Comparative Genomics of A Rice Centromere

水稻着丝粒的比较基因组学

• 批准号: 0603927
• 负责人: Jiming Jiang
• 金额: $ 368.34万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0603927&HistoricalAwards=false
• 关键词: Comparative; Genomics; Rice; Centromere

The centromere is a cytologically (visually) defined entity with highly conserved functions. It is responsible for chromosomal sister chromatid cohesion and is the site for the assembly of kinetochore, a protein structure which links chromosomes to spindle fibers during cell division. In most multicellular eukaryotes, the centromeres are embedded within heterochromatin, a tightly packed form of DNA, and are associated with long tracts of satellite repeats in which genes are largely absent. Thus, the centromere is traditionally viewed as a highly heterochromatic and genetically silent chromosomal domain. Recent research work from the centromere of rice chromosome 8 (Cen8) as well as the neocentromeres (newly forming centromeric regions) from humans suggest that centromeres originated from genic regions. This project will focus on centromere evolution using rice Cen8 as a model. Specifically, this project will develop bacterial artificial chromosome (BAC)-based physical maps that span Cen8 in six diploid wild rice species and produce approximately one megabase of DNA sequence from each of the six centromeres. The functional boundary of the six centromeres will be determined using cytogenetic and molecular methods. The structural rearrangements and sequence divergence associated with the six centromeres will be revealed by comparative sequence analysis. Expression and evolution of Cen8-associated genes will be explored to understand how such genes adapt to a unique chromosomal domain. The results from this project will shed light on centromere evolution and will also build a foundation to study the evolution of genes located in heterochromatic and recombinationally-suppressed chromosomal domains. Access to Project OutcomesSequence data and gene annotation results will be made available to the public through GenBank, the project website (accessible through http://www.omap.org/) and community databases such as Gramene (http://www.gramene.org).

着丝粒是细胞学上（视觉上）定义的具有高度保守功能的实体。它负责染色体姐妹染色单体的凝聚，并且是着丝粒组装的位点，着丝粒是一种在细胞分裂期间将染色体连接到纺锤体纤维的蛋白质结构。 在大多数多细胞真核生物中，着丝粒嵌入异染色质（一种紧密堆积的DNA形式）中，并与长串的卫星重复序列相关，其中基因基本上不存在。 因此，传统上认为着丝粒是一个高度异染色质和遗传沉默的染色体结构域。 最近对水稻第8号染色体（Cen 8）的着丝粒以及人类新着丝粒（新形成的着丝粒区域）的研究表明，着丝粒起源于基因区域。 本项目将以水稻Cen 8为模型研究着丝粒的进化。 具体而言，该项目将开发基于细菌人工染色体（BAC）的物理图谱，该图谱跨越六个二倍体野生稻物种的Cen 8，并从六个着丝粒中的每一个产生大约一百万碱基的DNA序列。 将使用细胞遗传学和分子方法确定六个着丝粒的功能边界。 通过比较序列分析，揭示了与六个着丝粒相关的结构重排和序列差异。 Cen 8相关基因的表达和进化将被探索，以了解这些基因如何适应一个独特的染色体结构域。 该项目的结果将有助于阐明着丝粒的进化，也将为研究位于异染色质和重组抑制染色体结构域的基因的进化奠定基础。 公众可通过基因库、项目网站（可通过http：//www.omap.org/访问）和Gramene（http：//www.example.com）等社区数据库获得序列数据和基因注释结果。www.gramene.org