P-307 - Establishment and evolution of a gene regulatory network controlling flower asymmetry

Abstract

Gene Regulatory Networks (GRN) dictate the patterns of expression in a cell. How changes in these networks lead to the emergence of phenotypic novelties is a major challenge in evolutionary developmental biology. The asymmetry of flowers constitutes a good model for studying the evolution of GRN, as this trait has emerged independently at least 25 times in the angiosperms. In Antirrhinum majus, the asymmetry of the flower depends on the regulation of a transcriptional module composed of three proteins: RADIALIS (RAD), DIVARICATA(DIV) and DIV-RAD-Interacting-Factors (DRIF). In the ventral part of the flower DIV interacts with DRIF to form a complex capable of binding DNA. On the dorsal part, RAD is expressed, and acts as a small interfering peptide binding to DRIF and preventing the formation of the DIV-DRIF complex. Our main purpose is to characterize the amino acids involved in protein-protein interactions between DIV-DRIF and DRIF-RAD. Based on sequence alignments and 3D model structure predictions, we will show the effect of mutagenized amino acid residues in the interaction between the different partners.