ATOL: Phylum Nematoda: Integrating Multidisciplinary Expertise and Infrastructure for Resolving Relationships in a Major Branch of the Tree of Life

新罕布什尔大学的 William K Thomas 博士及其同事 James Baldwin 博士和 Paul De Ley 博士（加州大学河滨分校）、David Fitch 博士（纽约大学）和 Steven Nadler 博士（加州大学戴维斯分校）获得了一笔资助，以研究线虫的进化历史和生物多样性。 线虫门（蛔虫）被认为是地球上数量最丰富、遗传多样性最丰富的动物门之一。 此外，它们在动物进化和理解有争议的无脊椎动物进化关系中发挥着关键作用。对如此庞大的门的系统发育研究因难以处理如此多样化的类群而受到阻碍，其中大多数类群都是微观的，并且只有相对较少的专家知道。不同学科分类专家的分散以及对经济或医学上重要的植物、脊椎动物和无脊椎动物寄生虫的偏见也阻碍了线虫系统发育。 因此，了解它们的进化历史是美国国家科学基金会组装生命之树计划的一个关键组成部分。 该项目将为线虫开发一个更高级别的树，以提供解释其多样性的框架。 这项工作将使用 1000 多个物种的分子（18S 核糖体基因）和形态学数据。 与此同时，他们将利用这项工作的结果作为选择 50 种线虫物种用于构建 cDNA 文库的基础，以更深入地了解该门的遗传多样性，并可能解决有关线虫树最深分支甚至其在动物界中的系统发育位置的长期存在的问题。

A grant has been awarded to Dr. William K Thomas at the University of New Hampshire and his colleagues Dr. James Baldwin and Dr. Paul De Ley (University of California, Riverside), Dr. David Fitch (New York University) and Dr. Steven Nadler (University of California, Davis) to examine the evolutionary history and biodiversity of nematodes. The phylum Nematoda (roundworms) is argued to be one of the most abundant and genetically diverse animal phyla on earth. In addition, they play a key position in animal evolution and understanding of controversial invertebrate evolutionary relationships. Phylogenetic studies of this enormous phylum have been impeded by the difficulty of working with such diverse taxa, most of which are microscopic and known by relatively few experts. Nematode phylogenetics has also been impeded by the fragmentation of taxonomic specialists among different disciplines and by bias toward economically or medically important parasites of plants, vertebrates and invertebrates. Accordingly, understanding their evolutionary history is a critical component in the NSF's Assembling the Tree of Life program. This project will develop a higher-level tree for the nematodes to provide a framework for interpreting their diversity. The work will use both molecular (18S ribosomal genes) and morphological data for over 1000 species. In a parallel effort, they will use the results of this work as a basis for selecting 50 nematode species for construction of cDNA libraries to provide greater insight into genetic diversity in the phylum and to possibly resolve the longstanding questions about of the deepest branches of the nematode tree or even its phylogenetic position in the animal kingdom.