Abstract

While the signals regulating apoptosis during development are rather well known, what sets the precise spatio-temporal distribution of cell death and the adjustment of cell elimination to local perturbations is not well understood. Similarly, how cells eventually engage in apoptosis and how the removal of cells from epithelial layer is orchestrated through cell extrusion remained poorly understood, especially in vivo. In this seminar, I will present our recent attempt to dissect these two layers of regulation in the Drosophila pupal notum (a single layer epithelium). I will first describe the contribution of EGFR /ERK modulations by mechanics in the competitive elimination of cells by oncogenic clones. I will then illustrate how the same pathway help to fine tune the spatio-temporal distribution of cell elimination during homeostasis through local and transient feedbacks. Eventually I will describe our latest data on the regulation of cell extrusion by a caspase dependent disassembly of microtubules and their unexpected contribution to epithelial shape stabilization.