CHARACTERIZATION OF ARABIDOPSIS TELOMERES

本提案是一个长期项目的一部分， 高等真核生物基因组的组织和分子生物学 功能性染色体成分，如端粒和着丝粒。 端粒是形成染色体末端的特化结构， 真核生物染色体 这些结构对于复制 和基因组的维持。 端粒已经被广泛研究， 低等真核生物，但对高等真核生物知之甚少 端粒 最近，我们分离出一个高等真核生物的端粒， 开花植物拟南芥，提供了研究的机会， 这个生物体的端粒区域作为模型系统。 端粒结构和功能的两个方面将被研究。 一是 与A相邻的DNA序列的性质和组织。 将对拟南芥端粒进行研究。 第二，一个 断裂的染色体末端获得新的端粒（即，端粒愈合）将 使用A的染色体突变体进行研究。 thaliana， 修复端粒 愈合的端粒将被分离，其结构 与原始染色体位点进行比较，以确定 治愈事件发生了。 此外，修复后的端粒， 近端的着丝粒，将作为一个潜在的工具， 学习A。 拟南芥着丝粒结构。

This proposal is a part of a long-term project to understand the organization of higher eukaryotic genomes and the molecular biology of functional chromosome components, such as telomeres and centromeres. Telomeres are the specialized structures that form the termini of eukaryotic chromosomes. These structures are essential for the replication and maintenance of the genome. Telomeres have been extensively studied in lower eukaryotes but considerably less in known about higher eukaryotic telomeres. We have recently isolated a higher eukaryotic telomere from the flowering plant Arabidopsis thaliana, providing the opportunity to study the telomeric regions of this organism as a model system. Two aspects of telomere structure and function will be studied. First, the nature and organization of the DNA sequences that lie adjacent to A. thaliana telomeres will be investigated. Second, the mechanism by which a broken chromosome end acquires a new telomere (i.e., telomere healing) will be studied using a chromosomal mutant of A. thaliana which carries a healed telomere. The healed telomere will be isolated and its structure compared to that of the original chromosomal site to determine how the healing event took place. In addition, the healed telomere, which resides proximal to a centromere, will be investigated as a potential tool for studying A. thaliana centromere structure.