Robust Dinoflagellata phylogeny inferred from public transcriptome databases

Dinoflagellates are dominant members of the plankton and play key roles in ocean ecosystems as primary producers, predators, parasites, coral photobionts, and causative agents of algal blooms that produce toxins harmful to humans and commercial fisheries. These unicellular protists exhibit remarkable trophic and morphological diversity and include species with some of the largest reported nuclear genomes. Despite their high ecological and economic importance, comprehensive genome (or transcriptome) based dinoflagellate trees of life are few in number. To address this issue, we used recently generated public sequencing data, including from the Moore Microbial Eukaryote Transcriptome Sequencing Project, to identify dinoflagellate-specific ortholog groups. These orthologs were combined to create a broadly sampled and highly resolved phylogeny of dinoflagellates. Our results emphasize the scope and utility of public sequencing databases in creating broad and robust phylogenies for large and complex taxonomic lineages, while also providing unique insights into the evolution of thecate dinoflagellates.