Mitosis without wind

The relatively minor effects of interfering with a kinesin that mediates polar ejection forces suggests that kinetochores may be smarter than once thought.This conclusion comes from a report on page 1135 from Levesque and Compton. Their antibody experiments target a human kinesin motor called Kid that sticks to chromosome arms and is thought to mediate chromosome movement out along spindle microtubules. This polar ejection force has been proposed as a mechanism for pushing chromosomes away from spindle poles and thus aligning chromosomes on the metaphase plate.

The importance of Kid and the polar ejection force has been shown in fly germ cells mutant for the Nod kinesin, and in frog extracts, where depletion of Kid resulted in widespread wandering of chromosomes away from in vitro assembled metaphase plates. Levesque and Compton set out to...