Flux occurs even in monopolar spindles, which lack sliding forces.
Flux is the poleward translocation of spindle microtubules relative to the poles that often helps chromosomes reach separate poles. Flux can be achieved by pushing microtubules outward from the center, by pulling them in from their ends, or by a combination of the two.
In fly S2 cells and in frog extracts, Eg5 is found at the central spindle, where antiparallel microtubules overlap. By cross-linking these microtubules and sliding them toward the poles, Eg5 has been proposed to create flux.
As Eg5 pushes from the middle, kinesin 13 lops off tubulin subunits at the poles. Kinesin 13 inhibition lengthens spindles but does not prevent the sliding component of flux, suggesting that...
