Centrosome migration into the Drosophila oocyte is independent of BicD andegl, and of the organisation of the microtubule cytoskeleton

During early Drosophila oogenesis, one cell from a cyst of 16 germ cells is selected to become the oocyte, and accumulates oocyte-specific proteins an d the centrosomes from the other 15 cells. Here me show that the microtubul e cytoskeleton and the centrosomes follow the same stepwise restriction to one cell as other oocyte markers. Surprisingly, the centrosomes still local ise to one cell after colcemid treatment, and in BicD and egl mutants, whic h abolish the localisation of all other oocyte markers and the polarisation of the microtubule cytoskeleton, In contrast, the centrosomes fail to migr ate in cysts mutant for Dynein heavy chain 64C, which disrupts the fusome, Thus, centrosome migration is independent of the organisation of the microt ubule cytoskeleton, and seems to depend instead on the polarity of the fuso me.