Fig. 1.

Location of severing determines its effect on alignment. (A) Angle-dependent collision outcomes. Bundling (“B”) occurs for collision angles $\theta <{\theta }^{\ast }=40°$; for larger angles, induced catastrophes (“C”) occur with probability $P_{cat}$, and, otherwise, MTs cross over (“X”). (B–D) Alignment ($S_2$) as a function of $G_c$. (B) Random severing (rates per micrometer per second as indicated). (C and D) Crossover severing (rates per crossover per second as indicated) for (C) aselective (either side of crossover) and (D) crossing only. In B–D, error bars show the SEM, with n = 100 independent simulations per data point. (E) Representative snapshots (SI Appendix, Unbiased Selection of Snapshots) for various induced catastrophe rates $r_c$ and severing rates ($r_s$ and $r_x$) at T = 30 h. MTs are colored according to their orientation, to enhance the visibility of domains with different orientations.