Ecological genomics of developmental timing

植物生物学的主要目标之一是描述基因在序列水平上的变异如何产生表型变异。一个进展迅速的领域是描述遗传模式植物A.thaliana中调控基因的变异如何影响一种关键发育性状的变异，即从营养生长向生殖生长的过渡。尽管取得了这些进展，但尚不清楚这种变异在多大程度上是适应性的。我将调查在发育时机和对冷的发育敏感性(即这些特征与地理因素之间的关系)方面的倾斜性是否在拟南芥入侵种群中进化，与我在欧洲样本中检测到的倾斜性平行。入侵中的平行倾斜将是一个强有力的证据，表明拟南星的发育时序和发育敏感性的变化是适应性的。我还将调查两个主要的发育基因Fri和FLC在北美是否存在变异，并导致这些特征和适合度的地理差异。我的具体目标是：(1)在广泛的地理范围内收集一组北美A.thaliana生态型，并将它们用于一大组SNP标记，以评估种群遗传结构和连锁不平衡；(2)使用北美A.thaliana种群的这些SNP数据和发表的关于欧亚大陆样本的SNP数据，将北美入侵置于全球系统地理背景中；(3)测试北美种质之间是否在发育时序上进化了平行的克隆，如果它取决于FRI功能，(4)测试北美种质对冷的发育敏感性的平行地理差异，(5)将FRI和FLC的植物品系放入田间地点，并测量这些基因座上等位基因频率的自然变化。拟议的工作将支持培训几个HQP，并提高我们对发育计时、植物繁殖和入侵物种遗传学的知识，因为它评估了分子遗传和环境变异在塑造复杂性状中的作用，并测试了遗传和进化的平行性。

One of plant biology's major goals is to describe how variation in genes at the sequence level creates phenotypic variation. One area of rapid progress has been describing how variation at regulatory genes in the genetic model plant, A. thaliana, affects variation in a key developmental trait, the transition from vegetative to reproductive growth. Despite this progress, it is unclear how much of this variation is adaptive.   I will investigate whether clines in development timing and developmental sensitivity to cold (i.e., relationships between these traits and geographic factors) have evolved in invasive populations of A. thaliana, parallel to clines I detected in European samples. Parallel clines in invasives would be strong evidence that the variation in developmental timing and developmental sensitivity in A. thaliana is adaptive. I will also investigate if two major developmental genes, FRI and FLC, are variable in N. America and lead to geographic variation in these traits and fitness.   My specific aims are to: (1) Collect a set of North American A. thaliana ecotypes over a broad geographic range, and genotype them for a large set of SNP markers to assess population genetic structure and linkage disequilibrium, (2) Use these SNP data for N. American A. thaliana populations and published SNP data on Eurasian samples to place N. American invasives into a global phylogeographic context, (3) Test whether a parallel cline in developmental timing has evolved among N. American accessions, and if  it depends on FRI functionality, (4) Test for parallel geographic divergence in developmental sensitivity to cold in N. American accessions, (5) Plant lines variable for both FRI and FLC into field sites, and measure natural changes in allele frequency at these loci. The proposed work will support training several HQP and advance our knowledge of developmental timing, plant reproduction, and the genetics of invasive species because it evaluates the roles of molecular genetic and environmental variation in shaping complex traits, and tests for genetic and evolutionary parallelism.