Phenotypic and genetic variation in Biscutella didyma and other Brassicaceae and adaptation to environmental change - a combined ecological-genomic approach

地方适应和地理分隔对于多样性的进化至关重要，最近对人类的全基因组分析揭示了遗传差异空间分布的证据。然而，塑造这些模式的力量只在少数情况下被理解，因为人们通常不知道遗传分化最初是如何产生的。自上而下的方法可以指出基因组的区域选择在最近的过去，但他们很少确定负责的基因和选定的性状。相反，关于当地适应的生态学研究很少利用基因组学的进展。在这里，我们将联合收割机现代进化生态学与最先进的基因组学相结合，研究了双小盾藻和其他兰科物种的实时进化。我们利用一个独特的实地实验，以测试全基因组分化沿着干旱梯度，研究是否全基因组的选择签名已暴露于人工降水制度的人口中是可检测的，以及是否响应于选择梯度的表型变异对应于理论预测。在第一阶段结果的基础上，我们将研究B中三个独立干旱渐变系的全基因组选择标记。didyma和四个相关物种。此外，我们将表型另外六个相关的物种沿着梯度。我们将扩大我们的性状测量新的性状，遗传途径是众所周知的，并表现出沿沿着气候梯度：气孔和毛状体密度，草食动物的防御和自交率。通过关注具有良好特征的遗传网络的适应性特征，我们不仅可以识别选定的基因，还可以回答如何在独立比较中实现适应性潜力。我们的发现将使我们能够在预测的气候变化下开发适应能力模型。

Local adaptation and geographic separation are crucial for the evolution of diversity, and recent whole-genome analyses in humans have revealed evidence for spatial distribution of genetic differences. The forces shaping these patterns are, however, only understood in few cases, because it is generally not known how genetic differentiation arises in the first place. Top-down approaches can point to regions of the genome under selection in the recent past, but they rarely identify the responsible genes and the selected traits. Conversely, ecological studies on local adaptation have made little use of the progress in genomics. Here, we combine modern evolutionary ecology with state-of-the-art genomics to study real-time evolution in Biscutella didyma and other Brassicaceae species. We utilize a unique field experiment to test genome-wide differentiation along an aridity gradient, study whether genome-wide signatures of selection are detectable in populations that have been exposed to manipulated precipitation regimes, and whether phenotypic variability in response to selection gradients corresponds to theoretical predictions. Building on the results from phase one, we will study genome-wide selection signature in three independent aridity clines in B. didyma and four related species. In addition, we will phenotype another six related species along the gradients. We will expand our trait measurements to new traits for which genetic pathways are well-known and which exhibit clines along the climate gradient: stomata and trichome density, herbivore defense, and selfing rates. By focusing on adaptive traits with well-characterized genetic networks, we will not only identify selected genes, but answer to how adaptive potential is being realized in independent comparisons. Our findings will enable us to develop models of adaptive capacity under predicted climate change.