PurSUit: Discovery and phylogenetic analysis of unknown eukaryotic diversity using targeted single-cell analyses of heterotrophic flagellates

PurSUit: Discovery and phylogenetic analysis of unknown eukaryotic diversity using targeted single-cell analyses of heterotrophic flagellates Little is known about much of the diversity of single-celled eukaryotes, which are called protists. Free-living, non-pathogenic protists that eat other cells and have a flagellum (or two), are especially understudied. In fact, new phyla and even ‘kingdoms’ of protists are still being discovered at a surprising rate. Thus, approaches must be developed to speed the rate of discovery and bridge this gap in our understanding. In this work, the researchers will develop and use state-of-the-art methods to discover, characterize, and sequence, previously unknown, orders, classes, phyla, and maybe even kingdoms of protists. These data will not only provide insight into the diversity of eukaryotic microbes that currently inhabit our planet but will also help to understand the nature of eukaryotes and the cells that existed over a billion years ago. Because there is so much still to discover, new species lurk in nearly any pond. Therefore, with the goal of including the public in the naming, discovery, and description of new protist species, researchers will also bring this world of discovery to community college and underserved junior-high students in Phoenix AZ. Heterotrophic flagellates are a guild of protists that span the tree of eukaryotes and play important roles in biogeochemical processes, especially aquatic carbon cycling. They are also important for understanding deep eukaryotic evolution. However, very little is known about the biology of heterotrophic flagellates. Molecular data are particularly limited for heterotrophic flagellates that inhabit freshwater environments. Given the diversity of heterotrophic flagellates known or predicted to exist, higher throughput methods are required to ensure broad sampling. Here, the researchers will use medium-throughput methods to generate over 500 single-cell genomes or transcriptomes of freshwater heterotrophic flagellates. They will also develop high-throughput approaches to sequence tens to hundreds of thousands of single cell transcriptomes. These data will be used to phylogenetically place newly discovered heterotrophic flagellate lineages at the order- and class- or even phylum- and kingdom-levels. This knowledge would help refine the eukaryotic tree of life and transform our current understanding of eukaryote evolution and diversification over the last 2 billion years. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.