Figure 3

Conserved transcription factor (sub-) networks in eumetazoa. Conserved TF interactions across five eumetazoan species were identified and example subnetworks are shown. Presence of these interactions in all five species implies they existed in the last common ancestor before divergence of Radiata and Bilateria. A) The TF network mainly comprised of Homeobox and bZIP TFs. Organisms are ordered according to evolutionary distance. Orthologous relations (dashed lines) are drawn only between adjacent organisms for brevity. Loops indicate homodimeric interaction. B) Notable conserved interactions: Additional homeobox protein interactions essential in early development of all eumetazoans and several TF interactions expanded in particular lineages are drawn. Species order and TF shapes in B are as in A. C) Helix-loop-helix domain in MAX proteins are aligned by Clustal × [44] and conservation in each residue is depicted. D) Phylogeny of MAX proteins estimated by the Mega 3 package [45] using the maximum-parsimony distance. Numbers along branches refer to bootstrapped values.