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Microtubule depolymerization at kinetochores restricts anaphase spindle elongation
Biorxiv : the Preprint Server for Biology
|September 11, 2024
Summary
Central spindle sliding, not kinetochore microtubule depolymerization, drives chromosome separation during anaphase. This study reveals a direct link between the central spindle and chromosomes, challenging previous models of cell division.
Area of Science:
- Cell Biology
- Molecular Biology
- Genetics
Background:
- Anaphase chromosome segregation relies on spindle microtubule forces.
- Current models propose forces are mediated via spindle poles, with central spindle sliding pushing poles apart and kinetochore microtubule (kMT) depolymerization pulling chromosomes poleward.
Purpose of the Study:
- To investigate the direct linkage between the central spindle and chromosomes during anaphase.
- To re-evaluate the forces driving chromosome segregation and spindle elongation.
Main Methods:
- Analysis of chromosome movement in monopolar spindles.
- Experimental manipulation of central spindle sliding in bipolar spindles.
- Varying the rate of kinetochore microtubule depolymerization.
Main Results:
- Chromosomes in monopolar spindles moved away from the pole, supporting central spindle sliding forces.
- Suppression of central spindle sliding constrained kMT depolymerization, indicating a direct kinetochore-central spindle linkage.
- Increased kMT depolymerization slowed pole separation without affecting chromosome separation velocity.
Conclusions:
- Central spindle sliding is the primary driver of anaphase chromosome separation.
- Kinetochore microtubule depolymerization acts as a limiting factor for spindle elongation, not a primary driver of chromosome movement.
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