Evolution of Gene Networks: The Ranunculales Order as a Model Lineage for Evolutionary Innovations

进化研究的中心目标之一是理解基因调控网络的变化如何导致新的、复杂的特征的起源，或者简而言之：进化的新颖性是如何产生的？我们建议用毛滴目(毛滴目)新性状的起源作为模式系统来研究它们起源的分子性质。毛滴目是早期分枝的优生植物，包括形态不同的物种，如金凤花、罂粟、柱状植物和百灵鸟。毛滴目植物之所以特殊，是因为一些形态上的新奇事物反复进化，例如，刺生的花器官和左右对称，或花被减少。此外，新的花器官，从轮生、雌雄异株和风授粉退化为螺旋花叶序，在某些情况下是重复的。毛滴目中的许多物种对病毒诱导的基因沉默是敏感的，这使得在拟议的项目的后期阶段可以对候选基因的功能进行表征。我们建议对8个毛绒目物种的20个转录本进行测序，包括两个外类物种。对于没有基因组信息的物种，我们计划对它们的基因组进行测序。转录本将从各种组织中获得，包括不同发育阶段的花蕾、解剖的花器官、花瓣时间序列和营养组织。我们的最终目标是发现出现新的、通常是一致出现的特征所需的GRN模块。此外，我们希望在未来解开GRN模块被重复使用和选择以产生复杂的花卉形态的过程，从而推动物种多样化。在拟议的项目中，我们希望为毛滴目动物基因组和转录本的比较分析提供资源。这将为揭开新形态性状起源的遗传基础铺平道路。

One of the central goals of evolutionary research is to understand how changes in gene regulatory networks leads to the origin of novel, complex traits, or, in short: How do evolutionary novelties arise? We propose to use the origin of novel traits emerging in the order Ranunculales (buttercups) as model system to study the molecular nature of their origin. Ranunculales are early branching eudicots that comprise morphologically diverse species such as buttercups, poppies, columbines and larkspur. Ranunculales are special because several morphological novelties evolved repeatedly, e.g., spurred floral organs and zygomorphy, or the reduction of perianth. Moreover, novel floral organs, reduction to spiral floral phyllotaxy from whorled, dioecy, and wind pollination originated in this order, in some cases repeatedly. Many species within the Ranunculales are amenable to Virus-Induced Gene Silencing, which allows for functional characterization of candidate genes in later stages of the proposed project.We propose to sequence 20 transcriptomes of eight Ranunculales species (Eschscholzia californica, Papaver somniferum, Capnoides sempervirens, Pteridophyllum racemosum, Thalictrum thalictroides, Aquilegia coerulea, Nigella damascena and Staphisagria picta) that encompass these novelties including two outgroup species. For the species without genome information available, we plan to sequence their genomes. The transcriptomes will be obtained from a variety of tissues, including floral buds at different developmental stages, dissected floral organs, petal time-series and vegetative tissues. Our ultimate goal is to uncover the GRN modules required for the emergence of novel, often convergently emerging traits. Furthermore, we hope to unravel in the future the processes by which GRN modules are reused and coopted to generate complex floral morphologies and thus drive species diversification. In the proposed project, we want to provide the resources for comparative analysis of genomes and transcriptomes in Ranunculales. This will pave the way to unravel the genetic base novel morphological trait origin.