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.

哺乳动物减数分裂中染色体运动的机制 项目总结/摘要 减数分裂是生殖细胞分裂的一种特殊形式，产生有性生殖所必需的单倍体配子。 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 减数分裂交叉，需要染色体正确分离到子细胞中。不完善 分离阻止了减数分裂的进展，是不孕和流产的危险因素。详细 对减数分裂交叉的理解将有助于加深对减数分裂的认识， 生殖生物学减数分裂交换的关键是细胞中的重塑过程， 细胞质中的动力蛋白通过跨越细胞核的蛋白-蛋白相互作用 信封.这一事件允许动力蛋白沿着核被膜沿着移动所有染色体，以促进细胞的增殖。 寻找并配对同源染色体进行杂交。这一过程中的一个关键角色是 SUN 1-KASH 5 LINC复合物，跨越核膜将染色体连接到动力蛋白。尽管 哺乳动物减数分裂中染色体-核膜束缚和运动重要性 这一现象的机制仍然缺乏。了解SUN 1-KASH 5如何进行减数分裂- 特定功能将产生新的知识，以改善生育障碍的诊断和治疗。 使用多学科方法，包括生物化学/生物物理方法，固定和活细胞 显微镜，单分子TIRF显微镜，膜蛋白重建，和一个专门的小鼠 减数分裂模型系统，这项建议旨在了解动力蛋白如何移动染色体，以促进 在减数分裂过程中同源配对。该提案的目标1将确定结构基础、动力学和 KASH 5-动力蛋白相互作用的减数分裂特异性有助于交叉。小鼠询问 精母细胞将补充体外研究，以揭示KASH 5-动力蛋白相互作用如何有助于维持 小鼠生育能力。本提案的目标2将确定SUN 1-KASH 5采用的高阶结构， 核被膜以及它们如何使胞质动力蛋白力在细胞核中移动整个染色体。 这一目标和拨款建议最终在解剖不孕症的分子机制， 由编码KASH 5的基因突变引起的人类疾病。这项研究将揭示动力蛋白和 LINC复合物聚集在一起以促进哺乳动物减数分裂期间的交换的基本过程。