Figure 2.

Geometric diagram of the MA relative to the cell cortex during anaphase. From confocal images of fixed cells stained for microtubules, we measured the distances of the polar-directed (a) and equatorially directed (b) astral MTs to the cell cortex at the time of anaphase onset, the spindle length at anaphase onset (c), and the spindle length at the time of furrow initiation (d). These measurements were used in conjunction with our analysis of anaphase astral MT growth rates to predict the time of contact between astral MTs and the polar versus equatorial cortex, relative to the time of furrow ingression.