Fig. 1

 Comparison of zebrafish Insm1a and Insm1b to mammalian and invertebrate homologues. (A) Amino acid alignment of predicted zebrafish Insm1a (AAZ94623) and Insm1b (AAZ94624) to human (NP_002187) and mouse (NP_058585) INSM1. Amino acid identity (asterisks) and similarity (periods) are indicated below the aligned sequences. Insm1 is predicted to contain an amino-terminal SNAG motif (blue), a putative nuclear localization sequence (green), and five (numbered) carboxy-terminal Cys₂-His₂ zinc fingers (red). Zinc coordination residues of each zinc finger are highlighted in red. (B) Protein schematic showing the predicted domain structure of Insm1, Nerfin-1, and EGL-46 proteins. Shown are the amino-terminal SNAG repressor domains (blue), putative nuclear localization signals (green) and carboxy-terminal Cys₂-His₂ zinc fingers (red). Proteins were drawn to scale and aligned about the highly conserved EIN domain. Zinc fingers are numbered based on homology as in (A) and indicated in invertebrate homologues. Zinc finger 3 of EGL-46 (asterisk) does not share the conservation seen in other EIN homologues. Numbers in brackets indicate the amino acid length. (C) Phylogenetic analysis showing zebrafish Insm1a and Insm1b (highlighted in orange) are more similar to mammalian INSM1 than to another INSM1-like protein, MLT1. We have identified a zebrafish MLT1-like gene from genomic sequences that is more similar to mammalian MLT1 than to INSM1. z, zebrafish; h, human; and m, mouse.