Phylogram of E(spl)-C- and HES-related proteins. Unrooted Bayesian phylogram of the bHLH and orange domains of E(spl)-C bHLHs and HER-like bHLH proteins from sequenced arthropod genomes. Names of proteins and their respective species are shown in Figure 4 and in Supplemental Table 1. Phylogenetic analysis resolves three clades: (1) a large clade with representatives from all insect and crustacean genomes, including all Drosophila E(spl)-C genes, that we designate E(spl)-C bHLH-1 (green). (2) A clade with a smaller number of members but including representatives from hemimetabolous and holometabolous insects and Crustacea; we designate this clade E(spl)-C bHLH2 (light blue). (3) The final clade contains representatives from insects and includes Drosophila HER; we designate this clade Her (blue). The Daphnia protein NCBI130833 is circled in red, as it does not cluster robustly with any of these clades; however, the position of the gene that encodes it in the Daphnia E(spl)-C complex indicates that it is most likely to be a Her gene.
