Phylogenetic reconstruction of ParaHox genes. The tree is from Bayesian likelihood analysis using MrBayes: half compatibility consensus from five million replicates, burn-in of 5,000 replicates. The tree is built with the amino-acid sequences of the homeodomain and the flanking region. Support values of branches are posterior probabilities of Bayesian likelihood. Hox1 sequences of several bilaterians are used as outgroup (black). Groupings of the ParaHox genes are strongly supported. Gsx/Gsh sequences are shown in red, Xlox sequences in blue, and Cad/Cdx in green. Yellow rectangles highlight ParaHox sequences of G. varia. Amphioxus: Branchiostoma floridae, Branchiopode: Artemia franciscana, Frog: Xenopus tropicalis, Fruit fly: Drosophila melanogaster, Human: Homo sapiens, Hydrozoa: Podocoryne carnea, Leech: Hirudo medicinalis, Limpet: Patella vulgata, Mouse: Mus musculus, Mosquito: Anopheles gambiae, Nematode: Caenorhabditis elegans, Polychaete 1: Platynereis dumerilii, Polychaete 2: Capitella teleta, Sea Anemone: Nematostella vectensis, Sea Urchin: Strongylocentrotus purpuratus, Top Shell: Gibbula varia.