- Media highlights
- Thijs Ettema
- Post Docs
- PhD Students
- Spang Branch
I have always been fascinated by the evolution of life on Earth, eukaryogenesis and the role symbiosis has played in the major transitions of life. My past research on Archaea in has been driven by the aim of getting a better understanding of the diversity and genomic potential of Archaea and their relationship to Bacteria and eukaryotes. For example, during the past years in the Ettema-Lab at Uppsala University, our research focused on the investigation of Lokiarchaeota (Spang et al., 2015) and related lineages, which together comprise the Asgard superphylum and have proven to be key for our understanding of eukaryogenesis (Zaremba-Niedzwiedzka et al., 2017). We could show that Asgard archaea form a monophyletic group with Eukaryotes and encode various eukaryotic signature proteins, suggesting that they have been important in the early stages of the origin of the eukaryotic cell (Spang et al., 2015, Zaremba et al., 2017, Spang et al., 2017, Eme et al., 2017). In collaboration with Thijs Ettema, we try to further extend the current understanding of the evolution and metabolic potential of the Asgard superphylum.
The major focus of my prospective research at Uppsala University (VR starting grant) and the Netherlands Institute for Sea Research (tenure track scientist and WISE fellow), is to study archaea affiliating with the tentative DPANN superphylum, a group recently discovered using metagenomics approaches. DPANN archaea comprise members with extremely small genomes and cell sizes and include the so far only known parasites within the archaea. Representatives of this extremely diverse group seem to be widespread globally and occur in most thinkable environments on Earth. Interestingly, genomes of various and phylogenetically diverse DPANN archaea have also been reconstructed from marine sediments and water samples. However, thus far the function and importance of DPANN archaea in marine ecosystems and food webs is unknown. In addition, while initial analyses suggest that many members of the DPANN are dependent on syntrophic or symbiotic interactions with other organisms, knowledge about the nature of these interactions as well as the metabolic potential of these organisms is scarce. Finally, the evolution of DPANN lineages and their phylogenetic placement is currently unclear. Using a combination of different approaches such as metagenomics, phylogenomics and comparative genomics as well as microbial ecology techniques and cultivation, my research team is addressing fundamental questions on the extend, functional importance and evolution of symbiosis in (DPANN) archaea, with a particular focus on little explored dark oceanic regions.
Finally, I have an interest in the early diversification of microbial metabolic and enzymatic diversity, and additional research topics focus among others on the evolution of methanogenesis/ methane oxidation in Archaea, the diversity of NiFe-Hydrogenases etc.. The vast amount of recently discovered microbial taxa have started to unveil a more complex evolutionary history of microbial enzymatic diversity than assumed previously and revealed a large amount of novel enzymes of unknown function. Certainly, the available metagenome data represents a gold mine not only for an increased understanding of microbial metabolism and evolution but also for the functioning of ecosystems such as the dark ocean.
Current positions (since September 2017):
Tenure track researcher at NIOZ, Netherlands Institute for Sea Research (80%) VR-funded researcher at Uppsala University, Department of Cell- and Molecular Biology (20%)