Phylogenetics an morphological diversification in capparaceae, cleomaceae, and brassicaceae

尽管我们对开花植物形态的多样性非常着迷，但我们对这种变化是如何产生的理解有限。我的研究目的是为了更好地理解两个关键性状差异的机制：果实结构和花的对称性。芥菜科中有一个被称为芸苔科的类群，它很重要，因为它包括作物物种（如油菜、西兰花），而且果实通常是分节的，这一特征极大地改变了种子的传播方式。种子在作物中的传播和控制转基因作物系统中的基因流动的重要性日益增加，以及自然生态系统中引种物种的日益流行，需要对果实发育遗传学和进化有详细的了解。刺山柑科的物种在花的形态上表现出令人印象深刻的变化，包括花的对称上的许多变化。这一性状对传粉者的相互作用有重要影响，包括促进物种形成和多样化。最后，我们想知道基因调控的变化是如何导致形态差异的——这是生物学中的一个关键问题。我们采取了全面的方法，包括：(1)利用DNA变异来阐明形态不同植物之间的关系，以了解形式的转变；(2)对一系列物种进行详细的发育研究，以确定发育模式；(3)利用分子测年来确定事件的进化时间；(4)进行遗传研究，以研究基因表达的差异如何导致形态变化。我重点研究的两个类群，芸苔科和刺山柑，都与遗传植物模式拟南芥密切相关，这将极大地促进遗传研究。令人惊讶的是，这些群体在很大程度上被忽视了，因为它提高了我们对这一重要遗传模型的形态多样性的理解。

Despite our fascination with the diversity of forms observed in flowering plants, our understanding of how this variation has arisen is limited.  The goal of my research is to better understand the mechanisms underlying differences in two key traits: fruit structure and floral symmetry.  A group within the mustard family, called the Brassiceae, is important because it includes crop species (e.g. canola, broccoli) and because the fruits are often segmented, a trait that dramatically alters how their seeds are dispersed.  The increasing importance of seed dispersal in crop plants and controlling the gene flow in genetically modified crop systems, and the increasing prevalence of introduced species in natural ecosystems, necessitate a detailed knowledge of fruit developmental genetics and evolution.  Species in the caper family reveal an impressive variation in floral form, including many changes in floral symmetry.  This trait has a significant impact on pollinator interactions including promoting speciation and diversification.Ultimately, we would like to know how changes in gene regulation have lead to morphology differences - a key question in biology.  We take a comprehensive approach that includes: (1) using DNA variation to elucidate relationships among morphologically distinct plants in order to understand transitions in form, (2) conducting detail developmental studies on a range of species to determine developmental patterns, (3) using molecular dating to determine the evolutionary timing of events, and (4) conducting genetic studies to examine how differences in gene expression may lead to morphological variation.  The two groups that I focus on, the Brassiceae and the capers, are both closely related to the genetic plant model, Arabidopsis, which will greatly facilitate genetic studies. Surprisingly, these groups have largely been overlooked with regards to improving our understanding of morphological diversity surrounding this important genetic model.