(A) 3D-SIM images show how during S-phase two adjacent Sas-4-GFP foci can be resolved at an individual centrosome (t = −20 s), and how the Sas-4-GFP fluorescence signal recovers only as a single foci after photobleaching (t = 120 s to t = 280 s). Time in seconds before and after photobleaching (t = 0 s) is shown in the top right of each panel. (B) Two-colour 3D-SIM images show how Sas-4-GFP fluorescence recovers relative to Asl-mCherry fluorescence (which surrounds the mother centriole). The Sas-4-GFP is shown in greyscale; insets (yellow dashed lines) display the overlay of Sas-4-GFP (green) and Asl-mCherry (red). Note how after photobleaching the Sas-4-GFP fluorescence recovers outside of the Asl-mCherry toroid. (C) Complementary images of a control centrosome adjacent to the one shown in (B) where the Sas-4-GFP signal was not photobleached. The t = 0 s panel is a widefield image (see ‘Materials and methods’). (D, E) Schematic (D) and box-plot (E) show how the average position of the post-bleached Sas-4-GFP signal is similar to the position of the daughter, but not the mother, centriole's prebleached Sas-4-GFP signal, relative to the Asl-mCherry signal. Boxes in E extend from the 25th-75th percentiles, whiskers extend from min to max values, lines in boxes are the median values, ‘+’ in boxes are the mean values; n = 25 centrosomes from 4 embryos. **** indicates where p < 0.0001; n.s. indicates where p = 0.09, and is therefore not significant. (F) 3D-SIM images show how Sas-4-mCherry (red) recovers relative to recovering Spd-2-GFP (green). An overlay of Sas-4-mCherry and Spd-2-GFP fluorescence is shown in the main panels; insets (yellow dashed lines) display the Sas-4-mCherry signal (greyscale). Note how after photobleaching the Sas-4-mCherry recovers outside of the hollow created by the recovering Spd-2-GFP (t = 300 s). (G) Complementary images of a control centrosome adjacent to the one in (F) where the Sas-4-mCherry and Spd-2-GFP signals were not photobleached. The t = 0 s image is a widefield image, as in (C).