FIGURE 7:
Model: K-MT stability determines the relative importance of Eg5 in maintaining spindle bipolarity. Cells with long-lived K-MTs (top) do not continuously require Eg5, either because stable K-MTs do not pull on poles or because stable K-MTs are competent to withstand stronger pulling forces. Cells with short-lived K-MTs (bottom) continuously require Eg5, either because K-MT depolymerization pulls poles inward or because unstable K-MTs cannot withstand pulling forces from other sources.