Fig. 1

Fig. 1

A conserved 190 bp enhancer upstream of Bmp6 drives gene expression in several domains. (A) The 52 region of stickleback Bmp6 from the UCSC genome browser (http://genome.ucsc.edu/). The region of genomic DNA used in the 2.8 kb enhancer construct (see Fig. S3) is shown in green, conserved sequences (CS) 1–3 are shown in purple, and the subcloned 190 bp enhancer is shown in yellow. The first exon and part of the first intron of Bmp6 are shown in thick and thin black lines, respectively (bottom). Conservation peaks and alignments (dark blue and gray) are shown from the 8-Species MultiZ track. (B) Zoom in on the middle of CS1, approximately 2.5 kb upstream of the predicted Bmp6 transcription start site. The 190 bp enhancer, the 72 bp minimal enhancer (see Fig. S6), and a predicted Smad3 binding site (see Fig. 3  and  Fig. 4) are shown in yellow, pink, and blue, respectively. The conservation track is shown as dark blue peaks, above green alignments showing conservation to medaka, tetraodon, fugu, and zebrafish, from top to bottom. (C) GFP reporter expression pattern driven by the 190 bp enhancer in a 5 dpf (stage 22, (Swarup, 1958)) stickleback embryo. Strong expression was seen in the distal edge of the developing pectoral fin (arrow), the heart (asterisk), and the distal edge of the median fin (arrowhead). (D) Confocal projection of GFP reporter expression in the ventral pharyngeal tooth plate in a ~10 mm stickleback fry. Expression was observed in the epithelium of developing tooth germs (arrow) and the odontogenic mesenchyme (arrowhead) in the cores of ossified teeth. Bones are fluorescently stained with Alizarin red. (E) GFP reporter expression in the oral teeth (arrow) of a 30 dpf stickleback fry. GFP in the lens is an internal control for the zebrafish hsp70 promoter used in the transgenic construct. Scale bars=200 µm.