BE-GenEn: Genomics of Adaptation to the Biotic and Abiotic Environment in Aquilegia

博士们已获得一笔赠款。Scott Hodges, Elena Kramer, Magnus Nordborg， Jeff Tomkins和Justin Borevitz（分别来自加州大学圣巴巴拉分校，哈佛大学，南加州大学，克莱姆森大学和芝加哥大学），研究耧斗菜属（Aquilegia）对环境的适应。地球上生命的进化被许多适应性辐射的例子所打断。这些戏剧性的事件迅速创造了大量的生物多样性，并通过快速的物种形成以及对众多生态位的形态和生理适应来证明。开花植物水仙属的物种经历了最近的适应性辐射，并提供了一个独特的机会来研究适应的分子遗传变化。这个属的物种有着惊人的不同的花形态和对不同传粉者的专门化。此外，从沿海森林到沙漠泉再到高山，物种的栖息地也有很大的不同。因为属中的任何两个物种都可以成功杂交，所以有可能解剖任何物种的任何性状的遗传基础。通过开发该属的一系列分子遗传资源，该项目将为广泛的科学家社区的大量研究提供基础设施。比较基因组学研究将特别容易，因为Aquilegia是毛茛科（Ranunculaceae）的一员，在拟南芥（Arabidopsis）等毛茛模式系统和水稻等单子叶模式系统之间几乎是等距的。Aquilegia的基因组是开花植物中最小的基因组之一，约为350兆bp，这一事实将促进所有这些研究。该项目的具体目标是评估三个重要性状的遗传基础：对特定传粉者的形态适应、对开花时间的生理适应和对不同土壤/生境的适应。这些目标将通过开发一种Aquilegia， a . formosa的物理基因组图谱，以及大规模的EST序列数据库和转化系统来实现。EST序列将定位到物理图谱上，用于构建寡核苷酸阵列，用于表达研究和基于阵列的性状定位。影响花取向的基因座的精细定位和克隆将通过基于阵列的定位以及关联定位和表达研究来完成。为了研究水仙花开花时间的进化，我们将克隆候选基因，并对其表达模式和进化进行分析。为了确定适应不同栖息地的遗传结构，将创建由台湾一枝和短毛一枝杂交而成的重组自交系，精细地绘制它们的断点，并在每个亲本物种的栖息地中确定它们的适应性。

A grant has been awarded to Drs. Scott Hodges, Elena Kramer, Magnus Nordborg, Jeff Tomkins and Justin Borevitz (of the University of California, Santa Barbara, Harvard University, University of Southern California, Clemson University and University of Chicago respectively) to study adaptation to the environment in the columbine genus, Aquilegia. The evolution of life on earth has been punctuated by numerous examples of adaptive radiation. These dramatic events quickly create a large amount of biodiversity and are evidenced by rapid speciation along with morphological and physiological adaptations to numerous ecological niches. Species in the flowering plant genus Aquilegia have undergone a very recent adaptive radiation and present a unique opportunity to investigate the molecular genetic changes underlying adaptations. Species in this genus have spectacularly different floral morphologies with specializations to different pollinators. In addition, species differ radically in their habitats ranging from coastal forests to desert springs to the high alpine. Because any two species in the genus can be successfully crossed it is possible to dissect the genetic basis for essentially any trait in any species. By developing an array of molecular genetic resources for this genus, this project will provide the infrastructure for a host of studies by a broad community of scientists. Comparative genomic studies will be particularly amenable because Aquilegia is a member of the basal eudicot family Ranunculaceae, which is nearly equidistant between the eudicot model systems such as Arabidopsis and the monocot model systems such as rice. All of these studies will be facilitated by the fact that the genome of Aquilegia is among the smallest for a flowering plant at about 350 Mbp. The specific goals of this project are to evaluate the genetic basis of three important traits, morphological adaptation to a specific pollinator, physiological adaptation for flowering time and adaptation to different soil/habitats. These goals will be accomplished by developing a physical map of the genome of one species of Aquilegia, A. formosa, along with a large-scale EST sequence database and a transformation system. The EST sequences will be localized to the physical map and used to construct oligonucleotide arrays for expression studies and array-based mapping of traits. Fine-mapping and cloning of a locus affecting flower orientation will be accomplished with array-based mapping along with association mapping and expression studies. To investigate the evolution of flowering time in Aquilegia, candidate genes will be cloned and their expression patterns and evolution will be characterized. To determine the genetic architecture for adaptations to different habitats, recombinant inbred lines from a cross between A. formosa and A. pubescens will be created, their breakpoints finely mapped and their fitness determined in each parental species' habitat.