Figure 3.

Catastrophic Collisions between Cortical Microtubules after Steep-Angle Encounters.

The outcome of steep-angle encounters between cortical microtubules in MBD-DsRed–expressing cells is shown. The microtubule of interest is marked by an asterisk, and the small arrows denote the onset of microtubule polymerization or depolymerization. The large open arrows show the transverse direction with respect to the cell elongation axis. The numbers denote time in seconds.

(A) A growing cortical microtubule has a steep-angle (73°) encounter at 45 s (c) with a preexisting microtubule and depolymerizes after ∼20 s of contact. The microtubule then undergoes a rescue event and has a second steep-angle (73°) encounter (at 140 s), followed rapidly by depolymerization.

(B) A growing cortical microtubule has a steep-angle (75°) encounter with a preexisting microtubule, which it crosses over (x), and continues growing. This microtubule then has a second steep-angle (70°) encounter at 50 s (c), which is followed rapidly by a catastrophe. Scale bars = 2 μm.