Figure 10.

Phosphorylation of fascin on Ser39 regulates neuroblast directionality ex vivo. P2 mice were electroporated in the lateral ventricle with pGFPC2 (empty vector), pGFPC2-S39D or -S39A fascin, and pCX-EGFP in a 3:1 ratio. Acute brain slices were prepared 5 d after electroporation. A, Projections of spinning disk confocal z-stacks (corresponding to the same cell imaged at three different time points) showing representative migrating neuroblasts expressing GFP, S39A fascin, or S39D fascin. Cells expressing S39A (middle row) or S39D (bottom row) fascin branched more frequently compared with GFP-expressing cells (top row). B, Detailed analysis of spinning disk movies shows an increase in the number of branching events per hour for neuroblasts expressing S39A or S39D fascin compared with control cells (mean ± SEM; n = 80 cells from eight brain slices for GFP; and n = 60 cells from six brain slices for S39A and S39D; ***p < 0.001). C, The migratory index (net distance divided by total distance) is significantly decreased by the expression of either S39A or S39D fascin (mean ± SEM; n = 8 slices for control; n = 6 slices each for S39A and S39D; *p < 0.05). Scale bar, 30 μm.