Fig. 4. Modulation of MAP4-mediated mitotic arrest and monoastral spindles. The coexpressing cell populations described in Fig. 3 (20 hours of induced expression) were stained with propidium iodide followed by analysis of DNA content by flow cytometry (upper panels). The inserts in two of the upper panels show G2/M block of cells after 24 hours in the presence of paclitaxel (1 µM). Mitotic figures were analyzed with respect to bipolar, small or intermediate-to-large monoastral spindles (see lower panel; bar, 6 µm) by inspection of cells double stained for DNA and MTs. The distribution of different types of mitotic cells represents the mean of duplicate determinations, using independent cell preparations, from one transfection experiment (n=450 cells). All data in this figure are derived from the same transfected cell populations but are representative of at least three independent transfection experiments.