Cells transfected with nuclear localization sequence (NLS) mutant ARX accumulate in early mitosis. (A) The percentage of un-transfected HEK293T cells undergoing various phases of mitosis at 24, 48 and 72 h in culture (time indicated on the X-axis) were determined from between 1200 and 4000 cells per sample, from at least three separate transfection reactions. (B) The percentage of mitotic cells at the DNA condensation stage (early phase, light grey), mitotic spindle stage (middle phase, dark grey) or undergoing anaphase/telophase/cytokinesis (late phase, black) are shown for cells expressing Myc-ARX-Wt or NLS mutations 48 h post-transfection. Full-length Myc-tagged ARX used in each group is indicated on the X-axis. Differences in the percentage of cells undergoing each phase of mitosis at different times post-transfection were compared using a two-way ANOVA. P < 0.05 versus ARX-Wt for * early phase, + middle phase and # late phase.