G. Lavergne, B. Bertin, Y. Renaud
The understanding of the signals and intrinsic genetic determinants regulating the behaviour of muscle stem cells and their interactions with muscle niche represents a major challenge in developmental biology. Our experimental plan is designed to identify core genetic determinants of muscle stem cell-niche interactions applying a large set of genetic and imaging tools that allows following muscle stem cells in developing Drosophila embryos.
We will also apply cell- and time-specific translational profiling (TRAP method) of both the muscle stem cells and their muscle niche. Gained here knowledge will create a unique opportunity for uncovering genetic control of stem cell homing and niche-driven stem cell behavior.
In gene candidate approach strategy we will test Notch, Wingless/Wnt, EGF and FGF signalling pathways. We will use in vivo imaging (using our gapGFP and lifeAct-RFP sensor lines) to assess AMP cell shapes and their capacity to project filopodia/cytonemes and to contact surrounding muscles. The data that will be generated by this series of experiments will provide a complete overview on the activity of the key signalling pathways (timing and amplitude of activation) that play roles in muscle stem cell interactions with their niche. In genome-wide approach we will perform cell- and time-specific translational TRAP profiling using binary GAL4/UAS system for targeting polysomes of AMPs and three subpopulations of muscles (Lb-, Lms and slou-positive muscles) forming their niche.