CHARACTERIZATION OF ARABIDOPSIS TELOMERES

这项建议是一个长期项目的一部分，目的是了解 高等真核生物基因组的组织及其分子生物学 染色体功能成分，如端粒和着丝粒。 端粒是形成端粒终末的特殊结构。 真核细胞的染色体。这些结构对于复制是必不可少的 以及基因组的维护。端粒已经被广泛地研究在 较低的真核生物，但对高等真核生物知之甚少 端粒。我们最近从一个更高的真核细胞端粒中分离出 开花植物拟南芥，为研究提供了机会 作为模型系统的这种有机体的端粒区域。 我们将从端粒结构和功能两个方面进行研究。首先， 与A相邻的DNA序列的性质和组织。 我们将对桑叶的端粒进行研究。第二，通过什么机制 断裂的染色体末端获得新的端粒(即端粒愈合) 利用一种携带有一种基因的突变体进行研究 治愈的端粒。愈合后的端粒将被分离，其结构 与原始染色体的位置进行比较，以确定 治愈事件发生了。此外，修复后的端粒，它驻留 着丝粒的近端，将被作为潜在的工具进行研究 对拟南芥着丝粒结构的研究。

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.