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

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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.