Acute control of intracellular trafficking through Rab GTPases in living tisssues in Drosophila. Rab GTPases are highly conserved master regulators of membrane trafficking in all eukaryotic cells. Recent discoveries have highlighted the importance of membrane trafficking in tissue development and homeostasis. In particular, endosomal regulation controls receptor signaling required for cell specification and coordinated multicellular tissue development. This project will utilize acute (in)activation of all 23 known functional Rab GTPases in various tissues of developing Drosophila to interrogate the role of Rab-dependent switches on tissue development and homeostasis in vivo.