The Role of Oxygen Supply in the Regulation of Neural Stem Cell Proliferation in the Brain of Drosophila

............................................................................................................................ 3 Resumen (Spanish) ............................................................................................................ 4 Introduction................................................................................................................................. 5 Oxygen, a metabolic double edge sword: balancing metabolic needs and toxicity .. 5 Stem cells and hypoxia ............................................................................................... 7 Neural stem cells are maintained in hypoxia ........................................................... 10 Hypoxia protects stem cells from oxidative damage ............................................... 12 The hypoxia response in mammals and insects ....................................................... 13 The optic lobe harbors proliferative neuroepithelial cells and it ́s progeny ............ 16 In insects oxygen is delivered to tissues through the tracheal system .................... 21 The developing larval brain is differentially tracheolated ....................................... 26 Hypothesis and aims of this thesis ........................................................................... 28 Objective .......................................................................................................................... 29 Specific Objectives ........................................................................................................... 29 Materials and Methods ................................................................................................... 31 Fly stocks .................................................................................................................. 31 Larval staging ............................................................................................................ 31 Larval dissection and immunostainings ................................................................... 31 Laser confocal microscopy ....................................................................................... 32 Image analysis .......................................................................................................... 32 Statistical analysis ..................................................................................................... 34 Tracheolar 3D reconstruction and measurements .................................................. 34 Oxygen sensor and ratiometric analysis .................................................................. 35 Hyperoxia and hypoxia treatment ........................................................................... 39