Figure 1

Selective divergence of shhb noncoding sequences from those of shh(a) genes. Vista plot of Shuffle-Lagan alignment of sonic hedgehog (a) (shha) and sonic hedgehog b (shhb) gene loci from different vertebrate species. The zebrafish shha locus is the base sequence with which the other hedgehog's loci are compared. The peaks with more than 70% identity in a 50 base pair window are highlighted in color (color legend at the top). At the bottom of the plot, a scheme of the zebrafish shha locus marks the position of the exons, known cis-regulatory elements, and the 3'-untranslated region (UTR). The phylogenetic tree on the left side of the plot represents the evolutionary relationship of vertebrates. ar, activation region; CNS, conserved noncoding sequence; E, exon; kb, kilobase; UTR, untranslated region; zfish, zebrafish.