Identification of mitotic H2B S6ph functions. (A) Prophase LLC-PK cells were injected with anti-H2B S6ph antibodies or rabbit IgG at the onset of mitosis and further traced by live cell imaging. Pictures show representative phenotypes after injection of rabbit IgG (top) or anti-H2B S6ph antibodies (bottom). Time points after injection of antibodies are indicated (min:s), areas of microinjections are marked with asterisks (*) and the position of the cleavage furrows by arrows. Bars, 10 µm. (B) Prophase LLC-PK cells were microinjected with PBS (n = 5), rabbit IgG (n = 8), or anti-H2B S6ph antibodies (n = 6). Movement rates (changes in µm/min) during anaphase are displayed. Time lapse images after microinjection of antibody or PBS were collected at 1-min intervals. Chromosome movement rates just before and during anaphase were quantified by measuring the change in distance between leading edges of the chromosome masses as they moved poleward. Each line represents the chromosome movement rates obtained from individual cells. Each cell’s data were aligned so that minute “1” represents the first minute where anaphase movements were observed. (C) Chromosome movement rates during anaphase (t = 1 min through t = 11 min) were compared between samples from individual anti-H2B S6ph injections. Samples were labeled and arranged according to their phenotypes (ranging from slight to severe chromosome segregation defects). Lines show mean movement rates and standard deviations between the time points. (D) Average chromosome movement rates for every time point during anaphase (t = 1 min through t = 11 min) were calculated and compared between the three conditions using GraphPad Prism. Lines show mean movement rates and standard deviations between the time points. The asterisk (*) indicates a significant P value < 0.04; ns = not significant (paired t test).