Extended Data Fig. 4: Role of stable microtubules in PR migration.
From: Neuronal migration prevents spatial competition in retinal morphogenesis
a, Correlation between PR and sister RGC positions relative to the apical surface (0 μm). Each dot represents an individual time point from 20 pairs of PR–RGC cells (450 time points, N = 7 embryos). b, Bidirectional migration of sister PRs after Ath5 morpholino-mediated knockdown. Tg(ath5:gap-RFP) (grey) labels early neurogenic progenitors. Yellow and blue dots mark sister PRs. c, Distribution of stable microtubules (MTs) in apically migrating PRs at 42 hpf. Tg(crx:gap-CFP) (grey) labels PRs; acetylated tubulin labels stable MTs, lookup table shows minimum and maximum signal values. Dashed white box indicates areas shown in c’ and c”. Arrowheads mark basal processes of PRs. d, Effect of colcemid-induced MT depolymerization on PR basal migration. Embryos were treated with 100 µM of colcemid (DMSO for control) from 30 hpf for 8 h. Tg(crx:gap-CFP) labels PRs, lookup table shows minimum and maximum signal values; phalloidin (grey) labels F-actin. Arrowheads mark PRs. e,f, Effect of mosaic overexpression of stathmin on PR migration. e, ath5:GFP-CAAX (magenta) labels early neurogenic progenitors; hsp70:Stathmin1-mKate2 (yellow). White dots mark PR. f, Trajectories of PRs upon stathmin overexpression (n = 8 cells, N = 3 embryos) relative to the apical surface (0 μm) and typically behaving wild-type (WT) cell from Extended Data Fig. 2a for comparison. g,h, Effect of tissue-wide stathmin-induced MT depolymerization on PR apical migration. Heat shock induction of stathmin expression at 42 hpf. Tg(crx:gap-CFP) (grey) labels PRs. For prevalence of phenotype, see Extended Data Fig. 5e. Scale bars: 5 μm (e), 10 μm (b), 20 μm (c,d,g,h). In b,e,g–h, time is displayed in hours:minutes.
