a, Measured attachment lifetimes for wild-type (WTasyn) and dad1-1 particles. Tension initially prolongs and then shortens lifetimes for wild-type attachments. Dotted curve shows prediction of the two-state model (see text). b, Schematic of two-state model with detachment during assembly and disassembly (rates k3 and k4, respectively), and interconversion between states (k1 and k2). c - e, Measured rates and exponential fits for detachment during assembly (c, red), detachment during disassembly (c, blue), catastrophe (d, red), rescue (d, blue), growth (e, red) and shortening (e, blue). Errors represent (a-d) counting uncertainty (N = 24-65) and (e) s.e.m. (N = 78-360).