FIGURE 7:

Persistent caspase activity leads to granddaughter cell arrest. (A) Asynchronous cultures were treated with nocodazole for 6 h and immediately after drug washout treated with the p38 inhibitor SB 203580 for 8 h. All daughters born of mothers spending >1.5 h in prometaphase progressed through interphase and divided again. However, all granddaughters still in the fields of view arrested. For the same preparation daughters born of mothers spending <1.5 h in prometaphase all granddaughters proliferated (not diagrammed). (B) The same experiment except that the pan-caspase inhibitor z-VAD(Ome)-fmk was included during the 8 h SB 203580 treatment. All daughter cells born of mothers spending >1.5 h in prometaphase progressed through interphase and divided again, and 87% of the granddaughters proliferated. (C) For the same preparation, daughters born of mothers spending <1.5 h in prometaphase all granddaughters proliferated.