Figure 5

Functional analysis of shha and shhb ar-C conserved motifs. This analysis reveals the basis for divergence in tissue specificity. Panels a to e show a transgenic analysis of shha ar-C motifs by site specific mutations. Embryos injected with the corresponding constructs are shown at 24 hours post-fertilization (hpf) lateral view onto the trunk at the level of the midline. Shown are embryos injected with gfp-reporter constructs containing (a) wild-type zebrafish shha ar-C, (b) ar-C with mutated C1 region, (c) mutated C2, (d) mutated C3, (e) mutated C4, and (f) C4 replaced with medaka C4 (C4m). Panels g to k show a transgenic analysis of shhb ar-C motifs. Shown are embryos injected with gfp-reporter constructs containing (g) wild-type zebrafish shhb ar-C, (h) ar-C with mutated C1 and (i) mutated C3, and with (j) exchange of shhb sequence with the zebrafish shha C2 and with (k) the zebrafish shha C4. Stacked-column graphs show the quantification of the gfp expression, as described in Figure 3. Arrows and arrowheads point to floor plate and notochord cells, respectively. Lines on the left side indicate the level of the floor plate and notochord on the images. ect, ectopic; fp, floor plate; nt, notochord.