Nervous system development in sea spiders (Arthropoda, Pycnogonida): combining morphology and gene expression to reconstruct the euarthropod ground pattern

海蜘蛛（节肢动物，Pycnogonida）的神经系统发育：结合形态学和基因表达来重建真节肢动物的地面模式

• 批准号: 85623853
• 负责人: Professor Dr. Gerhard Scholtz
• 金额: --
• 依托单位: Arbeitsgruppe Vergleichende Zoologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2008
• 资助国家: 德国
• 起止时间: 2007-12-31 至 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/85623853?language=en
• 关键词: Nervous; system; development; sea; spiders

Comparative studies of neurogenesis provide valuable clues for phylogenetic relationships and ner-vous system evolution of euarthropods. Representatives of hexapods, crustaceans, myriapods, and chelicerates have been studied with respect to (1) the formation of stem-cell like neural progenitor cells (neuroblasts) or small clusters of immigrating neuronal cells, (2) a stereotyped arrangement of the respective neural precursors within each hemisegment, (3) an association between ectodermal cell proliferation and immigration, and (4) the genetic 2 network underlying these processes. Moreover, data on early axonogenesis provide insights into the establishment and spatial arrangement of the axonal scaffold in central nervous system. However, missing studies in some euarthropod taxa and outgroups such as Onychophora and Tardigrada render the reconstruction of ancestral neurogenesis and thus the polarity of neurogenic evolutionary transformations of euarthropods difficult. Owing to their basal position either in chelicerates or euarthropods in general, sea spiders (Pycnogonida) are critical for this analysis. However, despite some recent progress most aspects of pycnogonid neuro-genesis are still controversial and insufficiently known. To diminish this lack of knowledge, neural precursor formation and axonogenesis of pycnogonids will be studied in detail, combining different morphological approaches and gene expression analyses. It will be tested whether early neurogenesis in sea spiders shows more similarities to euchelicerates and myriapods or to onychophorans. Obtai-ned data will contribute to the reconstruction of evolutionary changes in euarthropod neurogenesis.

神经发生的比较研究为真节肢动物的系统发育关系和神经系统进化提供了有价值的线索。六足类、甲壳类、多足类和海龟的代表性研究涉及(1)干细胞样神经前体细胞(神经母细胞)或迁移神经细胞的小簇的形成，(2)每个半节段内各自神经前体的刻板排列，(3)外胚层细胞增殖和迁移之间的联系，以及(4)这些过程背后的遗传网络。此外，早期轴突发生的数据为中枢神经系统轴突支架的建立和空间排列提供了洞察力。然而，在一些真节肢动物类群和外类群中缺失的研究使得重建祖先的神经发生变得困难，从而导致真节肢动物神经性进化转化的两极分化。由于它们在海龟或真节肢动物中的基本位置，海蜘蛛(海蜘蛛纲)对本分析至关重要。然而，尽管最近取得了一些进展，但对于碧玉神经发生的大部分方面仍然存在争议，而且了解得还不够充分。为了减少这种知识的缺乏，将结合不同的形态学方法和基因表达分析，详细研究碧龙鱼的神经前体形成和轴突发生。将测试海蜘蛛的早期神经发生是否显示出与真螺旋虫和多足动物更相似的地方，还是与指甲虫更相似的地方。观察数据将有助于重建真节肢动物神经发生的进化变化。