Fig. 3. Soluble SDF1 decreases the average and maximum velocity of PGCs. (A) An E9.5 control slice. (B) An E9.5 slice in the presence of 1.6 µg/ml SDF1. (C,D) Slices shown in A,B after 7.5 hours of culture, respectively. (E,F) Trajectories of cells in control (E) and SDF1-treated (F) slices. Green outlines represent starting positions of cells and red outlines indicate ending positions of cells. Arrow indicates the position of the gut. Black lines follow trajectories of five selected cells in the experimental and control slices. (G) Summary of PGC velocity data from five control and four SDF1-treated slices. Error bars show standard deviation. Scale bar: 55 µm (A-F).