Chromosome-segregation defects and nonmodal karyotypes in HyperD-ALL blasts. (A) Representative DNA (blue)-Kinetochore (purple)-spindle (green and red) IF staining identifying lagging and bridge chromosomes. Yellow arrowheads depict the indicated chromosome-segregation defect. (B) Frequency of blebbistatin-treated mitotic PDX-expanded primary blasts with lagging and bridge chromosomes; n = 151 mitosis from 3 non-HyperD and 96 mitosis from 3 HyperD-ALLs. (C) Comparison of modal karyotypes from 50 metaphases from primary HyperD (n = 6) and non-HyperD (n = 6) B-ALL samples. (D) Frequency of cells showing modal karyotype. (E-F) FISH analysis using DNA probes for chromosomes 12 (green) and 21 (red) of 200 interphase nuclei from n = 3 non-HyperD and 4 HyperD-ALL primary samples. (E) Frequency of cells representing the modal clone vs minor clones. (F) Representative FISH analysis for a primary non-HyperD and a HyperD-ALL. Graphs represent the mean and error bars represent the standard error of the mean. *P < .05, **P < .01; ***P < .0001 (2-way ANOVA). Scale bars, 10 µm.