Meiotic chromosome synapsis and recombination in yeast

酵母减数分裂染色体联会和重组

• 批准号: 7866579
• 负责人: Nancy E Kleckner
• 金额: $ 72.28万
• 依托单位: HARVARD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 2011-07-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7866579
• 关键词: Actins; Address; Aneuploidy; Area; Behavior; Cell Nucleus; Cells; Centromere; Chromatids; Chromatin; Chromosome Pairing; Chromosome Segregation; Chromosome Structures; Chromosomes; Color; Complex; Consensus; Cross-Over Studies; Cruciform DNA; DNA; Defect; Diagnosis; Diploidy; Down Syndrome; Ensure; Event; Excision; Exhibits; Female; Figs - dietary; Generations; Genetic; Genetic Crossing Over; Genetic Recombination; Germ Cells; Grant; Haploidy; Homologous Gene; Hot Spot; Image; Imagery; Individual; Infertility; Inherited; Kinetochores; Laboratories; Lead; Length; Life; Light Microscope; Link; Mechanics; Meiosis; Meiotic Recombination; Methodology; Microtubule-Organizing Center; Mitosis; Mitotic; Mitotic Cell Cycle; Modeling; Molecular; Motion; Nature; Nuclear; Nuclear Envelope; Optic Chiasm; Organism; Play; Ploidies; Positioning Attribute; Principal Investigator; Process; Prophase; Proteins; Reagent; Reproduction; Research; Resolution; Role; Series; Sister; Sister Chromatid; Staining method; Stains; Tail; Time; Touch sensation; Variant; Yeasts; base; cohesin; condensin; improved; interest; male; mutant; programs; segregation; spindle pole body; telomere

DESCRIPTION (provided by applicant): Meiosis is the specialized cellular program that produces haploid male and female gametes from a diploid parental cell as required for sexual reproduction. Our research addresses the central unique feature of this program, a complex series of interactions between maternal and paternal homologs, in three areas: (I) Recombination-independent pairing. This process, which also occurs in mitotically-dividing cells of some organisms ("somatic pairing"), is one of the major chromosomal behaviors for which there is no hint of the fundamental molecular mechanism. We will apply high-throughput 3C analysis to identify pairing "hot spots" and to examine the roles of specific variables of interest to pairing at a single defined locus. We will further analyze pairing interactions by motion correlation analysis of GFP-tagged loci in living cells. As time permits, we will begin to investigate the possibility of isolating (and then characterizing) paired molecules. (II) Recombination-related events. We will continue to analyze the basic nature of recombination at the DNA level by isolation and AFM visualization of recombination intermediates (notably double Holliday junctions) from a single recombination "hot spot". We will initiate a study of crossover interference by searching for functions which, when overproduced, increase or decrease the robustness of this process; also, we will try to distinguish among possible models for interference by creating, and assessing the effects of, a defined "loop" along a chromosome. Finally, we will continue to explore the roles of axis components for recombination by: studies of the "mitotic" cohesin Mcd1/Scc1/Rad21; high resolution analysis of local variations in protein localization via linked MNase studies; and further definition of chromosome organization via high resolution analysis of cohesin and condensin localization along pachytene chromosomes. (III) Motion and mechanics. We will improve our methodology for isolation of individual pachytene chromosomes as objects for mechanical studies. We will pursue our recent discovery of actin- and telomere-based chromosomal motion using existing reagents and by searching for "motion mutants". Defects in meiotic interhomolog interactions underlie many types of hereditary infertility as well as most chromosomal aneuploidies, all of which confer significant societal burdens (e.g. Downs syndrome). Basic understanding of these processes is crucial for diagnosis and potential amelioration of these conditions.

描述(申请人提供)：减数分裂是从二倍体亲本细胞产生单倍体雄配子和雌配子的专门细胞程序，是有性繁殖所需的。我们的研究解决了这个项目的核心独特之处，即母系和父系同源基因之间复杂的一系列相互作用，涉及三个方面：(I)重组独立配对。这一过程也发生在一些生物体的有丝分裂细胞(体细胞配对)中，是染色体的主要行为之一，其基本分子机制尚不清楚。我们将应用高通量的3C分析来确定配对的“热点”，并检查特定的感兴趣的变量在单个已定义的基因座上对配对的作用。我们将通过活细胞中GFP标记的基因座的运动相关性分析来进一步分析配对相互作用。在时间允许的情况下，我们将开始研究分离(然后表征)成对分子的可能性。(Ii)与重组有关的事件。我们将继续通过分离和原子力显微镜可视化重组中间产物(特别是双Holliday结)，在DNA水平上分析重组的基本性质。我们将通过寻找当过度生产时增加或降低这一过程的稳健性的功能来启动对交叉干扰的研究；同时，我们将试图通过沿着染色体创建并评估定义的“环”的影响来区分可能的干扰模型。最后，我们将通过以下方式继续探索轴组件在重组中的作用：“有丝分裂”粘附素Mcd1/Scc1/Rad21的研究；通过连锁的MNase研究对蛋白质定位的局部变异的高分辨率分析；以及通过粘附素和凝集素沿粗线期染色体的高分辨率分析进一步定义染色体组织。(Iii)运动和力学。我们将改进分离单个粗线期染色体的方法，作为机械研究的对象。我们将利用现有的试剂和寻找“运动突变体”来继续我们最近发现的基于肌动蛋白和端粒的染色体运动。许多类型的遗传性不孕症以及大多数染色体非整倍体都存在减数分裂同源基因间相互作用的缺陷，所有这些都会带来重大的社会负担(例如唐氏综合症)。对这些过程的基本了解对于这些疾病的诊断和潜在的改善至关重要。