Mechanisms of asymmetric cell division during female meiosis

女性减数分裂过程中不对称细胞分裂的机制

• 批准号: 7316169
• 负责人: Francis J McNally
• 金额: $ 30.67万
• 依托单位: UNIVERSITY OF CALIFORNIA AT DAVIS
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-15 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7316169
• 关键词: Anaphase; Aneuploidy; Animals; Binding Proteins; Biochemistry; Biological Assay; Body Size; Caenorhabditis elegans; Cell division; Chondroitin; Chromosome Segregation; Chromosomes; Cloning; Complex; Congenital Abnormality; Cytokinesis; Cytoplasmic Granules; Down Syndrome; Embryo; Failure; Female; Fertilization; Film; Fluorescence Microscopy; Generations; Genetic; Genome; Goals; Green Fluorescent Proteins; Health; Human; Image; In Vitro; Kinesin; Lead; Length; Light; Localized; Mediating; Meiosis; Metaphase; Microtubules; Modeling; Molecular; Monitor; Movement; Pathway interactions; Patients; Positioning Attribute; Proteins; Proteoglycan; Public Health; RNA Interference; Research Personnel; Role; Rotation; Sister Chromatid; Slide; Spontaneous abortion; Stem cells; Testing; Therapeutic; Time; anaphase-promoting complex; animal cloning; cell motility; density; egg; human disease; katanin; killings; mutant; novel; prevent; programs; research study; sperm cell; sperm protein; stem cell therapy; time use; zygote

DESCRIPTION (provided by applicant): Our goal is to understand the mechanisms that position female meiotic spindles at the egg cortex and that mediate polar body formation. In the long term, we hope to elucidate the reasons why asymmetric meiotic spindle positioning is so conserved across animal phyla. The specific goals of this proposal are to elucidate the detailed mechanisms of three distinct pathways that mediate meiotic spindle positioning and polar body formation in Caenorhabitis elegans. 1) Kinesin-1 heavy chain, kinesin light chains and a novel protein called KCA-1 are each required to move the meiotic spindle to the egg cortex before the metaphase-anaphase transition. In contrast, movement of the meiotic spindle to the egg cortex after the metaphase-anaphase transition is kinesin-independent. We will use fluorescence microscopy and in vitro biochemistry to test the hypothesis that a kinesin/KCA-1 complex directly transports the spindle along cytoplasmic microtubules and that a distinct mechanism is responsible for both spindle translocation in the absence of kinesin and spindle rotation during wild-type meiosis. 2) Complete loss of the microtubule-severing protein, katanin, results in failure to assemble a meiotic spindle whereas partial loss of katanin function results in abnormally long meiotic spindles and abnormally large polar bodies. We will use fluorescence microscopy and genetics to test the hypothesis that microtubule-severing activity restricts meiotic spindle length and thereby polar body size. 3) SPE-11 is a sperm protein introduced into the egg at fertilization and which is required for polar body formation. We will use a combination of fluorescence microscopy and genetics to test the hypothesis that SPE-11 mediates polar body formation by interacting with conserved cytokinesis regulators in the egg. Meiotic spindles are relevant to public health for two major reasons. First, abnormal meiotic spindle function leads to aneuploidy that causes Down syndrome and miscarriage. Second, the potential for treating numerous human diseases with patient-matched stem cells is currently limited by abnormal meiotic spindle assembly during animal cloning. A detailed molecular understanding of meiotic spindle function could thus lead to treatments that prevent birth defects and that allow stem cell therapy of human diseases.

描述（由申请人提供）：我们的目标是了解将雌性减数分裂纺锤体定位在卵皮层并介导极体形成的机制。从长远来看，我们希望阐明为什么不对称减数分裂纺锤体位置在动物门中如此保守的原因。该提案的具体目标是阐明介导秀丽隐杆线虫减数分裂纺锤体定位和极体形成的三种不同途径的详细机制。 1) 在中期-后期转变之前，需要驱动蛋白-1 重链、驱动蛋白轻链和一种名为 KCA-1 的新型蛋白质将减数分裂纺锤体移动到卵皮层。相反，减数分裂纺锤体在中期-后期转变后向卵皮层的运动是独立于驱动蛋白的。我们将使用荧光显微镜和体外生物化学来检验以下假设：驱动蛋白/KCA-1 复合物直接沿着细胞质微管运输纺锤体，并且一种独特的机制负责在缺乏驱动蛋白的情况下纺锤体易位和野生环境下纺锤体旋转。型减数分裂。 2）微管切断蛋白剑蛋白的完全丧失导致减数分裂纺锤体组装失败，而剑蛋白功能部分丧失则导致减数分裂纺锤体异常长和极体异常大。我们将使用荧光显微镜和遗传学来检验微管切断活性限制减数分裂纺锤体长度从而限制极体大小的假设。 3) SPE-11 是受精时引入卵子的精子蛋白，是极体形成所必需的。我们将结合使用荧光显微镜和遗传学来检验 SPE-11 通过与卵子中保守的胞质分裂调节因子相互作用来介导极体形成的假设。减数分裂纺锤体与公共卫生相关有两个主要原因。首先，减数分裂纺锤体功能异常会导致非整倍体，从而导致唐氏综合症和流产。其次，目前用与患者匹配的干细胞治疗多种人类疾病的潜力受到动物克隆过程中减数分裂纺锤体组装异常的限制。因此，对减数分裂纺锤体功能的详细分子理解可能会导致预防出生缺陷和允许干细胞治疗人类疾病的治疗方法。