Figure 2.
(A–F) Selected video images from an untreated PtK1 cell with independent bipolar and monopolar spindles. In this cell the bipolar spindle entered anaphase (C) 24 min after its last monooriented chromosome initiated congression (arrow in A), and in the presence of numerous monooriented chromosomes on the monopolar spindle. Arrows in D and E indicate unattached anaphasic chromatids on the monopolar spindle. Note that a cleavage furrow is initiated between the poles of the bipolar spindle, and also between the poles of the bipolar and monopolar spindles where no chromosomes were present (arrowheads in F). (Bar = 10 μm.)