Effects of ZM treatment during the interphase. Cells were loaded with GST-NLS-GFP and Fab311-555 and treated with ZM for ∼20 min. (A) Response of Fab311 to ZM addition and removal in hTERT-RPE1. See Video 10. (B) An hTERT-RPE1 cell that exhibited chromosome missegregation after transient exposure to ZM. (C) Effects of transient exposure to ZM on the formation of Fab311 foci and chromosome segregation. ^aLoaded cells were incubated in the absence (−) or presence (+) of ZM. ^bThe period when Fab311 foci appeared before the nuclear membrane broke down (judged by the release of GST-NLS-GFP from the nucleus into the cytoplasm). Mean ± SD, range, and number of cells analyzed (n) are indicated. ^cThe percentage of cells showing aberrant chromosome segregation. Bars, 5 µm.