IDENTIFICATION OF DEVELOPMENTAL MODULES IN CEPHALOBID NEMATODES

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 头形线虫科（英语：Cephalobidae）（线虫纲：小杆线虫纲）是一种非寄生性的微生物摄食线虫，具有称为probolae的头部表皮附属物。它们几乎无处不在地分布在陆地生态系统中，但对它们的生物学知之甚少。 Probolae是最重要的特征，用于分类的目的，在组中，他们的多样性和复杂性，使他们有趣的模型进化问题。它们是细胞外基质的复杂延伸，这进一步增加了了解其形态和形态发生的重要性。2001年在NCMIR进行的部分初步工作表明，电子断层扫描将被证明对描述其复杂的3D结构是非常宝贵的，包括组成probolae的多达7种不同蛋白质层压体之间的关系。这里提出的工作将有助于一个更大的项目，其目的是制定和测试假设的发展模块，可用于回答一般问题的起源小说人物和发展的演变。它将与系统发育，发育和SEM信息相结合，以解决理论进化问题，并提供一个非常需要的解剖学描述，以解决有关系统发育分析和诊断目的中使用的字符的同源性问题。除了帮助实现这些研究目标，断层重建将包含其他感官和喂养结构的显着利益的发育遗传学家和进化生物学家使用线虫模型的信息，这项工作将有助于评估技术更广泛的应用在了解线虫解剖。加州大学滨江分校的CM 300中压显微镜已经可以使用，它将用于预览材料和对电子束预曝光切片。初步工作表明，对比度是获得表皮结构图像的限制因素，因此将使用NCMR的新能量过滤显微镜获取最终的断层扫描系列。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Members of the family Cephalobidae (Nematoda: Rhabditida) are non-parasitic microbial-feeding nematodes with cephalic cuticular appendages called probolae. They are nearly ubiquitously distributed in terrestrial ecosystems, yet very little is known of their biology. Probolae are the most important characters used for taxonomic purposes in the group, and their diversity and complexity makes them interesting models for evolutionary questions. They are complex extensions of the extracellular matrix, which adds further importance to understanding their morphology and morphogenesis. Preliminary work done in part at the NCMIR in 2001 suggests that electron tomography would prove invaluable for describing their complex 3D structure, including the relationship between up to seven different protein laminates of which probolae are composed. The work proposed here would contribute to a larger project which aims to formulate and test hypotheses of developmental modules that could be utilized to answer general questions about the origin of novel characters and the evolution of development. It will be combined with phylogenetic, developmental and SEM information in order to address theoretical evolutionary questions and provide a much needed description of anatomy in order to address issues concerning the homology of characters used in phylogenetic analyses and for diagnostic purposes. In addition to helping accomplish these research goals, the tomographic reconstruction will contain information on other sensory and feeding structures of significant interest to developmental geneticists and evolutionary biologists who use nematode models, and the work will serve to evaluate the technique for much broader application in understanding nematode anatomy. Access to a CM300 mid voltage microscope at the University of California, Riverside is already available, which would be used to preview material and to pre-expose sections to the electron beam. Preliminary work showed that contrast was the limiting factor for obtaining images of cuticular structures, so the new energy filtered microscope at the NCMIR would be used for acquiring the final tomographic series.