GPR sets the spatial switch for oscillations. (A–F) Plots represent the mean cortical intensity of GPR (from 0 to 1) from n anaphase embryos stained with GPR (red), tubulin (green), and DNA (blue) and normalized to the maximum intensity. Values have been projected onto the A/P axis, from the anterior pole (0%) to the posterior pole (100%). The asterisks represent the edge of the posterior plateau. One representative embryo is shown on the left. Anterior is to the left. Arrows show the edge of the GPR posterior domain. Bars, 10 µm. (G–I) Histograms from analysis of oscillation curves. Ce-gpr-(lf) corresponds to gpr-1(ok2126) or gpr-2(ok1179) mutant embryos. Statistical differences are shown with white, gray, or black stars for comparison to wild-type C. elegans, wild-type C. briggsae, or Cbr-Gβ(RNAi), respectively (for P < 0.05). Error bars represent standard deviation. The time at posterior centrosome oscillation onset relative to anaphase onset is shown in G, the position of the posterior centrosome at oscillation onset is shown in H, and the maximum amplitude of oscillations is shown in I. (J) Position of the edge of the GPR plateau on the A/P axis was measured from individual graphs of GPR cortical intensities in A–D. Mean values are shown, error bars indicate standard deviation.