Fig. 5. Microtubules determine growth site position, but are not required for establishment of polarized growth. (A) Brightfield images of cdc25-22-blocked (3 hours prior to treatment) cells treated with MBC or DMSO. (B) Branch position at different MBC concentrations, measured as relative distance from the middle of the cell. Between 50 and 100 cells were scored for each MBC concentration. (C) Average microtubule length (bars) and branching efficiency (percentages) at different MBC concentrations. 25-35 cells were scored for each MBC concentration. Bar, 5 µm.