Fig. 3. Anterior retention of PLK-1. (A,C) Confocal images of GFP-PLK-1 embryos before photobleaching (first panels), immediately after photobleaching the anterior half (A, second panel) or the posterior half (C, second panel) and three time intervals afterwards (third to fifth panels). Time elapsed is indicated in seconds with 0 corresponding to the end of photobleaching. (B,D) GFP-PLK-1 relative intensity ±s.e.m. plotted as a function of time, both for anterior (B, n=5) and posterior (D, n=7) photobleaching. Five images before photobleaching and 20 images afterwards were captured every 10 seconds, except for the images captured immediately after photobleaching, which were captured 12 seconds after the previous one. GFP-PLK-1 movement from the posterior to the anterior rapidly results in uniform GFP-PLK-1 distribution (B), whereas movement from the anterior to the posterior does not, leaving GFP-PLK-1 distribution asymmetric (D).