Comparison of the intergenic regions of three dlx clusters among osteichthyans. (A) dlx1a-dlx2a (Dlx1-Dlx2) cluster. (B) dlx3b-dlx4b (Dlx3-Dlx4) cluster. (C) dlx5a-dlx6a (Dlx5-Dlx6) cluster. Sequence similarity was visualized by mVista (see Materials and methods) using stickleback as a reference. Third exons of dlx genes are shown in grey and conserved non-coding elements (CNEs) in intergenic regions are shown in purple shading. Designation of detected CNEs, namely I12.1 to I12.9, I34.1 to I34.6 and I56.1 to I56.6, are shown at the top (see Materials and methods for our criterion for CNE annotation). See Additional file 3, for comparisons including the flanking regions of the dlx clusters.