Phylogenetic relationship of the Otp gene family. A, MP phylogenetic reconstruction of Otp, Otd, Otx, and Antp protein sequences. BPP/MP/NJ: Bayesian posterior probability, Maximum Parsimony, Neighbour Joining bootstrap support. A dash denotes BPP values below 95% and bootstrap values below 80%. Podocoryne carnea Tbx4/5 protein was used as an outgroup. B, List of taxa with abbreviations (see Methods for accession numbers).