The Anatomy and Regulation of Mouse Recombination Hotspots.

小鼠重组热点的解剖和调控。

• 批准号: 8432888
• 负责人: John L. Cleveland
• 金额: $ 34.05万
• 依托单位: SCRIPPS FLORIDA
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8432888
• 关键词: Address; Anatomy; Applications Grants; Area; Backcrossings; Biological Assay; Biological Models; Biology; Cells; Chromatin; Chromatin Structure; Chromosomes; Chromosomes, Human, Pair 19; Cis-Acting Sequence; Coin; Complex; DNA; Data; Detection; Disease; Elements; Eukaryota; Event; Evolution; Female; Foundations; Generations; Genetic; Genetic Polymorphism; Genetic Recombination; Genome; Genomics; Germ Cells; Goals; Head; Homologous Gene; House mice; Hybrids; Inbred Mouse; Inbreeding; Individual; Infertility; Knowledge; Laboratories; Laboratory mice; Left; Libraries; Life; Malignant Neoplasms; Maps; Meiosis; Meiotic Recombination; Methodology; Methods; Modeling; Molecular Analysis; Molecular Machines; Mouse Strains; Mus; Nature; Nucleosomes; Nucleotides; Oocytes; Play; Population; Process; Recombinant Inbred Strain; Recombinants; Refractory; Regulation; Research; Resolution; Role; Sequence Analysis; Series; Site; Somatic Cell; Specificity; Staging; Structure; Testing; Trans-Activators; Variant; Yeasts; base; cis acting element; design; insight; male; mammalian genome; mouse genome; novel; public health relevance; research study; sperm cell

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is to define the anatomy and control of meiotic recombinogenic regions in mammalian genomes. Studies in a variety of models have demonstrated that recombination occurs in distinct regions coined hotspots during meiosis I. Indeed, it has been estimated that ~1-2% of the genomes of higher eukaryotes are recombinogenic, while the remainder of the genome is left in the "cold". However, very little is known regarding the cis-acting features that define recombination hotspots, nor how trans-acting factors control meiotic recombination in complex mammalian genomes. To define the anatomy and regulation of mouse recombination hotspots, in Aim 1 we will identify and characterize novel recombination hotspots in the mouse. We will focus our efforts on defining the recombination hotspots of mouse chromosome 19, and will characterize their rates and crossover/non-crossover (CO/NCO) profiles by direct sperm and oocyte typing, and by analyzing the genomic structure and plasticity of these loci in wild-house mouse populations. Our Preliminary Studies using recombinant inbred mice as a crossover library have established that we can rapidly identify bona fide recombination hotspots. The identification of recombination hotspots will allow us in Aim 2 to define the cis-acting features that direct recombination hotspot activity in the mouse. Our focus here is to interrogate the influence of local differences of cis-acting sequences at the cores of recombination hotspots. We will study nucleosome occupancy at hotspots and assess their role in influencing double strand break (DSB) initiation sites. Our preliminary data, using a refined FACS based method to purify the various meiotic stages, have provided exquisite direct insight into the nucleosome occupancy at recombination hotspots and the surrounding recombinogenic inert regions. Using the power of recombinant inbred strains we propose to assess the long-range genetic control of recombination hotspots activity depending on the interplay between the paired homolog they are faced to and their intrinsic local nature. Collectively, the proposed studies will provide fundamental knowledge regarding the anatomy and control of meiotic recombination hotspots in complex mammalian genomes, and they may also provide very important insights into how these molecular machines go awry in disease states such as infertility and cancer.

描述（由申请人提供）：拟议研究的长期目标是定义哺乳动物基因组中减数分裂重组区域的解剖结构和控制。在各种模型中的研究表明，重组发生在减数分裂的不同区域中。实际上，据估计，较高真核生物的基因组中约有1-2％具有重组性，而其余基因组则将其留在“冷”中。然而，关于定义重组热点的顺式作用特征，以及跨作用因子如何控制复杂哺乳动物基因组中的减数分裂重组，知之甚少。为了定义小鼠重组热点的解剖结构和调节，在AIM 1中，我们将识别并表征小鼠中新型的重组热点。我们将重点放在定义小鼠染色体19的重组热点上，并通过直接的精子和卵母细胞键入来表征它们的速率和交叉/非交叉/非交叉（CO/NCO）曲线，并通过分析野生小鼠种群中这些基因座的基因组结构和可塑性。我们使用重组近交小鼠作为跨界文库的初步研究已经确定，我们可以迅速识别真正的重组热点。重组热点的识别将使我们在AIM 2中定义直接重组热点活动的顺式作用特征。我们这里的重点是询问在重组热点核心的顺式作用序列的局部差异的影响。我们将研究热点处的核小体占用率，并评估它们在影响双链断裂（DSB）起始位点的作用。我们使用基于FACS的方法净化各种减数分裂阶段的初步数据，为重组热点和周围的重组惰性惰性区域时的核小体占用提供了精致的直接见解。使用重组近交菌株的力量，我们建议根据其面临的配对同源物与它们内在的局部性质之间的相互作用来评估重组热点活动的远程遗传控制。总的来说，拟议的研究将提供有关复杂哺乳动物基因组中减数分裂重组热点的解剖结构和控制的基本知识，并且它们还可能提供非常重要的见解，以了解这些分子机器在不育和癌症等疾病状态下如何出现问题。