The main goal of this project is to understand the regulatory logic underlying the control of leaf shape in plant focussing on a set of key regulators, the CUCs transcription factors. The diversity of shape seen in the plant kingdom is astonishing. How from small groups of cells encompassed in a primordium such variety of shape can be generated? The answer is maybe lying in the intricate regulatory network controlling cell fate and boundaries. It is believed indeed that changes in gene regulatory network (GRN) grandly contribute to morphological changes and therefore represent large evolutionary targets potentially producing important effects with limited pleiotropy (Doebley JF et al., 2006; Carroll SB, 2008; Arnaud et al., 2011). The proposed project is an opportunity to understand the regulatory logic of transcription factors, the combinatorial regulatory code governing a developmental process. To understand how genes control shape - a question relevant to all aspect of developmental biology and with important implications on crop improvement - we propose to focus on one of the simplest plant structure, the leaf. Grasping the mechanisms regulating leaf development will require the understanding of the regulatory logic of CUP-SHAPED COTYLEDON (CUCs), which are master regulators of leaf shape. This fundamental research project will use a highly integrative approach combining molecular, genetic and computational approaches to gather information relative to GRN controlling leaf serration. Such a multi-disciplinary approach will allow us to define the GRN controlling leaf margins at the molecular level, and use these data to generate a high-resolution model of the GRN that control leaf morphology. The identification of new components in the leaf shape GRN and the generation of computational model of the regulatory interactions will strengthen current knowledge on leaf development and widen the perspective for crop improvement, having therefore a high impact in the area of growth and development.