Cell biologists have long thought that cytokinesis, the final step of cell division in which the cytoplasm and its contents are split, is necessary for the proper assortment of chromosomes. Disrupt this process, the prevailing wisdom held, and aneuploidy will result, with cancerous implications. But a team led byMark Burkard at the University of Wisconsin–Madison has discovered a new type of cell division, dubbed ‘klerokinesis’, that protects cells from failed cytokinesis.
Using live-cell imaging, the researchers watched retinal pigment epithelial cells for five days after they had chemically inhibited cytokinesis. Reporting today at the American Society for Cell Biology’s annual meeting in San Francisco, they showed that many cells managed to split into two during the first growth phase of the next cell cycle—not during mitosis—allowing each to recover a normal chromosome set. Burkard says that therapeutic strategies that boost this type of nonmitotic cell fission could prevent cancer in people at high risk of developing tumors marked by abnormal chromosomal counts.