A Comparative Genomics Investigation of Unprecedented Haplotype Variability in Maize

玉米前所未有的单倍型变异的比较基因组学研究

• 批准号: 0320683
• 负责人: Hugo Dooner
• 金额: --
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2009-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0320683&HistoricalAwards=false
• 关键词: Comparative; Genomics; Investigation; Unprecedented; Haplotype

Maize is probably the most diverse of all crop species. The most significant practical consequence of the huge genetic diversity within maize is the phenomenon of hybrid vigor (heterosis). Distantly related lines tend to produce highly vigorous F1 hybrids, which are planted across the entire Corn Belt. Yet, the molecular basis of hybrid vigor is not understood. However, analysis of allelic regions between inbreds has indicated that the same interval differs in sequence and gene content. Therefore, it has been hypothesized that hybrid vigor could be explained on the basis of different, yet complementing, gene sets in the two inbreds. To investigate the extent of occurrence of such plus-minus type changes, the genomic organization of two gene-dense genomic regions, bz and fie2-orp2, will be investigated in a group of 12 inbred lines, races, and relatives of maize. Twelve size-fractionated, NotI BAC libraries will be constructed and bz and fie2 clones will be isolated and sequenced from each library. Thus, 1 Mb of DNA sequence will be generated and deposited in central sequence repositories. The distribution of polymorphism will be examined with respect to differences among heterotic groups and to the potential role of inbreeding in genome rearrangement. BAC data will be analyzed with population genetic methods to contrast evolutionary histories between genes and examine the relationship between linkage disequilibrium and recombination.Specific deliverables are:1. BAC libraries specific to the bz and fie2-orp2 regions from 12 accessions2. 1 Mb sequence data deposited in GenBank and maizeGDB3. Characterization of gene presence/absence and polymorphisms in the selected regions4. Analysis of recombination rates across multiple accessions for the specific regions

玉米可能是所有作物品种中最多样化的。 玉米巨大遗传多样性最重要的实际后果是杂种优势现象（杂种优势）。 亲缘关系较远的品系往往会产生活力极强的 F1 杂种，并在整个玉米种植带种植。 然而，杂种活力的分子基础尚不清楚。然而，对近交体之间等位基因区域的分析表明，相同的区间在序列和基因内容上有所不同。 因此，有人假设杂种优势可以根据两个近交系中不同但互补的基因组来解释。 为了研究这种正负类型变化发生的程度，将在一组 12 个玉米自交系、种族和近缘种中研究两个基因密集的基因组区域 bz 和 fie2-orp2 的基因组组织。 将构建 12 个大小分级的 NotI BAC 文库，并从每个文库中分离 bz 和 fie2 克隆并进行测序。 因此，将生成 1 Mb 的 DNA 序列并将其存放在中央序列存储库中。 将根据杂种优势群体之间的差异以及近交在基因组重排中的潜在作用来检查多态性的分布。 采用群体遗传学方法对BAC数据进行分析，对比基因之间的进化历史，检验连锁不平衡与重组之间的关系。具体成果有： 1． 来自 12 个种质的 bz 和 fie2-orp2 区域特异的 BAC 文库2。 1 Mb 序列数据存放在 GenBank 和 maizeGDB3 中。 选定区域中基因存在/缺失和多态性的表征4。 特定区域多个种质的重组率分析