Phylogenetic analysis of B. floridae and vertebrate type 1 and type 2 ORs. Neighbor-Joining tree of representative type 1 and type 2 vertebrate ORs (n = 59), 50 full-length B. floridae ORs, and one sequence from B. belcheri . The vertebrate ORs include sequences from human, mouse, fish, amphibian, chicken and lamprey. The abbreviations in the sequence names represent these species: Danio rerio (Dr), Fugu rubripes (Fr), Xenopus tropicalis (Xt), and Gallus gallus (Gg). Type 1 and type 2 designations are based on . Tree construction was based on approximately 200 amino acid positions and 1000 bootstrap replicates were conducted. The bootstrap values for nodes with less than 70% support were excluded from the tree and human and fish purinergic [GenBank:NM_002563, GenBank:CAK04925] and melanocortin receptors [GenBank:AAC13541, GenBank:NP_851301] were used to root the tree. For the complete list of vertebrate ORs included in the tree, see Additional file 2.