Mosaic analysis of BMP receptors to study intercellular communication during Drosophila melanogaster pupal wing development

Abstract

During the metamorphosis of Drosophila melanogaster, complex structures and organs develop from relatively simple clusters of undifferentiated cells. The development of wing veins in the fly involves a variety of morphogens, signalling molecules that form gradients of activity across tissues. One of such morphogens, BMP type ligand, Decapentaplegic (Dpp), is expressed within the developing wing veins and is spatially restricted by its receptor Thickveins (Tkv), thereby maintaining a short-range signal. The precise mechanisms that prevent Dpp from diffusing remain unclear. This study used a heat shock inducible FLP-FRT system to generate a random mosaic of constitutive active Tkv clones, driven by the endogenous enhancer, aiming to observe how mosaic clones affect surrounding cells with wild type Tkv receptors. The results show that a post receptor activation signal initiates the formation of a Tkv barrier surrounding Dpp signal positive cells and that lateral exhibition of Tkv might play a role in limiting the Dpp diffusion range. These findings contribute to a better understanding of how spatial restriction of morphogen signalling is achieved during wing patterning in Drosophila development.