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

基本信息

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
项目类别：
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

项目摘要

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女性减数分裂纺锤体定位在卵皮层中的机制，并介导极体形成。从长远来看，我们希望阐明为什么在动物门中如此保守的不对称减数分裂纺锤体定位的原因。该提案的具体目标是阐明三种不同的途径的详细机制，这些途径介导了秀丽隐杆线虫中的减数分裂纺锤体定位和极性身体形成。 1）动力蛋白-1重链，运动蛋白光链和一种称为KCA-1的新型蛋白质是在中期 - 分析酶转变之前将减数分裂纺锤体移至鸡蛋皮层所必需的。相比之下，中期 - 动力学转变后，减数分裂纺锤体向卵皮层的运动是无关的。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复合物直接沿细胞质微管直接运输纺锤体，并且在野生型中缺乏运动蛋白和脊柱旋转的情况下，具有独特的机制是纺锤体易位的原因。 2）完全丧失了微管 - 细胞的蛋白Katanin，导致无法组装减数分裂的纺锤体，而Katanin功能的部分损失导致异常长的减数分裂纺锤体和异常大的极性。我们将使用荧光显微镜和遗传学来检验以下假设：微管 - 细胞延迟活性限制了减数分裂的长度，从而限制了极性体型。 3）SPE-11是一种在受精时引入鸡蛋的精子蛋白，是极性体形成所必需的。我们将使用荧光显微镜和遗传学的组合来测试SPE-11通过与卵中保守的细胞因子调节剂相互作用来介导极体形成的假设。减数分裂纺锤与公共卫生有关，有两个主要原因。首先，异常的减数分裂纺锤体功能导致非整倍性引起唐氏综合症和流产。其次，目前，用患者匹配的干细胞治疗众多人类疾病的潜力受动物克隆期间的减数分裂纺锤体组件的限制。因此，对减数分裂纺锤功能的详细分子理解可能导致预防先天缺陷并允许干细胞治疗人类疾病的治疗。