Figure 4.

Depletion of Neurl4 results in the formation of aberrant CP110-positive assemblies and mitotic defects. U2OS cells were transfected with a nonspecific (NS) or two different siRNAs targeting Neurl4. The percentage of cells with >4 CP110 foci or centrin foci (A) or γ-tubulin foci (B) is analysed. In C, U2OS cells were transfected by indicated siRNA and treated with 10 mM nocodazole to induce microtubule depolymerization. (D) A set of representative electron microscopic images of U2OS cells treated with Neurl4 siRNA. A series of adjacent sections are shown. White arrows point to the extra electron-dense material observed after Neurl4 depletion. Black arrowheads point to normal centrioles. (E,F) U2OS were transfected with control or Neurl4 siRNA for 72 h. Mitotic cells were scored and representative pictures were shown. At least 100 cells for each siRNA transfection were scored for each experiment. Individual channels in E are also shown in supplementary Fig S7A online. Error bars in graphs represent standard error of the mean (s.e.m.). ^*P<0.05; ^**P<0.01. Scale bar, 10 μm. DAPI, 4,6-diamidino-2-phenylindole; Neurl4, Neuralized homologue 4; NS, nonspecific; siRNA, small interfering RNA.