<p>A rooted phylogenetic tree was constructed from a ClustalW sequence alignment of vertebrate and invertebrate BA receptors, using MEGA 4 <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0001523#pntd.0001523-Tamura1" target="_blank">[35]</a>. Included in the alignment are 15 predicted <i>Schistosoma mansoni</i> and <i>S. japonicum</i> BA GPCR sequences, of which nine clustered together into a separate clade (SmGPR). The receptor described in this paper, SmGPR-3 is identified by an open square (□). Other <i>S. mansoni</i> receptors are marked with solid squares (▪) and <i>S. japonicum</i> receptors are marked with solid triangles (▴). Sequences are identified by their accession numbers and the species names are abbreviated as follows: A.e. (<i>Aedes aegypti</i>), A.i. (<i>Agrotis ipsilon</i>), A.m. (<i>Apis mellifera</i>), B.m. (<i>Bombyx mori</i>), B.t. (<i>Bos taurus</i>), C.e. (<i>Caenorhabditis elegans</i>), C.f. (<i>Canis familiaris</i>), C.p. (<i>Cavia porcellus</i>), D.m. (<i>Drosophila melanogaster</i>), D.j. (<i>Dugesia japonica</i>), D.r. (<i>Danio rerio</i>), H.s. (<i>Homo sapiens</i>), H.v. (<i>Heliothis virescens</i>), M.b. (<i>Mamestra brassicae</i>), M.m. (<i>Mus musculus</i>), M.mul. (<i>Macaca mulatta</i>), P.a. (<i>Periplaneta americana</i>), P.x. (<i>Papilio xuthus</i>), R.n. (<i>Rattus norvegicus</i>), S.j. (<i>S. japonicum</i>), S.med. (<i>Schmidtea mediterranea</i>), S.l. (<i>Spodoptera littoralis</i>) and S.s. (<i>Sus scrofa</i>). Predicted <i>S. mansoni</i> coding sequences are identified by their “Smp” designation obtained from the <i>S. mansoni</i> Genome database (<i>S. mansoni</i> GeneDB) and the corresponding GenBank Accession number. H1–H4, histamine type 1–4 receptors; D1–D5, dopamine type 1–5 receptors; A, adrenergic receptors; 5HT, serotonin (5-hydroxytryptamine) receptors; mACh, muscarinic acetylcholine receptors; OA/TA, octopamine/tyramine receptors.</p
