Figure 4.

RNAi knockdown of Cas impairs axon extension of cerebellar granule cells. (A–D) Confocal images of cerebellar granule cells transfected with Cas siRNA or LacZ siRNA. Cerebellar granule cells were cotransfected soon after cell dissociation by either Cas siRNA or LacZ siRNA with pCAG-EGFP. Cells were fixed and observed 48 or 72 h after the transfection. (A) LacZ siRNA 48 h; (B) Cas siRNA 48 h; (C) LacZ siRNA 72 h; (D) Cas siRNA 72 h. Scale bar, 200 μm. (E–G) Granule cells (stained by anti-Pax6 antibody; F) with multiple short axons observed in Cas siRNA transfection (E). (H) Percentage of cells with axons longer than 200 μm within each observation field 48 or 72 h after transfection. Data are presented as mean ± SEM. Values in the parentheses above the column indicate the number of observation fields from at least three independent experiments. ***p < 0.001, compared with the EGFP control (t test).