Robustness and Stability of the Gene Regulatory Network Involved in DV Boundary Formation in the Drosophila Wing

Gene regulatory networks have been conserved during evolution. The Drosophila wing and the vertebrate hindbrain share the gene network involved in the establishment of the boundary between dorsal and ventral compartments in the wing and adjacent rhombomeres in the hindbrain. A positive feedback-loop between boundary and non-boundary cells and mediated by the activities of Notch and Wingless/Wnt-1 leads to the establishment of a Notch dependent organizer at the boundary. By means of a Systems Biology approach that combines mathematical modeling and both in silico and in vivo experiments in the Drosophila wing primordium, we modeled and tested this regulatory network and present evidence that a novel property, namely refractoriness to the Wingless signaling molecule, is required in boundary cells for the formation of a stable dorsal-ventral boundary. This new property has been validated in vivo, promotes mutually exclusive domains of Notch and Wingless activities and confers stability to the dorsal-ventral boundary. A robustness analysis of the regulatory network complements our results and ensures its biological plausibility

The Decapentaplegic morphogen gradient: from pattern formation to growth regulation.

Morphogens have been linked to numerous developmental processes, including organ patterning and the control of organ size. Here we review how different experimental approaches have led to an unprecedented level of molecular knowledge about the patterning role of the Drosophila melanogaster morphogen Decapentaplegic (DPP, the homologue of vertebrate bone morphogenetic protein, or BMP), the first validated secreted morphogen. In addition, we discuss how little is known about the role of the DPP morphogen in the control of organ growth and organ size. Continued efforts to elucidate the role of DPP in D. melanogaster is likely to shed light on this fundamental question in the near future