Mitotic Spindle Assembly & Function in C. elegans

有丝分裂纺锤体组装

• 批准号: 9544967
• 负责人: BRUCE A BOWERMAN
• 金额: $ 48.3万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9544967
• 关键词: ASPM gene; Age; Aneuploidy; Animals; Biological Models; Caenorhabditis elegans; Catalogs; Cell division; Cells; Cellular biology; Centrioles; Centrosome; Chromosome Segregation; Chromosomes; Collection; Cytoplasm; Data; Defect; Development; Down Syndrome; Drosophila genus; Embryo; Family member; Fertility; Fertilization; Foundations; Genes; Genetic; Genetic study; Genome; Haploidy; Human; Investigation; Journals; Kinesin; Kinetochores; Light; Malignant Neoplasms; Manuscripts; Meiosis; Microtubule-Organizing Center; Microtubules; Mitosis; Mitotic; Mitotic spindle; Molecular; Molecular Biology; Mus; Mutation; Nematoda; Oocytes; Pathway interactions; Phenotype; Process; Publishing; RNA Interference; Rana; Reproduction; Role; Structure; Temperature; Time; Video Microscopy; Work; egg; fly; genome editing; improved; literature survey; live cell imaging; mutant; temperature sensitive mutant

Project Summary Oocyte meiosis ends with two rounds of cell division that produce an egg with a haploid genome. While mitosis uses bipolar spindles that assemble using two centrosomes, oocytes assemble bipolar spindles in the absence of centrosomes. While the assembly and function of mitotic spindles have been studied extensively, acentrosomal oocyte spindle assembly remains poorly understood, and C. elegans provides an appealing model system for investigating the mechanisms that govern this process. Moreover, our understanding of oocyte spindle assembly remains incomplete in all widely used model systems, with live cell imaging only recently beginning to shed light on the dynamics of spindle assembly, and somewhat piecemeal genetic studies having provided a partial but incomplete catalogue of the important players. We propose a systematic and quantitative analysis of oocyte meiotic spindle assembly and spindle bipolarity, using a valuable collection of temperature-sensitive mutants we have isolated. We also will use RNA interference to identify the genes and pathways that operate during oocyte spindle assembly in C. elegans, along with live-cell fluorescent video-microscopy and genome editing to provide a more complete and mechanistic understanding of this fundamentally important process. In 2014, we published a manuscript describing our initial work on oocyte spindle pole assembly in Molecular Biology of the Cell, and in 2015 another manuscript in The Journal of Cell Biology and describing our evidence that the microtubule depolymerase KLP- 7/MCAK acts through kinetochores to promote the coalescence of oocyte spindle poles. These results, together with our identification of additional temperature-sensitive mutants with oocyte spindle defects and a thorough survey of the literature covering the most widely used model systems, provide the foundation for the specific aims we now propose to advance our understanding of acentrosomal oocyte meiotic spindle assembly. Even though mitotic spindles rely extensively on centrosomes to organize bipolar spindles, oocyte meiosis and somatic mitosis share the use of acentrosomal pathways for nucleating and organizing microtubules. Thus investigating oocyte spindle assembly will improve our understanding the abnormal mitotic proliferations that result in cancer. Moreover, human oocytes are remarkably prone to errors in spindle assembly and often produce aneuploid oocytes that upon fertilization develop abnormally. A better understanding of oocyte meiotic spindle assembly is therefore relevant to human fertility and development.

项目概要 卵母细胞减数分裂以两轮细胞分裂结束，产生具有单倍体的卵子 基因组。虽然有丝分裂使用双极纺锤体，通过两个中心体组装，但卵母细胞 在没有中心体的情况下组装双极纺锤体。虽然组装和功能 有丝分裂纺锤体已被广泛研究，卵母细胞心体纺锤体组装仍然存在 知之甚少，而秀丽隐杆线虫提供了一个有吸引力的模型系统来研究 控制这一过程的机制。此外，我们对卵母细胞纺锤体组装的理解 在所有广泛使用的模型系统中仍然不完整，活细胞成像直到最近才出现 开始揭示纺锤体组装的动力学，以及一些零碎的遗传 研究提供了重要参与者的部分但不完整的目录。我们 提出对卵母细胞减数分裂纺锤体组装和纺锤体进行系统定量分析 双极性，使用我们分离出的一系列有价值的温度敏感突变体。我们 还将利用 RNA 干扰来识别在卵母细胞发育过程中起作用的基因和途径 线虫纺锤体组装，以及活细胞荧光视频显微镜和基因组 编辑以从根本上提供更完整和机械的理解 重要过程。 2014 年，我们发表了一篇手稿，描述了我们在卵母细胞方面的初步工作 细胞分子生物学中的纺锤体极组装，以及 2015 年《细胞》中的另一篇手稿 细胞生物学杂志并描述了我们的证据，即微管解聚酶 KLP- 7/MCAK 通过着丝粒发挥作用，促进卵母细胞纺锤体极的合并。这些 结果，以及我们对卵母细胞的其他温度敏感突变体的鉴定 主轴缺陷和对涵盖最广泛使用模型的文献的全面调查 系统，为我们现在提出的具体目标提供基础，以推进我们的 了解中心体卵母细胞减数分裂纺锤体组装。 尽管有丝分裂纺锤体广泛依赖中心体来组织双极纺锤体， 卵母细胞减数分裂和体细胞有丝分裂共享着中心体途径来成核和 组织微管。因此，研究卵母细胞纺锤体组装将提高我们的 了解导致癌症的异常有丝分裂增殖。而且，人类 卵母细胞在纺锤体组装中非常容易出现错误，并且经常产生非整倍体 受精后发育异常的卵母细胞。更好地了解卵母细胞减数分裂 因此，纺锤体组装与人类的生育和发育有关。