DOCK7/p116Rip signaling controls somal translocation through F-actin remodeling at the cell rear. (A) Neuroblasts dissociated from the V-SVZ of P1–3 mice were coelectroporated with one of the indicated constructs and a plasmid coexpressing Lifeact-EGFP, a marker for F-actin, and PACT-mKO1. Cells were reaggregated, embedded in Matrigel, and subjected to confocal live-cell imaging. Examples of time-lapse series showing F-actin remodeling during migration in neuroblasts transfected with indicated constructs. Signals of Lifeact-EGFP and PACT-mKO1 are shown in green and red, respectively. White dashed lines indicate advancement of the rear edge (RE) of each cell. White and yellow arrowheads indicate position of centrosome ahead of the nucleus and formation of F-actin condensation at the cell rear, respectively. Linescan profiles to the left of each image show the signal intensities of Lifeact-EGFP (green lines) and PACT-mKO1 (red lines) from the rear edge of the cell soma to the tip of the LP in the corresponding images. Representative images of a total of 5–12 independent experiments/condition are shown. (B) Enrichment of DOCK7 and p116Rip signals at the cell rear during somal translocation. Reaggregated neuroblasts isolated from V-SVZ tissue of P1–3 mice were embedded in Matrigel and allowed to migrate for 30 h before immunostaining for DOCK7 and p116Rip. Representative images of neuroblasts captured before (top two rows) and during somal translocation (bottom row) are shown. Enrichment of DOCK7 and p116Rip signals at the cell rear just before and during somal translocation is indicated by arrowheads. Bars, 10 µm.
