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Researchers from the Earlham Institute, in collaboration with The Department of Biology at the University of Oxford, discovered three previously unrecognised lineages of the protist Bodo, each with its own bacterial endosymbiont (a symbiotic organism living within the body of its host).
Bodo is a genus of heterotrophic (a living organism that obtains nutrition from other plants, animals, or microorganisms) protists that are common in fresh and brackish waters and soil. They are the closest known free-living relatives of Trypanosoma, a parasitic protist that causes major human diseases including Human African trypanosomiasis (sleeping sickness).
Until now, genomic studies of Bodo came from a single species, Bodo saltans. This research isolated, sequenced, and assembled genomes for seven uncultured Bodo spp. single cells from a freshwater sample, revealing three potentially novel species that diverge significantly from B. saltans. Additionally, the researchers identified that each novel species carried its own distinct species of the Holosporales bacteria.
Published in Microbial Genomics, the study forms part of the Darwin Tree of Life project and contributes to the Institute's Decoding Biodiversity programme, which is developing a robust single-cell sequencing pipeline for protists from environmental samples.
Protists are hugely diverse and are notoriously complex to sequence and analyse, but they hold incredible potential for biotechnology applications, addressing challenges in climate change and biodiversity, and answering fundamental questions about evolution.
Most studies until now have used cultured cells or bulk environmental samples to classify microbial eukaryotes. However, these methods fail to distinguish between closely related species and miss their associated bacterial symbionts entirely, obscuring the true complexity of these microscopic ecosystems.
