Molecular Evolution and Deep Phylogeny of Deuterostomia

寒武纪后口动物的辐射导致了棘皮动物门、半索动物门和脊索动物门三大谱系的形成。这些亚群之间和内部的系统发育关系一直是一个长期和有争议的辩论。到目前为止，应用的分子方法并没有对这个问题做出重大贡献。这在我们对后生动物关系的理解以及基本形态特征（如背索和带鳃裂的肠道）的进化方面留下了很深的空白。在特殊的研究计划深后生动物系统发育，我们的目标是有助于重建的系统发育关系的主要后口类谱系使用的序列和基因顺序的进化组蛋白基因簇作为分子工具。总体而言，大多数数据缺乏半索动物。因此，我们将主要关注这一组，通过仍然缺失的小和大核糖体RNA序列来扩展组蛋白数据集。此外，将分离Espressed序列标签，用于将来分析其他遗传信息基因。

The radiation of Deuterostomia in the Cambrian resulted in three major lineages, the Echinodermata, Hemichordata, and Chordata. The phylogenetic relationships between and within these subgroups have been a matter of long and controversial debate. The molecular approach applied until now did not contribute significantly to the problem. This leaves a deep gap in our understanding of metazoan relationships as well as in the evolution of fundamental morphological characters such as the chorda dorsalis and the gut with gill slits. Within the special research programme Deep Metazoan Phylogeny we aim to contribute to the reconstruction of phylogenetic relationships of the major deuterostome lineages using the sequence and gene order evolution of the histone gene cluster as a molecular tool. Overall, most data are lacking in hemichordates. Thus, we will mainly focus on this group, extending the histone data set by still missing small and large ribosomal RNA sequences. Furthermore, Espressed Sequence Tags will be isolated for future analyses of additional phylogenetically informative genes.