Fig. 7a Fig. 7b

Figure 7 - A. Serotonin synthetic pathway. Tryptophan (Trp) is first hydroxylated to 5-hydroxytryptophan (5-HTP) by an aromatic amino acid (AAA) hydroxylase, then decarboxylated to yield serotonin (5-HT, 5-hydroxytryptamine) by an aromatic amino acid decarboxylase. B. Summary of characteristics of serotonin-deficient mutants.