Adapting to a Duplicated Genome

智力价值。高等生物偶尔会形成异常的个体，其整个基因蓝图比父母的基因蓝图翻了一番。虽然这些个体中的绝大多数很快就会灭绝，但在极其罕见的情况下，这样的“基因组复制”会产生新的谱系，这些谱系似乎意识到了拥有每个基因的“备用”副本带来的许多好处。在数亿年的进化过程中，这些罕见的“成功故事”共同成为新基因和新功能进化的最重要机制之一。开花植物(被子植物)比大多数分类群对基因组复制的耐受性更强--在过去的150-2亿年里，几乎所有的植物都经历了至少一次，有时是3-4次基因组复制，在过去的100-200万年中形成的许多新的多倍体是已知的，包括许多主要农作物。随着越来越多的被子植物基因组序列的获得，研究人员已经确定了一组基因的独特之处在于：(A)重复对中的一个成员(而不是两个成员)的损失率高于平均水平，(B)在谱系内和/或谱系之间的多个独立重复事件中命运趋同，以及(C)相关基因表达的随机程度更高。在这里，研究人员将开始对这些抗复制基因的一般群体和特定成员的适合度效应进行实证测试，寻找有助于基因组适应复制状态的途径和功能的遗传探测器。更广泛的影响。拟南芥的实验设施将加快对形成真核生物基因组的一些最重要的进化力量的分析，特别是使被子植物能够提供许多生态系统服务的生物多样性的分析，包括世界上大多数食物、饲料和纤维。更好地了解谱系对基因组复制的适应不仅具有根本意义，而且可能具有实际应用，无论是直接通过提高多倍体作物的生产力，还是间接通过减少在作物改良中广泛利用自然发生的种质资源的障碍。这项研究与学生和公众的教育密切相关，提供预科和研究生水平的培训机会，并有助于开发和实施基于研究的教材，以提高初中生对科学概念的成就、理解和掌握，并为“教师教教师”计划奠定核心。该项目由拟南芥2010项目共同资助。

Intellectual Merit.Higher organisms occasionally form aberrant individuals with their entire genetic blueprint doubled relative to that of their parents. While the vast majority of these individuals quickly go extinct, in exceedingly rare cases such "genome duplications" give rise to new lineages that appear to realize numerous advantages resulting from having "spare" copies of each gene. Across hundreds of millions of years of evolution, these rare "success stories" collectively are one of the most important mechanisms by which new genes and new functions evolve. Flowering plants (angiosperms) are more tolerant of genome duplication than most taxa - virtually all have experienced genome duplication at least once and sometimes 3-4 times in the past 150-200 million years, and many neo-polyploids formed in the past 1-2 million years are known including many major crops. With the sequences of a growing number of angiosperm genomes now available, the investigators have identified a population of genes that are distinctive in having (a) higher-than average rates of loss for one but not both member(s) of duplicate pairs, (b) convergent fates across multiple independent duplication events within and/or among lineages, and (c) a higher-than-random degree of correlated gene expression. Herein, the investigators will begin empirical tests of fitness effects associated with both the general population of these "duplication-resistant" genes and specific members, seeking genetic probes into pathways and functions contributing to adaptation of a genome to the duplicated state. Broader Impacts. The experimental facility of Arabidopsis will expedite analysis of some of the most important evolutionary forces shaping eukaryotic genomes, and in particular underlying the biodiversity that enables angiosperms to provide many ecosystem services including most of the worlds food, feed, and fiber. Better understanding of adaptation by a lineage to genome duplication is not only of fundamental interest but may also have practical applications, either directly by improving productivity of polyploid crops, or indirectly by mitigating obstacles to wider use of naturally-occurring germplasm resources in crop improvement. This research is closely tied to the education of students and the public, providing training opportunities at both pre- and postgraduate levels, and contributing to development and implementation of research-based educational materials to improve achievement, comprehension and mastery of scientific concepts by middle and high school students, also building the nucleus for a "teachers teach teachers" program.This project is co-funded by the Arabidopsis 2010 Project.