Multiple sequence alignments showing portions of the forkhead domain and C-terminus of FOXE1 proteins. (A) The avian FOXE1 proteins has lost the engrailed homology motif 1 (Eh1) and the aromatic repression domain during evolution, due to the two microdeletions, probably occurring in the lineage of birds. The aromatic repression domain is highlighted with the yellow box and the Eh1 motif with the red box in the aligned protein sequences. The numbers on the left indicate the positions of amino acid residues in the respective sequences. The positions for FOXE1 of T. guttata (zebra finch) are enumerated from the forkhead domain due to the missing N-terminal sequences.