Using FRET to Study RanGTP Gradients in Live Mouse Oocytes

Oocytes are extremely large cells that have to coordinate accurate chromosome segregation, asymmetric cytoplasm partitioning together with their own development as fertilizable gametes. For this, they undergo both global (cell cycle progression related) and local changes. It is therefore essential to be able to monitor local changes as they take place in live maturing oocytes. We describe here a method to follow RanGTP gradients using FRET technology in vivo.