Lagging chromosomes are infrequently observed in KIF18A KO late anaphase cells. (A) Representative late anaphase RPE1 cells treated with nocodazole washout or containing KIF18A KO mutations. Missegregating chromosomes in the midzone were quantified in late anaphase by eye and included both lagging chromosomes (as determined with DNA staining, white arrowhead) and chromatin bridges (yellow arrowhead). (B) Percentage of late anaphase cells containing one or more lagging chromosomes or chromatin bridges from the indicated experimental conditions. Lagging chromosomes were observed in 44% (52 of 118) of nocodazole washout–treated RPE1 cells and in 9% (4 of 43) of KIF18A KO cells. *, P < 0.001. Data are from one experiment. Indicated P value was calculated by χ2 analysis. (C) Plot of SDs of chromosome distance measurements in cells with chromosomes meeting the definition of “lagging” (see Fig. 7 B). Measurements in late anaphase RPE1 cells treated with nocodazole washout or containing KIF18A KO mutations. P = 0.14, ns. Noc., nocodazole.
