Our aim is to better understand the vesicle trafficking in the lysosomal system (including autophagy, endocytosis and related pathways). To achieve this, we use a combination of ex vivo fluorescent microscopy, electron microscopy and biochemical methods. Our main model organism is the fruit fly (Drosophila melanogaster) with its vast and unique genetical toolkit. We also use human cell lines as they represent the complexity of the human cells.