Fig. 1. Sequence analysis and phylogeny of the new bHLH transcription factor Him. (A) Genomic organization of the him/her5 locus. The coding region is interrupted by three introns, the bHLH domain being encoded by exons E2 and E3. Note that the first exon of him is within the domain identified as necessary for MH expression of her5 (Tallafuss and Bally-Cuif, 2003). (B) Phylogenetic tree of the zebrafish Her family, showing relationship between known and predicted Her proteins. The alignment used for tree construction was obtained using the VectorNTI software, and is based on full-length sequences. Paired genes are boxed in blue, and individual pairs are marked with the same symbol (oval, rectangle or diamond). Accession numbers for the proteins used in this tree are: Her5 (NP_571152), Her1(NP_571153), Her7(NP_571684), Her4(NP_571165), Her2(NP_571164), Her3(NP_571155), Her9(NP_571948) and Her6(NP_571154). Proteins predicted by The Wellcome Trust Sanger Institute (http:www.ensembl.org) are: Her11, Her12, Her13 and Hes6. (C) Sequence alignment of Her1, Her5 and Him. Basic domains are overlaid with red asterisks, Helix 1 domains with dark blue, loop domains with green, Helix 2 domains with light blue, orange domains (H3/H4) with orange stars and WRPW tetrapeptides