Tracing the origin and evolution of specialized biosynthetic pathways in marine organisms

Harmful algal blooms (HABs) pose public health and ecological risks in aquatic environments. HABs drive the bioaccumulation of a specific family of specialized metabolites known as "kainoids." Kainoid derivatives, such as kainic acid (KA) and domoic acid (DA), are among the most toxic marine-derived metabolites produced by a limited number of algal species. While recent studies have provided insights into the molecular basis of KA and DA production in red algae and diatoms, knowledge of the biosynthesis of kainoids remains insufficient. In a new report published in <i>mBio</i>, Wood-Rocca et al. decode the DA biosynthetic route in the widespread Western Pacific benthic diatom <i>Nitzschia navis-varingica</i> (S. M. Wood-Rocca, N. Allsing, Y. Ashida, M. Mochizuki, et al., mBio 16:e02079-25, 2025, https://doi.org/10.1128/mbio.02079-25). We discuss how evolutionary genomics studies bridge the gap between fundamental biology and applied environmental and biotechnological research, enhancing our ability to understand, predict, and harness marine natural products.