Scheme of different RGC translocation scenarios. (A) Somal translocation of RGC inheriting the basal process, a mode used by 80% of cells. The RGC translocates basally faster than the sister cell. Fine positioning, during which cells lose their apical processes and eventually form axons, follows. (B) Somal translocation of RGC not inheriting the basal process, a mode used by 20% of cells. The RGC initially lags behind the sister cell. Later, it regrows the basal process and overtakes it. Translocation is less efficient than in A. The fine positioning phase is shorter than in A. (C) The multipolar migratory mode occurs after MT destabilization or Arp2/3 inhibition and in rare cases in control cells. After loss of basal process attachment, the RGC detaches its apical process and increases protrusive activity. It then moves basally using the multipolar mode. This movement is less efficient than in A. Axon formation and RGC layer establishment are not affected. (D) No translocation. In case RGC translocation is inhibited, cells are able to differentiate at ectopic locations, which has severe consequences for later retinal lamination.