Figure 3: IRX homeodomain protein sequences and their conservation . A) Multiple sequence alignment shows high conservation in the DNA binding domain of IRX protein sequences. The difference at the N-terminal can explain the recognition specificity of these proteins to target DNA sequence B) Phylogenetic tree analysis highlighting highly conserved sequences. The tree shows evolution of the IRX homeodomain and also the functional specificity of the members of the family. The tree was constructed using the maximum likelihood method and derived from multiple sequence alignments of all IRX homeodomain region. The bootstrap values at the nodes of the branches indicate the maximum-likelihood of the sequence conservation between IRX proteins.