Isotropic incorporation of SPD-5 underlies centrosome assembly in C. elegans

Figure 1. SPD-5 incorporates throughout the volume of the PCM. (A) Schematic of assay to determine spatial dynamics of PCM assembly. Centrosomal GFP signal is bleached during centrosome maturation. Three possible outcomes for the pattern of new protein incorporation are shown. (B) Representative images of GFP::SPD-5 before and after bleaching/maturation. Post-bleach images scaled equivalently. (C,D) GFP::SPD-5 distribution before and after bleaching/maturation. Each profi le is an average of >9 centrosomes, normalized to the peak intensity of the pre-bleach signal (C) or the peak intensity at each time point (D). Error bars are the 90% confi dence interval for the mean. The slight spread of signal at later time points refl ects expansion of the PCM during centrosome maturation. (E) Fit of 65 s timepoint data to predicted fl uorescence distribution for each model. (F,G) Bleach marks created by partial photobleaching of GFP::SPD-5 in metaphase-arrested embryos are maintained over extended time frames. Schematics of potential outcomes (F) and representative images (G), scaled equivalently. Isotropic incorporation of SPD-5 underlies centrosome assembly in C. elegans