Fig. 4. Prolonged mislocalization of katanin from spindle poles results in a reduction of the -tubulin focus at prometaphase spindle poles. (A,B). CV-1 cells were transfected with plasmids encoding a GFP fusion to the C-terminal, con80, domain of p80 katanin, which causes endogenous p60 to mislocalize from spindle poles to the cytoplasm, or GFP alone. Cells were fixed and stained with an anti--tubulin monoclonal antibody either 20 hours (A) or 48 hours (B) post-transfection. The histogram shows the fraction of cells with -tubulin areas falling within each range of values shown. P indicates the significance of the difference between control (GFP alone) and experimental populations as determined with the Mann-Whitney test.