Cryptic symbioses in the evolution of microbial eukaryotes

The function of microbial ecosystems is often dependent on symbiotic interactions between microbes.

Such interactions are critical for essential biogeochemical processes such as global carbon, nitrogen and sulfur cycling.

To date, microbial symbiosis research has focused on understanding interactions between prokaryotes (bacteria and archaea), however less is known about symbiosis between prokaryotes and single-cell (SC) eukaryotes (protists). The enclosed project will test whether protists engage in diverse and cryptic symbioses with other microbes.

Using the latest in SC sorting methods, thousands of protist cells and their attached microbial consortia will be isolated.

Using simultaneous SC genomics and transcriptomics, we will determine the nature of symbiotic interactions between eukaryotes and prokaryotes in nature at a large-scale.

We will test the evolutionary history of symbiosis using phylogenetic methods to determine whether the ability to interact with other microbers has been inherited vertically throughout eukaryotic evolution or represent recent additions to eukaryotic genomes (gene transfers or innovations).

These studies will allow us to understand how the eukaryotic cell has evolved to interact with other organisms through an unbiased lens.

These data can inform other research sectors such as understanding how parasitic eukaryotes interact with other microbes in host environments or the role of protist:microbe interactions in global biogeochemical processes.