Figure 6.

Depletion of Aurora-A by siRNA impairs neuronal migration. a, Granular neurons were transfected with siRNA against Aurora-A. Western blotting was performed 48 h after start of culture of the siRNA. Aurora-A was clearly reduced after siRNA, whereas NDEL1 displayed similar expression levels. Phosphorylated NDEL1 was decreased after knockdown of Aurora-A. Relative intensities of the bands of Western blotting is shown at the bottom. Intensities were normalized against β-actin. Statistical examination was performed by unpaired Student's t test, with **p < 0.01 (bottom panel). b, c, Immunocytochemistry revealed that the Aurora-A signal (b) was nearly invisible. NDEL1 expression (c) was unchanged, whereas phosphorylated NDEL1 was decreased after treatment of siRNA to knockdown Aurora-A. The white dotted lines indicate the outline of granular neurons. d, Rescue experiments after siRNA treatment to knockdown Aurora-A using control GFP, GFP-Ndel1 (S251A), or GFP-Ndel1 (S251E) transfections. GFP images are shown in the top panels. Hoechst images are shown in the bottom panels. Expression of GFP-Ndel1 (S251A) had no effect on reduced migration after siRNA knockdown of Aurora-A, whereas expression of GFP-Ndel1 (S251E) significantly improved this reduced migration. e, The migration distance of each neuron 48 h after the start of culture was binned. n is the number of neurons measured for each examination. Expression of GFP-Ndel1 (S251E) significantly improved migration, which was characterized by a rightward shift. f, Mean length of neurites (open bar) and nuclear position (solid bar) from the edge of central aggregation. Statistical examination was performed for nuclear migration by an ANOVA followed by t test with correction: **p < 0.01.