Genome Evolution in Diploid and Polyploid Cotton

PI：乔纳森·F·温德尔(爱荷华州立大学)联合PI：Adah Lesem-Ackerman(爱荷华州立大学)，Andrew H.Paterson(佐治亚大学)，Rod A.Wing(亚利桑那州立大学)植物基因组中的DNA数量在物种之间差异很大，幅度超过三个数量级。关于基因组大小的巨大差异产生的机制，人们了解的相对较少，但植物基因组的这一特征无疑对许多生物学领域和作物生产力具有基础性的重要性。为了弥补我们知识中的这一差距，该项目将在一个涉及二倍体和四倍体棉花物种的模型系统中，研究随着时间的推移，基因组大小变化的节奏(例如，规律性与间歇性猝发)、方向性(关于基因组收缩或扩张)和绝对规模。棉花属特别适合处理这项工作，但所收集的见解将延伸到所有植物。此外，这项工作还与该国主要农作物之一的产量和质量有关。这项研究涉及对基因组大小相差两倍的物种以及起源于这两个较小基因组的古代自然合并的四倍体物种(染色体数量增加一倍)的相同基因组区域进行测序。通过对大量DNA进行测序，并通过对染色体进行互补的分子分析，这项研究将揭示各种分子和遗传机制的相对作用，这些机制被认为是基因组大小变化的基础。这项研究还将有助于更好地理解具有大量重复DNA的植物基因组的组织和结构，并将提供对导致基因组进化的进化过程的无与伦比的洞察。在该项目期间，将开展一系列活动，加强和扩大对各级学生，包括K-12教育工作者的科学培训。获取项目成果序列数据将立即存入基因库(http://www.ncbi.nlm.nih.gov/).通过该项目开发的工具和资源将通过项目网站棉花门户(http://gossypium.info).)提供

PI: Jonathan F. Wendel (Iowa State University)Co-PIs: Adah Leshem-Ackerman (Iowa State University), Andrew H. Paterson (University of Georgia), Rod A. Wing (Arizona State University)The amount of DNA in plant genomes is highly variable among species, ranging by over three orders of magnitude. Relatively little is understood about the mechanisms by which this enormous variation in genome size arises, yet this feature of plant genomes undoubtedly has fundamental importance to many areas of biology and to crop productivity. To redress this gap in our knowledge, this project will address the tempo (e.g., regular vs. episodic bursts), directionality (with respect to genomic contraction or expansion), and absolute scale of genome size change, over time, in a model system involving diploid and tetraploid cotton species. The cotton genus is particularly well-suited to addressing this work, but the insights gleaned will extend to all plants. In addition, the work has relevance to the productivity and quality of one of the nation's leading crops. The study involves sequencing the same genomic regions from species that have genomes that vary twofold in size, as well as from a tetraploid species (with double the number of chromosomes) that originated from an ancient natural merger of these two smaller genomes. By sequencing large amounts of DNA, and by employing complementary molecular analyses of chromosomes, the research will reveal the relative roles of the various molecular and genetic mechanisms that are thought to underlie genome size change. The research also will lead to an improved understanding of the organization and architecture of plant genomes that have a great deal of repetitive DNA, and will provide unparalleled insight into the evolutionary processes responsible for genome evolution. During the course of this project, a spectrum of activities will be implemented that will enhance and broaden scientific training of students at all levels, including K-12 educators. Access to project outcomesSequence data will be deposited immediately in GenBank (http://www.ncbi.nlm.nih.gov/). The tools and resources developed through this project will be made available through the project web site, The Cotton Portal (http://gossypium.info).