Msx Phylogeny based upon the full Msx alignment. Relationships among 44 metazoan Msx proteins were estimated by neighbor-joining (see methods). The tree is rooted using the two cnidarian sequences. Numbers at nodes indicate the percentage of replicates in which a given partition between taxa was observed in 1000 replicates of the bootstrap . Circles indicate the major taxonomic group represented by each sequence (Hemi = Hemichordata, Ceph = Cephalochordata, Chon = Chondrichthyes, Amphib = Amphibia, Marsup = Marsupialia, Artio = Artiodactyla). Species abbreviations are provided in the methods.