Fig. 4

Impaired migration and nucleus-centrosome coupling in neurons expressing BicD2 K775X. a Organotypic brain slice cultures from brains electroporated with BicD2 WT or K775X at E14.5 and imaged 2.5 days later. Time lapse images, taken at 10-min interval of a representative cell expressing BicD2 WT, shows continuous migration toward the CP (upper panel). The BicD2 K775X-expressing cell stayed stationary and failed to migrate forward (lower panel). b Distance-time graphs of representative cells expressing BicD2 WT (upper panel) showed classic migration pattern, while cells expressing BicD2 K775X (lower panel) showed severe impairment in migration ability. c Bar graph with individual data points shows the migration rate of cells expressing BicD2 WT or K775X. Expression of BicD2 K775X a dramatic decrease in migration rate. Error bars represent SEM. ***p < 0.001. Student’s t test. d Images of the centrosome and nucleus of a migrating neuron electroporated with BicD2 WT or K775X cDNA along with GFP (green) and Centrin II-DsRed (red) at E14.5. Cells were stained with DAPI (blue) to label the nuclei. The centrosomes (arrowhead) in most BicD2 WT-expressing cells were found in the perinuclear area (left panel). In contrast, in cells expressing BicD2 K775X, the centrosomes were often found further along the leading process at a longer distance from the nucleus (right panel). e Bar graph with individual data points of the average distance between the nucleus and centrosome in cells expressing GFP, BicD2 WT, and BicD2 K775X (n = 3 pregnant females in each condition). Error bars represent SEM. ***P < 0.001, ****P < 0.0001. ANOVA. Post hoc: Bonferroni test. f Time lapse images, taken at 10-min interval, of representative cells expressing BicD2 WT or K775X along with Centrin II-DsRed (red) and GFP (green) simultaneously. The cell expressing BicD2 WT showed a classic “two stroke” migration pattern. In contrast, the cell expressing BicD2 K775X remained stationary after the centrosome migrated into the leading process