The role of RNA in centromere chromatin

描述（由申请人提供）：在表面上，着丝粒的概念很简单：染色体的一部分，在细胞分裂过程中为着丝粒组装和微管附着提供有利的染色质环境。然而，在分子水平上，着丝粒的概念相当模糊，涉及遗传和表观遗传因素之间复杂的相互作用。虽然在许多生物体中，着丝粒已经被定位到特定的遗传位点，并确定了它们的许多蛋白质成分，但关于是什么调节着丝粒的身份和功能的基本问题仍然没有答案。最近的证据表明，RNA在着丝粒染色质中起着重要作用。本研究的中心目标是了解染色质相关RNA对着丝粒调控和功能的贡献。我们选择使用模式植物物种玉米进行拟议的实验，因为它在研究着丝粒生物学方面具有独特的优势，并且因为我们可以根据需要定制资源和试剂。特别是，玉米在细胞学分析方面是无与伦比的，提供了多个表观遗传着丝粒异常的例子，并且是第一个检测到染色质结合着丝粒RNA的生物体的区别。以下具体目标将利用许多互补的实验方法，但将在很大程度上依赖于我们的优势和经验，通过深度测序来表征不同的RNA群体。1)着丝粒RNAome的研究与表征；2)着丝粒染色质中RNA参与规则的描述；3)新的着丝粒调控因子的鉴定。我们预计这项工作将导致与人类健康相关的几个重要研究领域取得进展，包括非整倍体的原因和与人类疾病的关系，基因治疗的小染色体的合理设计，以及对复杂遗传表观遗传现象的理解（基于从着丝粒提供的示例性和易于处理的系统中获得的知识）。

DESCRIPTION (provided by applicant): At a superficial level, the concept of a centromere is straightforward: the part of a chromosome that provides a favorable chromatin environment for kinetochore assembly and microtubule attachments during cell division. At a molecular level, however, the concept of a centromere is quite murky and involves a complex interaction between genetic and epigenetic factors. While in many organisms centromeres have been mapped to specific genetic loci and many of their protein components identified, fundamental questions about what regulates centromere identity and function remain unanswered. Recent evidence suggests that RNA plays an important role in centromere chromatin. The central goal of this proposed research is to understand the contribution of chromatin-associated RNA to centromere regulation and function. We have chosen to use the model plant species maize for the proposed experiments because of its unique advantages in studying centromere biology and because of the availability of resources and reagents tailored to our needs. In particular, maize is unrivaled for cytological analysis, provides multiple examples of epigenetic centromere deviants, and has the distinction of being the first organism in which chromatin-bound centromere RNA was detected. The following specific aims will make use of a number of complementary experimental approaches, but will rely substantially on our strengths and experience with characterization of diverse RNA populations through deep sequencing. 1) Survey and characterization of the centromere RNAome, 2) Delineation of the rules-of-engagement for RNA in centromere chromatin, and 3) Identification of novel centromere regulatory factors. We anticipate that this work will lead towards progress in several important areas of research connected to human health including causes of aneuploidy and relation to human disease, rational design of minichromosomes for gene therapy, and understanding of complex heritable epigenetic phenomena (based on the knowledge gained from the exemplary and easily tractable system provided by centromeres). PUBLIC HEALTH RELEVANCE: Modern medicine has greatly benefitted from scientific investigation into the molecular details of the cell and the genes that encode each component. What we hope to gain through our proposed research is a clearer understanding of the centromere, a fundamental cellular structure that is essential for accurate and reliable transmission of genes from one generation to the next. )