Mechanism of Meiotic Recombination

减数分裂重组机制

• 批准号: 6558887
• 负责人: MICHAEL J LICHTEN
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6558887
• 关键词: DNA; DNA repair; DNA replication; Saccharomyces cerevisiae; centromere; chromatin; chromosomes; fungal genetics; genetic recombination; immunoprecipitation; meiosis; messenger RNA; microarray technology; microorganism culture; telomere

We continued research on the molecular mechanism of meiotic recombination in the yeast Saccharomyces cerevisiae,with a focus on three aspects of this complex biological process. We examined the initiation event in meiotic recombination, double-strand DNA break formation, with the aim of identifying the enzyme(s) responsible for break formation, their substrate requirements, and the factors that control the location and frequency of breaks. These factors include aspects of both chromatin and higher-order chromosome structure. A particular focus has been the role of chromosome structural elements, specifically centromeres and telomeres, in repressing double-strand break formation. We are also examining the relationship between meiotic DNA replication and recombination, and have demonstrated a direct mechanistic link between these two processes. We developed techniques to isolate unstable intermediates in meiotic recombination and are currently analyzing their structure. These latter experiments have demonstrated that crossover and noncrossover-associated repair of meiotic double-strand breaks proceed by distinct mechanisms, rather than being produced by alternate resolution of a common recombination intermediate. A second, related project involves the use of DNA microarrays to study gene expression and chromosome structure during meiosis, using mRNA and chromatin immunoprecipitation analyses. Towards this end, we are constructing microarrays covering the entire yeast genome in collaboration with four other research groups at the NCI.

我们继续研究酿酒酵母减数分裂重组的分子机制，重点关注这一复杂生物过程的三个方面。我们检查了减数分裂重组、双链 DNA 断裂形成的起始事件，目的是确定负责断裂形成的酶、其底物要求以及控制断裂位置和频率的因素。这些因素包括染色质和高阶染色体结构的方面。特别关注的是染色体结构元件，特别是着丝粒和端粒在抑制双链断裂形成中的作用。我们还在研究减数分裂 DNA 复制和重组之间的关系，并证明了这两个过程之间的直接机制联系。我们开发了分离减数分裂重组中不稳定中间体的技术，目前正在分析其结构。后面的这些实验表明，减数分裂双链断裂的交叉和非交叉相关修复是通过不同的机制进行的，而不是通过常见重组中间体的交替解析产生的。 第二个相关项目涉及使用 DNA 微阵列，通过 mRNA 和染色质免疫沉淀分析来研究减数分裂过程中的基因表达和染色体结构。为此，我们正在与 NCI 的其他四个研究小组合作构建覆盖整个酵母基因组的微阵列。