Table 2.
Summary of previous work and main conclusions
| Paper | Genes | Non-Bilaterians | Methods | Conclusions |
|---|---|---|---|---|
| Iyer et al.42 | AAAH, AADC, BH, PNMT, COMT, HNMT, MAO | 0 | Similarity; NJ Tree; ML Tree; Bayesian Tree | DDC and HDC diverge in Metazoa TH sister to TPH and PAH |
| Caveney et al.26 | SLC6 | 0 | PCR; Similarity; NJ Tree | 3 transporter Clades Predate Bilateria |
| Anctil41 | AAAH, AADC, BH, PNMT, MAO, GPCRs, SLC6, VMAT | Nematostella vectensis (Renilla sp.) | Similarity; Motif; NJ Tree; ML Tree | Homologues of most genes found in N. vectensis |
| Cao et al.11 | AAAH | 2 (N. vectensis; Trichloplax adhaerens) | Similarity; NJ Tree; ML Tree | TPH and PAH sisters TH and TPH Bilaterian |
| Siltberg-Liberles et al.43 | AAAH | 0 | Bayesian Tree | TPH and TH are sisters Duplications in Metazoa |
| Kutchko and Siltberg-Liberles44 | AADC, BH, MAO | 0 | Similarity; ML Tree | DDC Homologue to TDC and HDC, Metazoan unique TBH homologue of DBH and MOXD PNMT Vertebrate Specific |
| Krishnan and Schiöth45 | GPCRs, AAAH, AADC, BH, PNMT | 4 (N. vectensis; T. adhaerens; Mnemiopsis leidyi; Amphimedon queenslandica) | Similarity | Whole Pathway Present in Cnidaria DDC, DBH and GPCRs in other non-bilaterians |
| Francis et al.39 | AADC, BH, MAO | 2 Placozoans; 36 Cnidarians; 20 Sponges; 13 Ctenophores | Similarity; ML Tree | DBH Homologues in non-bilaterians DDC Ortholog in Hydrozoa DDC Homologues in non-bilaterians |
| Moroz et al.37 | AAAH, AADC, SLC6, BH, PNMT, VMAT, 5HT3R | T. adhaerens; 6 Cnidarians; M. leidyi; Pleurobrachia bachei; A. queenslandica | Uncertain | Only DDC and DBH have Orthologs in non-Bilateria |
AAAH aromatic amino acid hydroxylase, AADC aromatic amine decarboxylase, BH beta hydroxylase, PNMT phenylethanolamine-N-methyltransferase, VMAT vesicular monoamine transporter, SLC solute ligand carrier, MAO monoamine oxidase, COMT catechol-O-methyltransferase, HNMT histamine-N-methyltransferase, GPCR g-protein coupled receptor, 5HT3R 5-hydroxytryptamine receptor 3, PAH phenylalanine hydroxylase, TPH tryptophan hydroxylase, TH tyrosine hydroxylase, DDC dopa decarboxylase, TDC tyrosine decarboxylase, HDC histidine decarboxylase, DBH dopamine beta hydroxylase, TBH tyramine beta hydroxylase, MOXD monooxygenase DBH-like, NJ neighbourhood joining, ML maximum likelihood.