Fig. 5. Analysis of lagging chromosome behavior during cell cleavage by time-lapse microscopy in a PtK1 cell released from a nocodazole-induced mitotic arrest. Numbers at the bottom right corner indicate the time in minutes from nocodazole washout. Two lagging chromosomes can be seen in the equatorial region of the dividing cell from cleavage furrow formation (60 minutes) until cytokinesis proceeds (85 minutes). In the last frame the position of the reforming membranes around the two daughter nuclei and the two micronuclei deriving from the two lagging chromosomes is highlighted by a white line for clarity. Bar, 5 µm.