Stabilized MTs are important for RGC translocation. (A, left) Example of EB3 comets in progenitor cells. Bar, 5 µm. (Right) Progenitor EB3 comet speed median = 0.23 µm/s; n = 11 cells, 60 comets. RGC EB3 comet speed median = 0.13 µm/s; n = 6 cells, 24 comets; *, P = 0.0103, Mann-Whitney U test. Bars represent median and interquartile ranges. (B) Live imaging of MTs in translocating RGCs. Time is shown in hours and minutes. White dots, RGC followed; blue arrow, axon. Bar, 10 µm. (C) Staining for differentiated RGCs with Zn5 antibody in control retina at 48 hpf. (D) Zn5 staining in retinas treated with colcemid. (E) MT destabilization by overexpression (OE) of Stathmin 1 (hsp70:Stathmin1-mKate2) stalls RGC translocation. Heat shock applied at 30 hpf, imaging from 34 hpf. Graph shows all trajectories after RGC terminal division, the mean trajectory ± SD, and the mean trajectory in the wild-type situation. (F) Acetylated tubulin staining in progenitors. MTs were labeled by bactin:GFP-DCX. At 28 hpf, only apical primary cilia in progenitors are stained. Bar, 10 µm. (G) Acetylated tubulin staining in RGCs. All MTs were labeled by bactin:GFP-DCX. At 40 hpf, acetylated tubulin is seen in the apical process of RGCs (white arrows). White dots, translocating RGCs. (C, D, F, and G) Dashed lines represent apical and basal sides. Arrows, ectopic RGCs. Bar, 20 µm.