Vertebrate LMX1A and LMX1B subclades are depicted in red and blue, respectively, and the predicted LMX1 peptide from the Japanese lamprey (L. japonicum JL14965) is in purple (REF #1). Non-vertebrate, chordate out-group sequences (black) consist of a pair of duplicated LMX1 genes, lmx-like and lmx, which are present in the genomes of each of the two ascidians Ciona intestinalis and Ciona savignyi. Node values represent posterior probabilities after phylogenetic analysis via Bayesian inference.