Spindle oscillations differ between C. elegans and C. briggsae embryos. (A and B) Centrosome displacement on the A/P (y axis on the left) and transverse axes (y axis on the right) relative to anaphase onset (t = 0 s) for one representative embryo per species. The position of the posterior centrosome on the A/P axis is represented by a black curve, while its position on the transverse axis is shown in red. Transverse movements of the anterior centrosome are shown in green. (C) The onset and end of posterior centrosome oscillations were measured manually from graphs of transverse oscillations (see A and B). Oscillation duration for each embryo is represented relative to the time at oscillation onset (in seconds from anaphase onset). (D) The position of the posterior centrosome in percentage of cell length at the beginning of oscillation is plotted versus the time at oscillation (in seconds from anaphase onset).