UNC Department of Marine Sciences graduate student Weida Gong along with coauthors Jamie Browne, Nathan Hall, David Schruth, Hans Pearl and Adrian Marchetti have published a study in the ISME Journal. The study explores combining traditional methods with molecular approaches in order to examine the factors leading to algal blooms. The technique (comparative metatranscriptomics) allows for comparison of gene expression from specific phytoplankton groups during an algal bloom when compared to normal conditions. These new molecular approaches will increase our understanding of algal bloom dynamics and potentially lead to the ability to predict and therefore mitigate future harmful blooms.

The samples used in the study were taken in the fall of 2012 from the North Carolina, Neuse River Estuary during a dinoflagellate bloom. Samples taken before, during and after the bloom were compared using the comparative metatranscriptomics method with samples from the surrounding area not experiencing the same algal bloom.

For more information visit…
The Marchetti Lab website
The YouTube video of Dr. Adrian Marchetti discussing the study
The UNC Endeavors story by Mary Lide Parker on this subject titled: Sequencing the Sea
The UNC news release
The original article published by The ISME Journal Multidisciplinary Journal of Microbial Ecology (doi:10.1038/ismej.2016.129)

The paper’s abstract: In coastal waters worldwide, an increase in frequency and intensity of algal blooms has been attributed to eutrophication, with further increases predicted because of climate change. Yet, the cellular-level changes that occur in blooming algae remain largely unknown. Comparative metatranscriptomics was used to investigate the underlying molecular mechanisms associated with a dinoflagellate bloom in a eutrophied estuary. Here we show that under bloom conditions, there is increased expression of metabolic pathways indicative of rapidly growing cells, including energy production, carbon metabolism, transporters and synthesis of cellular membrane components. In addition, there is a prominence of highly expressed genes involved in the synthesis of membrane-associated molecules, including those for the production of glycosaminoglycans (GAGs), which may serve roles in nutrient acquisition and/or cell surface adhesion. Biotin and thiamine synthesis genes also increased expression along with several cobalamin biosynthesis-associated genes, suggesting processing of B12 intermediates by dinoflagellates. The patterns in gene expression observed are consistent with bloom-forming dinoflagellates eliciting a cellular response to elevated nutrient demands and to promote interactions with their surrounding bacterial consortia, possibly in an effort to cultivate for enhancement of vitamin and nutrient exchanges and/or direct consumption. Our findings provide potential molecular targets for bloom characterization and management efforts.

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