Species specific gene expression dynamics during harmful algal blooms

Gabriel Metegnier (1, 2) , Sauvann Paulino (2) , Pierre Ramond (3, 2) , Raffaele Siano (2) , Marc Sourisseau (2) , Christophe Destombe (2, 1) , Mickael Le Gac (2)

1 EBEA - Biologie évolutive et écologie des algues = Evolutionary Biology and Ecology of Algae
2 IFREMER - Institut Français de Recherche pour l'Exploitation de la Mer
3 ADMM - Adaptation et diversité en milieu marin

Harmful algal blooms are caused by specific members of microbial communities. Understanding the dynamics of these events requires comparing the strategies developed by the problematic species to cope with environmental fluctuations to the ones developed by the other members of the community. During three consecutive years, the meta-transcriptome of micro-eukaryote communities was sequenced during blooms of the toxic dinoflagellate Alexandrium minutum. The dataset was analyzed to investigate species specific gene expression dynamics. Major shifts in gene expression were explained by the succession of different species within the community. Although expression patterns were strongly correlated with fluctuation of the abiotic environment, and more specifically with nutrient concentration, transcripts specifically involved in nutrient uptake and metabolism did not display extensive changes in gene expression. Compared to the other members of the community, A. minutum displayed a very specific expression pattern, with lower expression of photosynthesis transcripts and central metabolism genes (TCA cycle, glucose metabolism, glycolysis…) and contrasting expression pattern of ion transporters across environmental conditions. These results suggest the importance of mixotrophy, cell motility and cell-to-cell interactions during A. minutum blooms.

Mots clés: Marine biology; Microbial ecology; Transcriptomics

Domaines: Biodiversité et Ecologie; Microbiologie et Parasitologie; Génomique, Transcriptomique et Protéomique [q-bio.GN]; Océanographie

Gabriel Metegnier, Sauvann Paulino, Pierre Ramond, Raffaele Siano, Marc Sourisseau, et al.. Species specific gene expression dynamics during harmful algal blooms. Scientific Reports, 2020, 10, pp.6182. ⟨10.1038/s41598-020-63326-8⟩. ⟨hal-02550673⟩