Sphingosine-1-Phosphate Receptor 1 regulates competition dependent astrocyte morphogenesis and tiling in murine cortex

regulates astrocyte morphogenesis in a cortical layer specific manner. Using astrocyte-specific S1PR1 knock out mouse models and adeno-associated viral labeling methods, we show that S1PR1 is crucial in establishing competition driven astrocyte tiling and morphogenesis in the developing brain. Furthermore, we show that JAK-STAT3 signaling regulates neuronal contact induced expression of S1PR1 in cocultured astrocytes. These studies therefore uncover a lipid signaling receptor as a major regulator of astrocyte morphogenesis and tiling in murine cortical layers.