Pinning down the phylogenetic position of Chaetognatha: architecture of their nervous system in comparison to potential outgroups

确定毛颌动物的系统发育位置：与潜在外群相比，其神经系统的结构

• 批准号: 5453109
• 负责人: Professor Dr. Steffen Harzsch
• 金额: --
• 依托单位: Arbeitsgruppe Cytologie und Evolutionsbiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5453109?language=en
• 关键词: Pinning; down; phylogenetic; position; Chaetognatha

We analyse the nervous system of Chaetognatha against an evolutionary background in order to provide new insights into the phylogenetic position of this taxon (Neurophylogeny). In this application, we thoroughly report our work progress during Phase 2 of SPP 1174 „ Deep Metazoan Phylogeny“ including joint activities of all Neurophylogeny groups in the SPP such as establishing a glossary of neuroanatomical terms in invertebrates. The major goal of our application for Phase 3 is to finally pin down the phylogenetic position of Chaetognatha. To that end, we suggest dedicating circa 60% of the Phase 3 work efforts to obtaining additional neuroanatomical data to fill gaps of knowledge that became obvious during Phase 1 and 2. Circa 40% of the Phase 3 work efforts will be directed towards the analysis of the data together with the other neurophylogeny groups in a joint data matrix and a combined analysis of morphological data. More precisely: 1. Because so far we have analyzed only two chaetognath species, we suggest extending the taxon sampling for a broad comparative analysis of brain structure and arrangement of individually identifiable neurons in the ventral nerve centre in order to work out the representative nervous system ground pattern of Chaetognatha as a solid basis for the following phylogenetic analysis with other protostomian taxa and for the correct coding of nervous system characters in the matrix. Furthermore, this approach will contribute characters to resolve chaetognath internal phylogeny. 2. We propose to use the full set of markers that we have already successfully used for the Chaetognatha to study the nervous system of Gnathostomulida, a potential outgroup of Chaetognatha. The aim is to obtain a stable reconstruction of the nervous system in the ground pattern of this taxon. This approach will be vital to fill the existing gaps in the neuronatomical data set for the matrix and will allow for an immediate test of the Gnathifera hypothesis as suggested by Nielsen (2001) in which the Chaetognatha are suggested to be relatives of Gnathostomulida, Rotatoria and other gnathiferan taxa. 3. One of the ultimate goals of the priority program is a combined analysis of all the morphological data compiled by the DMP collaborators, and in a second step the combination of morphological and molecular data. The analysis of the Neurophylogeny team will focus on structures which, primarily, we have studied in person. Other aspects of our innovative approach of data analysis include the development of a strict terminology and the critical conceptualization of characters, including a test of primary homology for these conceptualized characters. We have already development such a terminology by establishing a glossary of neuroanatomical terms for invertebrates in Phase 2. The morphological database of DMP, MorphDBase takes on a central function in the interlocking of the different morphological projects within the priority program and managing and facilitating the generation of a combined morphological character matrix. For establishing the character matrixs we will also interact with participants of the “Protostome Tree of Life” AtoL group.

我们分析了毛颚类的神经系统的进化背景，以提供新的见解，这个分类群的系统发育位置（神经系统发育）。在本申请中，我们全面报告了SPP 1174“深层后生动物系统发育”第2阶段的工作进展，包括SPP中所有神经系统发育组的联合活动，例如建立无脊椎动物神经解剖学术语表。我们申请第三阶段的主要目标是最终确定毛颚类的系统发育位置。为此，我们建议将大约60%的第3阶段工作用于获得额外的神经解剖学数据，以填补在第1阶段和第2阶段中变得明显的知识空白。大约40%的第3阶段工作将用于联合数据矩阵中的数据分析以及其他神经发育组和形态学数据的综合分析。更确切地说：1.因为到目前为止我们只分析了两种毛颚类，我们建议扩大分类群的取样范围，对脑结构和腹神经中枢中可单独识别的神经元的排列进行广泛的比较分析，以确定毛颚类的代表性神经系统基础模式，作为与其他原口类分类群进行系统发育分析的坚实基础，并为毛颚类神经系统特征的正确编码奠定基础。矩阵。此外，这种方法将有助于字符的解决毛颚类内部生殖。2.我们建议使用全套的标记，我们已经成功地用于毛颚类研究的Gnathostomulida，毛颚类的一个潜在的外群的神经系统。目的是获得一个稳定的重建的神经系统在该分类群的基础模式。这种方法将是至关重要的，以填补现有的差距，在神经元数据集的矩阵，并将允许立即测试的Gnathifera的假设所建议的尼尔森（2001年），其中毛颚类被认为是Gnathostomulida，Rotatoria和其他nathiferan类群的亲属。3.该优先计划的最终目标之一是对所有形态学数据进行综合分析，并在第二步中将形态学和分子数据结合起来。神经发育学团队的分析将集中在我们亲自研究的结构上。我们的创新方法的数据分析的其他方面包括一个严格的术语和字符的关键概念化的发展，包括这些概念化字符的主要同源性测试。在第二阶段，我们已经通过建立无脊椎动物的神经解剖学术语表，发展了这样一个术语。MorphDBase的形态数据库在优先级程序中的不同形态项目的互锁以及管理和促进组合形态特征矩阵的生成中起着中心作用。为了建立角色矩阵，我们还将与“生命之树”AtoL小组的参与者进行互动。