Loss of chromokinesins causes misorientation and entanglement of chromosome arms. Selected frames from 4D fluorescence microscopy time-lapse sequence of HeLa H2B-GFP cells 30 h after hKID/KIF4A siRNA transfection. 30 z-sections were taken every 15 s (for a total time of 30 min), processed by deconvolution, and carefully analyzed in 3D over time using Imaris to distinguish different chromosomes. The first frame shows a cell with unaligned chromosomes stuck at the poles. The white box indicates the area of the inset with three chromosomes, labeled in blue, red, and green. The following frames show that these chromosomes remain stuck although their arms get extended as if pulled from the opposite spindle pole. Only after a long delay, the red chromosome becomes free and congresses to the metaphase plate. Time is min:s. Bar, 5 µm.