Fig. 3. Exon-intron genomic structure of Dmbx genes. Coding sequence exons are shown as rectangles; homeodomains are indicated by grey shadows, OAR domains by dotted boxes and the conserved domains similar to the GEH/eh-1 domain by black boxes. The numbers at the corner of rectangles indicate the nucleotide position at the exon-intron boundary. AmphiDmbx genomic sequences are available in GenBank (Accession Numbers AY588477 and AY588478). Genomic sequences of other species are from GenBank (human, NT 004852; mouse, NT 039264; Takifugu CAAB01001099) and the JGI website (ascidian). Each genomic structure was deduced from comparison of genomic sequence with cDNA sequence in accordance with the GU-AG splice site rule.