- Cells divide by segregating chromosomes via the spindle apparatus, a microtubule structure that pulls chromosomes apart.
- Researchers used microneedles to physically manipulate mammalian spindles, revealing a self-repair mechanism under force.
- Spindle fibers break in the middle when pulled, but stabilize rather than unravel, akin to a melted rope end.
- Force application triggers the replacement of unstable microtubule components with more stable ones, reinforcing the spindle.