Time-lapse imaging of insulin:GFP transgenic embryos shows cell migration defects in Fz-2 morphants. (A, C-H) Uninjected insulin:GFP transgenic embryo, (B, I-N) fz-2 MO-injected insulin:GFP transgenic embryo. All panels are dorsal views and anterior is to the left. Scale bar represents 100 μm. (A) Uninjected transgenic embryo, 24 hpf. (B) Fz-2 MO-injected transgenic embryo, 24 hpf. (C) At the 14-somite stage, bilateral patches of GFP-positive cells are visible in uninjected embryo. (D) At the 15–16 somite stage, GFP-positive cells have started proliferating. (E-G) At the 17 somite to 24 hpf stages, GFP-positive cells are aligned in bilateral rows of cells and undergo a medial and posterior migration. (H) At 24 hpf, all GFP-positive cells have merged to form one islet. (I) At the 14-somite stage, bilateral patches of GFP expression are apparent in fz-2 MO-injected embryos similar to uninjected embryos. (J-M) GFP-positive cells migrate in random directions in fz-2 morphant embryos. (N) At 24 hpf, GFP-positive cells have still not merged. (O) Trajectory of GFP-positive cells in uninjected insulin:GFP embryo. Notice that cells are uniformly moving posteriorly. (P) Trajectory of GFP-positive cells in fz-2 MO-injected insulin:GFP embryo. Notice cells are moving in random directions. A: anterior, P: posterior, T: time, L: left, R: right, O: origin.