Fig. 4

Changes in developmental expression pattern as a result of promoter deletions. Transgene expression in stable GFP reporter fish carrying the Fugu 3.6-kb gap43 promoter (A-D), or promoter deletions: ΔA (E-H), ΔB (I-L), ΔAB (M-P), and ΔABC (Q-T). Images of 48-hpf embryos captured on the fluorescent stereoscope (A, A inset, E, I, M, Q) show that promoter deletions result in overall lower levels of GFP expression (scale bar in Q = 500 μm). The image in (A) was taken at 1/3 the exposure time, while the overexposed image in the inset was taken at the same exposure time as E, I, M, Q. Higher magnification views of the embryos (B-D, F-H, J-L, N-P, R-T; scale bar in T = 100 μm). Dorsal view of hindbrain at 24 hpf (B, F, J, N, R). Lateral view of brain at 48 hpf (C, G, K, O, S). Ventral view of head at 48 hpf (D, H, L, P, T). cb, cerebellum; hb, hindbrain; ob, olfactory bulb; oc, optic chiasm; oe, olfactory epithelium; ot, optic tectum; rgc, retinal ganglion cells.