Figure 7.

Model of the delaying effect of strong SMF on early development. (a) Dissociative tubulin dimers are randomly distributed in cytoplasm in control condition. (b) Tubulin dimers tend to orient with α–β axis parallel to SMF direction, altering the polymerization rate at astral microtubule ends. The thickest arrow means the largest polymerization rate. (c) Microtubules are rotated under magnetic torque from SMF. The thickest arrow means the largest rotating speed. (d) Microtubules bend to the direction of SMF. The largest deflection happens at the microtubule ends. (e,f) Schematic diagram shows the positioning and orienting of spindle by microtubules (e) without or (f) with an external SMF. (g) Computational simulations of the positioning process of spindle with and without SMF. t* = t/τ_d, where τ_d is the relaxation time for positioning process without SMF [25]. (h) Computational simulations of the orientation process of spindle with and without SMF. t* = t/τ_α, where τ_α is the relaxation time for orientation process without SMF [25].