Genomic Approaches to Metazoan Evolution: Lophotrochozoans and Hox Genes

本计画将研究Hox基因，它指定了身体计划的基本组织，以重建Lophotrochozoans的进化关系。 作为双侧动物的三大谱系之一，这一组包含了最大的身体平面组织的多样性，据称至少有10个公认的门（包括环节动物，软体动物，外肛动物，腕足动物和扁形动物）。 在形成后生动物宏观进化和多样化的因素被理解之前，lophotrochozoans的进化关系是至关重要的。 除了构建基因谱系外，这项工作还将利用Hox簇的组织和基因组成信息。 为此，将产生四个细菌人工染色体文库，从而允许对整个Hox簇进行测序。 为了扩大这个文库，进化历史将重建从28S rDNA和COI基因的49 lophotrochozoa类群。 这项研究将提供可用于解决几个长期存在的问题的数据，包括了解分割和胚胎发生的进化和发育可塑性。

This project will examine the Hox genes, which specify the fundamental organization of body plans, to reconstruct the evolutionary relationships of lophotrochozoans. As one of the three major lineages of bilateral animals, this group contains the greatest diversity of body plan organization and are purported to encompas at least 10 recognized phyla (including annelids, mollusks, ectoprocts, brachipods, and platyhelminthes). Before the factors that shaped metazoan macroevolution and diversification are understood, the evolutionary relationships of the lophotrochozoans are critically needed. In addition to constructing gene geneologies, this work will employ information on organization and gene composition of the Hox cluster. To this end, four bacterial artifical chromosome libraries will be produced, thus allowing the entire Hox cluster to be sequenced. To augment this library, evolutionary history will be reconstructed from 28S rDNA and COI genes for 49 lophotrochozoan taxa. This study will provide data that can be used to address several long-standing issues, including understanding the evolutionary and developmental plasticity of segmentation and embryogenesis.