Supplemental Material

This article contains the following supporting material:

• Movie 1 - Control.
  HeLa cells were transfected with control (empty pSUPER) plasmid, and those directing expression of mCherry-tubulin and histone H2B-GFP. Time-lapse recordings of live cell images were obtained three days later, as described under Materials and Methods.

• Movie 2 - Early cytokinesis failure.
  Cells were treated as in movie #1 except that the pSUPER vector contained an insert for knockdown of Arl3. Note the failure in cytokinesis occurs very early in the process.

• Movie 3 - Late cytokinesis failure.
  Cells were treated as in movie #2, but in this case the failure in cytokinesis occurs after formation of the midbody so may also be described as a failure in abscission.