项目摘要

Setting up the dorsoventral and the anteroposterior body axes is a fundamental process during the embryonic development of all bilaterian animals. In spider embryos, a cellular structure called the cumulus is the main organizer of the embryonic axes. While other arthropods do not have such a structure, the cumulus is remarkably similar to the organizer that specifies the axes of amphibian embryos (Spemann organizer). Both organizers function via BMP signalling, and are able to induce a secondary body axis in the respective embryos. The function of the cumulus has been best studied in the common-house spider Parasteatoda tepidariorum. It is known that the cumulus acts as a source of BMP signalling required to specify the dorsoventral body axis of the spider embryo. The cumulus arises in the center of the radially-symmetric germ-disc and migrates to its periphery. Through this migration the cumulus breaks the radial symmetry of the germ-disc. However, the molecular basis of germ-disc formation, cumulus specification and dpp activation in the cells of the cumulus are completely unknown. In the initial research proposal, I analysed germ-disc formation via embryonic injection of cytoskeleton and RNA polymerase inhibitors, and via parental RNA interference with candidate genes of the Toll- and the EGF-signalling pathways as well as many other candidate transcription factors. While I could show that germ-disc formation requires the actin (but not the tubulin) cytoskeleton and zygotic transcription, the candidate gene approach did not result in germ-disc or axial patterning phenotypes. Therefore, the new approach of the renewal proposal is based on genes that have been selected from new transcriptome data. A pilot RNAi screen with ten new candidate genes already resulted in two striking dorsoventral patterning phenotypes and one gap-gene like phenotype. These results demonstrate that the selection of the new candidate genes is accurate, and that this is an excellent approach for identifying the genes most important for spider axis determination. The dorsoventral phenotypes are especially interesting, as one of the genes is a completely novel regulator of cumulus migration, and the other gene may be upstream of BMP signalling (something that has never been described before). Given these exciting preliminary results, a functional screen of the remaining genes from the transcriptome data will likely yield many more interesting and novel phenotypes.

在所有双尾动物的胚胎发育过程中，建立背腹和前后体轴是一个基本过程。在蜘蛛胚胎中，称为库卢斯的细胞结构是胚胎轴的主要组织者。尽管其他节肢动物没有这种结构，但积云与指定两栖动物胚胎（Spemann组织者）轴的组织者非常相似。两个组织者都通过BMP信号传导功能，并能够在相应的胚胎中诱导次级体轴。在普通蜘蛛parasteatoda tepidariorum中最好地研究了积云的功能。众所周知，积云充当指定蜘蛛胚胎背腹体轴所需的BMP信号来源。积云出现在径向对称的细菌盘的中心，并迁移到其外围。通过这种迁移，积云打破了细菌盘的径向对称性。然而，库卢斯细胞中生殖盘形成，积云规范和DPP激活的分子基础是完全未知的。在最初的研究建议中，我通过胚胎注射细胞骨架和RNA聚合酶抑制剂分析了细菌盘形成，并通过父母RNA干扰Toll-和EGF-信号途径的候选基因以及许多其他候选转录因子。虽然我可以证明菌盘形成需要肌动蛋白（而是微管蛋白）的细胞骨架和二细转录，但候选基因方法并未导致胚芽或轴向图案表型。因此，续订建议的新方法基于已从新的转录组数据中选择的基因。具有十个新候选基因的Pilot RNAi屏幕已经导致了两种醒目的背腹图型表型和一种像表型这样的间隙基因。这些结果表明，新候选基因的选择是准确的，这是确定对蜘蛛轴确定最重要的基因的绝佳方法。背腹表型特别有趣，因为其中一个基因是云迁移的完全新颖的调节剂，而另一个基因可能是BMP信号传导的上游（以前从未描述过）。鉴于这些令人兴奋的初步结果，从转录组数据中对剩余基因的功能屏幕可能会产生更多有趣和新颖的表型。