Affiliations: 1) University of Basel, Basel, Switzerland; 2) Brown University, Providence, USA
Keywords: g. wing disc; g. CRISPR/Cas9
One of the key processes of embryonic development is the establishment of differentiation patterns. These, in turn, tightly depend on cell-cell communication, often mediated by secreted signalling molecules. Morphogens are a paradigmatic example: upon secretion from a localized source, morphogens disperse forming concentration gradients that will activate distinct gene targets at different concentration thresholds. Bone Morphogenetic Proteins (BMPs) act as indispensable morphogens in multitude of scenarios. Different BMPs are often expressed in the same tissue acting, potentially, in a combinatorial manner, forming both homo- and heterodimers. While the biochemical properties of the different ligand combinations have been extensively studied, little is known about the impact that they have on morphogen gradient formation.
In the Drosophila developing wing there are two BMP-type ligands, Decapentaplegic (Dpp) and Glass bottom boat (Gbb). It has been proposed that they can form both hetero and homodimers. Although is assumed that wing development mainly requires Dpp, Gbb has also been shown to be involved in patterning and growth, despite relatively weak phenotypes. Based on genetic analysis it has been suggested that Dpp and Gbb exhibit different effective signalling ranges. However, dissection of these process exceeds the power of current genetic tools. We have generated ad hoc CRISPR reagents and protein binder-based tools to visualize and manipulate the dispersal of Gbb and Dpp.