Recombination pathway and partner choices during meiosis

减数分裂过程中的重组途径和伴侣选择

• 批准号: 10224865
• 负责人: Diana Elizabeth Libuda
• 金额: $ 36.64万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2023-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10224865
• 关键词: Biological Assay; Biological Models; Caenorhabditis elegans; Cell division; Cell physiology; Chromosome Segregation; Chromosome Structures; Chromosomes; Congenital Abnormality; DNA; DNA Double Strand Break; DNA Repair; Development; Diploidy; Double Effect; Ensure; Event; Foundations; Genetic; Genetic Recombination; Genetic Variation; Genome; Germ Cells; Goals; Haploidy; Health; Human; Image; Infertility; Knowledge; Malignant Neoplasms; Meiosis; Meiotic Recombination; Methods; Microscopy; Molecular Profiling; Monitor; Organism; Outcome; Pathway interactions; Process; Prophase; Proteins; Research; Resolution; Sister Chromatid; Spontaneous abortion; System; ds-DNA; egg; genome integrity; genomic locus; in vivo; preference; prevent; programs; repaired; sperm cell

Research Summary Recombination between chromosomes is required to generate genetic variation, maintain genome integrity through the repair of double strand DNA breaks (DSBs), and ensure proper chromosome segregation during meiosis, the specialized cell division program by which diploid organisms generate haploid gametes such as sperm and eggs. Perturbations in recombination can compromise these basic cellular functions, ultimately leading to cancer, infertility, or birth defects. Meiotic recombination is initiated by DSBs, which are repaired using meiosis-specific mechanisms that favor utilization of the homologous chromosome (instead of the sister chromatid) as the recombination partner and that promote a crossover outcome of the DSB repair process, which is required for promoting proper chromosome segregation during meiosis. Although repair of DSBs with the appropriate template (homologous chromosome) is necessary for proper chromosome segregation and genome integrity, our knowledge about how germ cells achieve this template preference in the presence of nearly identical sequences (sister chromatids) is limited. The goal of our research program is to understand how chromosomes are able to access distinct recombination pathways and partners depending on the chromosomal and cellular context to ensure faithful genome inheritance. Using Caenorhabditis elegans as a model system, we have developed an assay to monitor repair of an induced DSB with the sister chromatid during meiotic prophase progression in vivo. We now have evidence for the presence of a switch in repair partner preferences from the homologous chromosome to the sister chromatid during late meiotic prophase. In this proposal we will begin to lay the foundation for understanding how specific DSB repair pathways and partners are engaged and regulated during meiosis. To determine how these different repair partner choices are regulated, we will identify the molecular signatures, chromosomal features, and proteins associated with these different repair outcomes. Further, we will use live imaging, a new live genomic locus tracking system, and genetics to determine the how early DSB repair dynamics influence DSB repair outcomes. Further, we will use superresolution and high-resolution microscopy methods to assess the effects of DSB repair on meiotic chromosome structures and DNA organization. Overall, these studies will reveal how recombination pathway and partner choices ensure that chromosomes form the connections necessary for chromosome segregation and repair DSBs for maintaining genomic integrity during sperm and egg development.

研究总结 染色体之间的重组是产生遗传变异、维持基因组完整性所必需的 通过修复双链DNA断裂(DSB)，并确保在 减数分裂，二倍体生物产生单倍体配子的特殊细胞分裂程序，如 精子和卵子。重组中的扰动最终会损害这些基本的细胞功能 导致癌症、不孕不育或先天缺陷。减数分裂重组是由DSB启动的，DSB被修复 使用有利于利用同源染色体(而不是姊妹染色体)的减数分裂特定机制 染色单体)作为重组伙伴并且促进DSB修复过程的交叉结果， 这是在减数分裂过程中促进适当的染色体分离所必需的。虽然使用DSB修复DSB 适当的模板(同源染色体)对于正确的染色体分离和 基因组完整性，我们关于生殖细胞如何在存在 几乎相同的序列(姐妹染色单体)是有限的。我们研究计划的目标是了解 染色体如何能够访问不同的重组途径和配对取决于 染色体和细胞背景，以确保忠实的基因组遗传。利用秀丽隐杆线虫作为一种 模型系统，我们已经开发了一种方法来监测诱导的DSB与姐妹染色单体的修复 在体内减数分裂前期进展过程中。我们现在有证据证明存在维修中的开关 在减数分裂后期前期，伴侣偏好从同源染色体到姐妹染色单体。在……里面 这一建议我们将开始为了解具体的DSB修复路径和 在减数分裂过程中，伴侣参与并受到调控。要确定这些不同的维修合作伙伴选择如何 ，我们将确定分子特征、染色体特征和与之相关的蛋白质 这些不同的修复结果。此外，我们将使用实时成像，一种新的实时基因组轨迹跟踪系统， 以及遗传学，以确定早期DSB修复动力学如何影响DSB修复结果。此外，我们还将 用超分辨和高分辨显微镜方法评估DSB修复对减数分裂的影响 染色体结构和DNA组织。总的来说，这些研究将揭示重组途径是如何 而伴侣的选择确保了染色体形成染色体分离所必需的连接 并修复DSB，以在精子和卵子发育期间保持基因组的完整性。