Behavior of Mad2 and BubR1 during MUG. (A) Cells in MUG were treated with nocodazole to generate unattached kinetochores or were left untreated. Differential interference contrast and fluorescence images of cells stained for DNA, kinetochores, and Mad2. The histogram presents the integrated intensity of Mad2 normalized to nocodazole-treated cells. (B) The distribution of BubR1 during normal mitosis and MUG. The histogram presents the integrated intensity of BubR1 on control and MUG kinetochores normalized to prometaphase. Error bars indicate SEM.