DOCK7 controls different cellular aspects of neuroblast migration via DHR2/Rac-dependent and R2-dependent pathways. (A) DOCK7 domain structure and deletion and point mutant constructs. ΔR2 comprises the DHR1 domain (amino acids 561–727) and TACC3-binding domain (amino acids 933–1,164). The asterisk indicates the DOCK7(V2022A) mutation. (B) Composite confocal images of forebrains of mice electroporated at P3 with plasmids expressing EGFP and Dock7#2 shRNA⁺DOCK7, Dock7#2 shRNA⁺DOCK7ΔDHR2, Dock7#2 shRNA⁺DOCK7V2022A, or Dock7#2 shRNA⁺DOCK7ΔR2 and sacrificed at P10, showing distribution of EGFP⁺ transfected neuroblasts along the V-SVZ–RMS–OB pathway. Slices were counterstained with DAPI. Dotted lines outline borders of sagittal slices. Bar, 500 µm. (C) Quantification of the distribution of EGFP⁺ transfected cells along the V-SVZ–RMS–OB pathway. n = 1,316–1,870 cells from at least three animals for each condition. (D) Quantification of the length of the LP of neuroblasts expressing indicated constructs. n = 91–680 cells from at least three animals for each condition. (E–H) P2–3 mouse pups were electroporated with a tdTomato-expressing plasmid together with one of the indicated constructs. Acute sagittal brain slices were prepared 5 d later and subjected to confocal live-cell imaging. Quantifications of the mean migrated distance (E), displacement (F), velocity (G), and number of branching events per h (H) for the tdTomato⁺ transfected neuroblasts. n = 42–61 cells from four to seven animals for each condition. Data are shown as means ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001; ns, P > 0.05 compared with scr#1; one-way ANOVA with Dunnett’s post hoc test.