Mechanisms of chromosome motility during mammalian meiosis

哺乳动物减数分裂过程中染色体运动的机制

• 批准号: 10442797
• 负责人: Jayakrishnan Nandakumar
• 金额: $ 47.97万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2027-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10442797
• 关键词: Adopted; Applications Grants; Architecture; Back; Binding; Biochemical; Biological Models; Biology; Birth; Cell Nucleus; Cell division; Cells; Chromosome Segregation; Chromosomes; Complement; Complex; Congenital Disorders; Cytoskeleton; Cytosol; DNA; Data; Diagnosis; Dissection; Dynein ATPase; Ensure; Event; Fertility; Fertility Disorders; Genes; Genetic; Genetic Recombination; Germ Cells; Haploidy; Higher Order Chromatin Structure; Homologous Gene; Human; In Vitro; Infertility; Investigation; Joints; Knowledge; Lead; Link; Mammals; Meiosis; Meiotic Prophase I; Membrane; Membrane Proteins; Microscopy; Microtubules; Molecular; Motion; Mus; Mutation; Nuclear; Nuclear Envelope; Nuclear Outer Membrane; Organ; Ovum; Positioning Attribute; Preparation; Process; Production; Protein Biochemistry; Proteins; Qualifying; Reproduction; Reproductive Biology; Risk Factors; Sexual Reproduction; Side; Specificity; Spermatocytes; Spontaneous abortion; Structure; Testis; Total Internal Reflection Fluorescent; Ursidae Family; biophysical techniques; cell motility; cell type; daughter cell; improved; in vitro Assay; in vivo; infertility treatment; insight; interdisciplinary approach; live cell microscopy; molecular modeling; prevent; protein protein interaction; protein reconstitution; reconstitution; recruit; segregation; single molecule; sperm cell; telomere

Mechanisms of chromosome motility during mammalian meiosis Project Summary/Abstract Meiosis is a specialized form of cell division of the germline that produces haploid gametes essential for sexual reproduction. A critical step in meiosis is the recombination between homologous chromosomes, also called meiotic crossover, required for the proper segregation of chromosomes into the daughter cells. Imperfect segregation prevents progression through meiosis and is a risk factor for infertility and miscarriage. A detailed understanding of meiotic crossover will enhance the knowledge of meiosis and hold implications for human reproductive biology. Essential to meiotic crossover is a remodeling process in the cell that involves connecting chromosomes in the nucleus to dynein in the cytosol via protein-protein interactions spanning the nuclear envelope. This event allows dynein to move all chromosomes along the nuclear envelope to facilitate the search and pairing of homologous chromosomes for undergoing crossover. A key player in this process is the SUN1-KASH5 LINC complex that spans the nuclear envelope to link chromosomes to dynein. Despite the importance of chromosome-nuclear envelope tethering and motility in mammalian meiosis, a molecular mechanism for this phenomenon is still lacking. Understanding how SUN1-KASH5 performs its meiosis- specific function will generate new knowledge to improve the diagnosis and treatment of fertility disorders. Using a multi-disciplinary approach that includes biochemical/biophysical methods, fixed and live-cell microscopy, single-molecule TIRF microscopy, membrane protein reconstitution, and a specialized mouse meiosis model system, this proposal aims to understand how dynein moves chromosomes to facilitate homolog pairing during meiosis. Aim 1 of the proposal will determine the structural basis, the dynamics, and the meiosis-specificity of the KASH5-dynein interaction instrumental to crossover. Interrogation in mouse spermatocytes will complement the in vitro studies to reveal how the KASH5-dynein interaction helps uphold mouse fertility. Aim 2 of this proposal will determine the higher-order structures adopted by SUN1-KASH5 at the nuclear envelope and how they enable cytosolic dynein forces to move entire chromosomes in the nucleus. This Aim and the grant proposal culminate in the dissection of the molecular mechanism underlying infertility in humans caused by a mutation in the gene encoding KASH5. The proposed studies will reveal how dynein and LINC complexes come together to facilitate the essential process of crossover during mammalian meiosis.

哺乳动物减数分裂过程中染色体运动的机制 项目摘要/摘要 减数分裂是生殖线细胞分裂的一种专业形式，它产生了对性的单倍配子 生殖。减数分裂的关键步骤是同源染色体之间的重组，也称为 减数分裂跨界，将染色体适当分离为子细胞所需。不完善 种族隔离可以防止通过减数分裂进展，是不孕和流产的危险因素。详细的 了解减数分裂的交叉将增强对减数分裂的知识，并对人类产生影响 生殖生物学。减数分裂跨界的必不可少的是涉及连接的单元中的重塑过程 细胞核中的染色体通过蛋白质 - 蛋白质相互作用跨越核的蛋白质中的动力蛋白 信封。该事件允许动力蛋白沿核包膜移动所有染色体，以促进 搜索和配对同源染色体进行交叉。在此过程中的关键参与者是 sun1-kash5 linc综合体跨越核包膜将染色体与动力蛋白联系起来。尽管有 哺乳动物减数分裂中染色体核核包膜的束缚和运动的重要性，这是一种分子 这种现象的机制仍然缺乏。了解Sun1-Kash5如何进行减数分裂 - 特定功能将产生新知识，以改善生育障碍的诊断和治疗。 使用包括生化/生物物理方法的多学科方法，固定和活细胞 显微镜，单分子TIRF显微镜，膜蛋白重建和专门的小鼠 减数分裂模型系统，该提案旨在了解动力蛋白如何移动染色体以促进 减数分裂过程中的同源配对。提案的目标1将决定结构基础，动力学和 KASH5-DYNEIN相互作用的减数分裂特异性对跨界有帮助。鼠标中的询问 精子细胞将补充体外研究，以揭示Kash5-Dynein的相互作用如何帮助维护 小鼠生育能力。该提案的目标2将确定sun1-kash5采用的高阶结构 核包膜及其如何使胞质动力蛋白力在细胞核中移动整个染色体。 这个目的和批准提案最终在解剖中的分子机制中最终导致不育的分子机制 人类是由编码Kash5的基因中的突变引起的。拟议的研究将揭示Dynein和 LINC复合体融合在一起，促进哺乳动物减数分裂过程中的跨界基本过程。