 This enrichment was consistent with two biosynthetic pathways.The labeling pattern determined that domoic acid can be biosynthesized by an isoprenoid intermediate in combination with a tricarboxylic acid (TCA) cycle intermediate.In 2018, using growth conditions known to induce domoic acid production in "Pseudo-nitzschia multiseries", transcriptome sequencing successfully identified candidate domoic acid biosynthesis genes responsible for the pyrrolidine core.