Evaluation of the Ecdysozoa versus Articulata hypothesis on the basis of complete mitochondrial genome data

计划项目在头两年期间的设想目标是评估外生动物与关节动物的假设，从而确定节肢动物在原口动物中最可能的位置。由于分子数据的不断增加，节肢动物的起源问题再次引起争议。传统上，大多数形态学数据被认为是支持节肢动物和环节动物之间姐妹类群关系的论据，支持关节动物假说。另一方面，分子数据表明节肢动物是部分线虫纲（cyclooneuralia）的姐妹分类群（支持Ecdysozoa分类群），并将环节动物与软体动物和触手动物、部分板类动物和一些较小的类群统一为Lophotrochozoa。在计划中的项目中，将确定线粒体基因组的总序列，特别是Nemathelminthes的线粒体基因组序列，并在系统发育上与节肢动物、软体动物、环节动物和触手动物的线粒体基因组序列进行比较，这些线粒体基因组序列要么已经在数据库中可用，要么仍有待我们或合作研究人员确定。此外，有了这些新数据，特别是Nemathelminthes的数据，人们期望节肢动物系统发育数据分析的结果之一能更详细地描绘出系统发育关系。

The envisaged goal of the planned project within the first two years period is the evaluation of the Ecdysozoa versus the Articulata hypotheses and thus to determine the most likely position of the Arthropoda within the Protostomia. Caused by an increasing amount of molecular data, the origin of the Arthropoda is controversely discussed once again. Traditionally most morphological data are viewed as arguments for a sister group relationship between Annelida and Arthropoda favoring the Articulata hypothesis. On the other hand, molecular data place the arthropods rather as the sister taxon to part of the Nemathelmithes (Cycloneuralia) (supporting the taxon Ecdysozoa) and unify annelids together with the molluscs and tentaculates, part of the Plathelminthes and some minor groups to the Lophotrochozoa. Within the planned project total mitochondrial genome sequences -especially of Nemathelminthes- will be determined and phylogenetically compared to mitochondrial genome sequences of Arthropoda, Mollusca, Annelida and Tentaculata either already available in the database or still to be determined by us or cooperating researchers. Furthermore, with the new data, especially those of Nemathelminthes, a much more detailed picture of phylogenetic relationships within the Arthropoda is expected as one of the results of phylogenetic data analyses.