CAREER: Testing The Predictability of Flower Color Evolution at a Phylogenetic Scale in the Petunieae Clade (Solanaceae)

进化生物学家很早就认识到，物种可以使用同一组基因进化出许多不同的形式（表型）。对这种模式的一种解释是，新的形式可以通过基因调节的变化而产生，也就是说，这些基因在何时何地活跃的变化。虽然已知调控差异是眼睛和翅膀等复杂特征变化的基础，但尚不清楚这种调控假设适用的范围有多广，以及在某些情况下，基因本身的变化是否更重要。这个项目将通过追踪矮牵牛科（包括观赏矮牵牛在内的140个物种）的花色变化来解决这个问题。产生花色素的基因已经得到了很好的研究，这使得在大范围内描述与花颜色进化相关的遗传变化成为可能。作为这项工作的一部分，研究人员将为K-12学生和本科生的不同群体创建并呈现以颜色为主题的活动，以加强对生命之树中基因、途径和表型之间联系的教学和学习。该项目将通过三个具体目标来测试调节进化在矮牵牛属植物颜色多样化中的作用。第一个目标是利用转录组学数据构建的新系统发育来推断进化枝中花色变化的历史。在此系统发育框架的基础上，第二个目标将使用比较方法和生化分析来量化色素途径基因表达变化与颜色变化之间的进化关系。鉴于这些基因调控的模块化性质，第三个目标将测试基因表达在整个系统发育中的相关进化。这些目标将通过与巴西和阿根廷的植物学家合作来实现，他们将参与研究交流，促进知识和技术的共享。在地方范围内，研究活动将被整合到面向本科生和即将升入高中的学生的外展活动以及基于探究的课程模块中。这些创新的教学方法将与评估学习成果和指导改进的新工具相结合。

Evolutionary biologists have long recognized that species can evolve many different forms (phenotypes) using the same sets of genes. One explanation for this pattern is that new forms can arise by changes in gene regulation, that is, shifts in when and where those genes are active. Although regulatory differences are known to underlie changes in features as complex as eyes and wings, it remains unclear how broadly this regulatory hypothesis applies and whether, in some cases, changes in the genes themselves are more important. This project will address this question by tracing the evolutionary changes involved in flower color transitions across Petunieae, a group of 140 species that includes the ornamental petunias. The genes that produce floral pigments are well studied, making it possible to characterize the genetic changes associated with flower color evolution even at this broad scale. As a part of this work, the researchers will create and present color-themed activities to diverse groups of K-12 students and undergraduates in order to enhance teaching and learning about the connections between genes, pathways, and phenotypes across the tree of life.This project will test the role of regulatory evolution in the color diversification of Petunieae through three specific aims. The first aim will infer the history of flower color shifts in the clade using a new phylogeny constructed from transcriptomic data. Building on this phylogenetic framework, the second aim will use comparative methods and biochemical profiling to quantify the evolutionary relationship between changes in the expression of pigment pathway genes and color variation. Given the modular nature of the regulation of these genes, the third aim will test for correlated evolution of gene expression across the phylogeny. These aims will be carried out through collaborations with botanists from Brazil and Argentina, who will participate in research exchanges to foster the sharing of knowledge and techniques. At a local scale, the research activities will be integrated into outreach events as well as inquiry-based course modules for undergraduates and upward-bound high school students. These innovative teaching approaches will be coupled with new tools to assess learning gains and guide improvement.