Cleavage patterns and gastrulation as complex characters for phylogenetic inferences in the Metazoa: the early development of Rotifera (II) and Kinorhyncha

早期个体发育阶段的分析有助于解决后生动物的系统发育关系。这里我们要解决两个问题。一个是Rotifera是否像Lophotrochozoa/Spiralia假说所建议的那样显示出螺旋分裂或其痕迹，或者它们是否显示出与Cycloneuralia更相关的分裂类型。第二个问题涉及Kinorhyncha的早期发育及其对原始外生动物卵裂模式重建的贡献。我们对这两个群体的卵裂模式和原肠胚形成的了解仍然是零碎的。为了填补这些空白，我们希望通过从组织学到4d显微镜的各种方法，详细研究Rotifera和Kinorhyncha代表植物的早期卵裂模式、细胞系、细胞命运和原肠胚形成模式。我们的结果将与文献中的现有数据进行比较。与“深层后生动物系统发育”网络合作，发育特征将被定义，概念化，输入到一个全面的形态数据矩阵中，并最终用于分析后生动物系统发育。

The analysis of early ontogenetic stages can contribute to the resolution of metazoan phylogenetic relationships. Here we address two questions. One is whether the Rotifera show spiral cleavage or traces thereof as is suggested by the Lophotrochozoa/Spiralia hypothesis or whether they show a cleavage type which is more related to that of Cycloneuralia. The second question deals with the early development of Kinorhyncha and its contribution to the reconstruction of the ancestral ecdysozoan cleavage pattern. Our knowledge about the cleavage pattern and the gastrulation of both groups is still fragmentary. To fill these gaps we want to study the early cleavage patterns, the cell lineages, the cell fates, and the gastrulation modes of representatives of Rotifera and Kinorhyncha in great detail with a variety of methods ranging from histology to 4D-microscopy. Our results will be compared with available data from the literature. In collaboration with the “Deep Metazoan Phylogeny” network, the developmental characters will be defined, conceptualised, fed into a comprehensive morphological data matrix, and eventually used to analyse metazoan phylogenetics.