The SPS sequences from the two pufferfish species Fugu and Tetraodon and zebrafish Danio rerio were aligned with the corresponding sites of Drosophila E(spl) genes and with the sites identified in h/E(spl) genes of higher vertebrates. Drosophila SPS sequences from , higher vertebrate SPS sequences according to . For retrieval of fish SPS sequences see Materials and Methods as well as additional file 6. The consensus sequence (RTGRGAR) for binding of Su(h) proteins as experimentally defined by  is shown two lines below the SPS sequence of Danio. The hexamer motifs are boldly underlined. Single base substitutions to the higher vertebrate Su(h) binding motif found in fish sequences are also underlined. Dm, Drosophila melanogaster; Dr, Danio rerio; Fr, Fugu rubripes; Hs, Homo sapiens; Mm, Mus musculus; Tn, Tetraodon nigroviridis; Xl, Xenopus laevis.