Fig. 3.

Two enhancers in pax3a intron 4 drive gene expression in the NPB and dorsal neural tube. (A) The Fugu pax3a locus is shown along with a Vista plot (Frazer et al., 2004; Mayor et al., 2000) of sequence identity between Fugu and zebrafish, Fugu and human, and Fugu pax3a and its paralog pax3b. Enhancer regions are shown in red and pax3a exons are shown in yellow. (B-O) GFP expression driven by IR1 (B-H) and IR2 (I-O) is shown as detected by in situ hybridization for embryos at 12 hpf (B-G,I-N) and by fluorescence at 24 hpf (H,O). Optical cross-sections through the trunk region confirm that IR1 and IR2 drive gene expression in the ectoderm (E,L) and double in situ hybridization for GFP (brown) and pax3a (purple) demonstrate that pax3a expression overlaps with the activity of IR1 and IR2 (F,G,M,N). G and N are higher magnification views of the areas outlined in F,M, respectively. B,H,I,O are lateral views; C,J are dorsal trunk views; D,K are posterior dorsal views.