The roughly spherical object present in the field of view at the beginning of the digital video is a cell attempting to undergo division. The process does not appear to run smoothly, however, for the cell. Notice, the MDOK cell retains the pre-mitotic spherical form for a relatively considerable amount of time. Then, it begins to undergo various contortions and appears to try to split its contents into two daughter cells. The MDOK cell is unable to complete cytokinesis, however, and reassumes the geometry of a single sphere before eventually settling on the surface of the imaging chamber. As the epithelial cell flattens on the substratum it becomes clear that instead of producing daughter cells, the activity of the cell resulted in creating a single multinucleated cell.
Several cytoplasmic fragments are located on the substratum to the right of the cell attempting to divide as the video initiates. The fragments were presumably produced when an actively migrating cell failed to release all of its adhesions causing it to leave bits of cellular material in the wake of its path, or when a dead cell was broken apart. Sometimes such small bits of material are carried away from the surface of the imaging chamber by currents in the culture medium. These particular fragments, however, appear fixed in position until many of them are swept up by the ruffling lamellipodia of nearby epithelial cells and incorporated into their own contents.
In addition to the previously discussed cell, several other MDOK cells appear to have difficulty completing mitosis. A cell with an extremely large nucleus in the upper left-hand corner of the field of view contorts wildly after it retracts most of its surface extensions to form an approximately spherical form. Again, cytokinesis does not appear to be completed and the process results in another multinucleated cell. Near the end of the time-lapse sequence, an epithelial cell along the upper edge of the field of view seems to struggle with the division process as well, but its fate is unclear as the video ends.
