MITOTIC SPINDLES IN NEMATODES: COMPARATIVE BIOPHYSICS TO EVOLUTIONARY BIOLOGY

线虫中的有丝分裂纺锤体：生物物理学与进化生物学的比较

• 批准号: 8362559
• 负责人: THOMAS MUELLER-REICHERT
• 金额: $ 3.19万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8362559
• 关键词: 3-Dimensional; Address; Architecture; Behavior; Biology; Biophysics; Caenorhabditis; Caenorhabditis elegans; Cell Size; Cell physiology; Cells; Cellular Structures; Comparative Study; Dependence; Electron Microscopy; Embryo; Eukaryota; Evolution; Exhibits; Fluorescence; Funding; Genetic; Grant; Karyotype; Lead; Measures; Metaphase; Methods; Microtomy; Microtubules; Mitosis; Mitotic spindle; Modeling; Molecular; Morphology; Mutation; National Center for Research Resources; Nematoda; Organism; Phylogenetic Analysis; Principal Investigator; Quantitative Microscopy; Research; Research Infrastructure; Resources; Shapes; Source; Structure; Techniques; Tissues; United States National Institutes of Health; Variant; Work; base; comparative; cost; insight; life history; light microscopy; mathematical model; research study

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Mitotic spindles can show remarkable variability between tissues and organisms, but there is currently little understanding of the evolutionary basis of this diversity. Thus it is unclear why metaphase spindles in different Eukaryotes exhibit a range of morphologies and the volumes of these spindles vary over one thousand fold. Here, we propose a comparative study to investigate the evolutionary forces that shape the mitotic spindle. We will use one-cell nematode embryos in mitosis to address three broad questions: 1) What is the extent of variation in spindle dynamics and structure? We will investigate both small and large phylogenic distances by studying ~60 species from across the nematode phylum - including all known species of the Caenorhabditis genus. This work will use a number of light microscopy techniques to determine the range of spindle variation in nematodes. 2) What is the biophysical basis of this variation? We will perform an in-depth analysis of microtubule dynamics and spindle architecture in ~10 select species. Fluorescence techniques (when possible in nonmodel species), thin-section and 3-D electron microscopy, and perturbations experiments, both physical and genetic (when feasible), will be used to measure the dynamics, number and behavior of microtubules. We will develop biophysical models to explain how differences in microtubule behavior lead to differences in spindle architecture. 3) What is the evolutionary basis of this variation? We will use models of phenotypic evolution to gain insight into: (i) the extent of phylogenetic effects; (ii) the dependence of spindle features on cell size, karyotype, life history, and other attributes; and (iii) the importance of selection and drift in shaping various components of the spindle. A parallel study on one species, Caenorhabditis elegans, will provide a more detailed analysis of evolutionary forces: we will use mutation accumulation lines to measure how spontaneous mutations modify the mitotic spindle, and we will determine how this variability is shaped over evolution by comparing these lines with ~40 different wild isolates. This unique comparative approach combines molecular methods, quantitative microscopy, and mathematical modeling, to develop a comprehensive model of how the mitotic spindle is shaped through evolution by mutation, selection, drift, and cellular biophysics.

该副本是利用资源的众多研究子项目之一 由NIH/NCRR资助的中心赠款提供。对该子弹的主要支持 而且，副投影的主要研究员可能是其他来源提供的 包括其他NIH来源。 列出的总费用可能 代表subproject使用的中心基础架构的估计量， NCRR赠款不直接向子弹或副本人员提供的直接资金。 有丝分裂纺锤可以显示组织和生物之间的显着变异性，但是有 目前对这种多样性的进化基础很少了解。因此，目前尚不清楚为什么不同真核生物中的中期纺锤体表现出一系列形态和这些纺锤体的体积在一千倍上有所不同。在这里，我们提出了一项比较研究，以研究塑造有丝分裂纺锤体的进化力。我们将在有丝分裂中使用一细胞线虫胚胎来解决三个广泛的问题： 1）主轴动力学和结构的变化程度是多少？我们将通过研究来自线虫门的大约60种物种（包括Caenorhabditis属的所有已知物种），研究小小的系统发育距离。这项工作将使用许多光学显微镜技术来确定线虫中主轴变化的范围。 2）这种变异的生物物理基础是什么？我们将对〜10个精选物种中的微管动力学和主轴结构进行深入分析。荧光技术（如果在非模型物种中），薄片和3-D电子显微镜以及物理和遗传的扰动实验（可行的情况下）将用于测量微管的动力学，数量和行为。我们将开发生物物理模型，以解释微管行为的差异如何导致纺锤体结构的差异。 3）这种变化的进化基础是什么？我们将使用表型进化的模型来深入了解：（i）系统发育效应的程度； （ii）主轴特征对细胞大小，核型，生活史和其他属性的依赖性； （iii）选择和漂移在塑造主轴的各个组件中的重要性。一项对一种物种Caenorhabditis秀丽隐杆线虫的平行研究将提供对进化力的更详细的分析：我们将使用突变积累线来测量自发突变如何改变有丝分裂的纺锤体，我们将通过将这些变异性与〜40不同的野生分离株进行比较来确定这种变异性如何通过比较这些线来塑造进化。这种独特的比较方法结合了分子方法，定量显微镜和数学建模，以开发一个综合模型，说明如何通过突变，选择，漂移和细胞生物物理学通过进化来形成有丝分裂的纺锤体。