Question

What drives the construction of bipolar spindles?

Answer 1

Construction of bipolar spindles:

1. The construction of a bipolar spindle in eukaryotes is largely based on the observation that spindle elements organize on their own.
2. Plus-end-directed kinesins of the kinesin-5 family as the key players in driving spindle bipolarity.
3. Kinesin-5 motors are tetrameric kinesins with two motor domains on each side of the tetramer.
4. It allows them to simultaneously bind, walking along two antiparallel MTs, thereby sliding them apart.
5. Such antiparallel sliding activity is thought to generate an outward sliding force within the spindle that pushes centrosomes apart, thereby promoting spindle bipolarity.
6. The minus ends are cross-linked by microtubule-associated proteins for the formation of a pair of spindle poles.
7. As the microtubules grow, a few plus ends get attached to kinetochores.
8. Then it connects chromatids to the poles pulling them to initiate anaphase.