Spindle microtubule re-growth is delayed in NuMA-depleted cells. (A) Microtubules were depolymerised on ice for 1.5 hours, and re-polymerised at 37°C. At the indicated time points, cells were fixed and subjected to immunofluorescence of NuMA (red), tubulin (green), and staining of DNA (blue). Spindles in NuMA-depleted cells have a lower microtubule density and are less 'compact'. Bar, 5 μm. (B) Graph, indicating the percentage of regular, compact spindles at the indicated time points of microtubule re-growth (data from four independent experiments; between 50 and 100 cells were counted for each point).