|Title||Biosynthesis of the neurotoxin domoic acid in a bloom-forming diatom|
|Publication Type||Journal Article|
|Year of Publication||2018|
|Authors||Brunson JK, McKinnie SMK, Chekan JR, McCrow JP, Miles ZD, Bertrand EM, Bielinski VA, Luhavaya H, Oborník M, G. Smith J, Hutchins DA, Allen AE, Moore BS|
Algal blooms can devastate marine mammal communities through the production of neurotoxins that accumulate within the food web. Brunson et al. identified a cluster of genes associated with biosynthesis of the neurotoxin domoic acid in a marine diatom (see the Perspective by Pohnert et al.). In vitro experiments established a series of enzymes that create the core structure of the toxin. Knowledge of the genes involved in domoic acid production will allow for genetic monitoring of algal blooms and aid in identifying conditions that trigger toxin production.Science, this issue p. 1356; see also p. 1308Oceanic harmful algal blooms of Pseudo-nitzschia diatoms produce the potent mammalian neurotoxin domoic acid (DA). Despite decades of research, the molecular basis for its biosynthesis is not known. By using growth conditions known to induce DA production in Pseudo-nitzschia multiseries, we implemented transcriptome sequencing in order to identify DA biosynthesis genes that colocalize in a genomic four-gene cluster. We biochemically investigated the recombinant DA biosynthetic enzymes and linked their mechanisms to the construction of DA’s diagnostic pyrrolidine skeleton, establishing a model for DA biosynthesis. Knowledge of the genetic basis for toxin production provides an orthogonal approach to bloom monitoring and enables study of environmental factors that drive oceanic DA production.
“By identifying the genes that encode domoic acid production, we can now ask questions about various oceanic conditions that turn the genes on or off,” said Scripps Institution of Oceanography and JCVI PhD student Patrick Brunson, one of two lead authors on the study. “This knowledge will allow us to track the development of bloom toxicity at the genetic level.”
By showing how the genes for domoic acid production are turned on in culture, the authors suggest a way to connect the oceanic conditions that drive algal bloom evolution to the development of toxin production.