Issues

Cells build bipolar spindles during mitosis and align their chromosomes (control) to help insure equal chromosome segregation to each daughter cell. When cells are treated with mitosis-specific Kinesin-5 inhibitors (4h in this example), bipolar spindles are inhibited and instead monopolar spindles form, with a radial array of microtubules surrounded by the chromosomes. These monopolar arrested cells then decide to progress down different pathways. We find profound variability in phenotypic responses and death in response to Kinesin-5 inhibitors, both within a given cell line and between cell lines. Green, microtubules; blue, DNA; red, centrin (centrioles). For details, see Orth et al., in this issue.