Fig. 6.

 Metaphase analysis of MCF-7 cells. Clone C14 cells cultured with (off) or without (on) doxycycline were harvested for metaphase analysis 42 (A) and 69 (B) hours after BrdU. Two hundred metaphases were counted per group or experiment. Data represent the average number of metaphases observed from 4 experiments (42 hours) or 3 experiments (69 hours). Significant differences in the distribution of first, second, and third division metaphases were observed in C14-on cells compared with C14-off cells at 42 hours (P < 0.0001) and 69 hours (P < 0.001)