Research interests: quantitative biology of developing tissues
Signal transduction and morphogen gradients: Animal development relies on a handful of signaling pathways, which were discovered by genetic and biochemical techniques. Exploring the dynamics and function of these pathways is essentially impossible without mathematical models. We are combining imaging, computational, and genetic approaches in order to develop and experimentally test mathematical models of the Mitogen Activated Protein Kinase (MAPK) pathway, a key regulator of tissues in animals from worms to humans. Using the terminal patterning system in the early Drosophila embryo as an experimental model, we are examining how multiple levels of organization within the MAPK pathway control its dynamics and function. We discovered that the gradient of MAPK phosphorylation is established by a cascade of diffusion-trapping modules and are now studying how this gradient controls its biochemical and transcriptional targets.Epithelial patterning and morphogenesis: Epithelial morphogenesis, a process by which cellular sheets are folded into three-dimensional structures, relies on cell shape changes and rearrangements that control local tissue deformations. These spatially controlled cell behaviors reflect the spatial expression of "morphogenesis" genes responsible for cell adhesion, shape control, and force generation. The fact that the same morphogenesis genes are implicated in the formation of an amazing variety of structures suggests the possibility of a universal epithelial folding code. We are using the Drosophila eggshell morphogenesis as a versatile experimental model for exploring this idea. In the past, we used modeling and large-scale transcriptional profiling experiments to characterize the dynamics of two-dimensional pattern formation in this system. At this point, we are using imaging and biomechanical models to study how these patterns give rise to controlled tissue deformations.
