Evolutionary microbiologist Dr Anja Spang investigates archaea. ‘These are the single-celled microorganisms which form one of two primary domains – the other being bacteria. Initially, the archaea were mainly known for their ability to survive in extreme environments. But it has since become clear that they occur almost everywhere on Earth. They are not only found on our bodies, but also in soils, lakes, the ocean and in sediments.
‘Although the archaea form a primary branch in the tree of life just like bacteria, they are much less studied so far. For example, many details regarding their role in natural ecosystems and in the evolution of life remain unknown. Our group has contributed to recent research which suggests that the complex eukaryotic cells - which comprise organisms such as algae, protists, plants, fungi and animals - originated from a symbiosis between archaea and bacteria.’
With my research team at NIOZ, we now aim to further illuminate the role of Archaea in life’s evolution and elucidate how symbiotic interactions have shaped microbial diversity. Furthermore, we are interested to understand how symbiotic archaea contribute to the structure of microbial communities, especially in the poorly investigated marine environments such as the deep waters, sediments and hydrothermal vents. The DPANN archaea are particularly interesting in this context because they comprise a very diverse group of symbiotic archaea which form an early branch in the tree of life. They may not only have played an important role in the early evolution of life but are also thought to have a big impact on other organisms in the environment. Just like viruses, DPANN need a host organism to get nutrients for growth. Therefore, we cannot understand microbial communities and the history of life on Earth without taking into account the DPANN archaea.’
Read more +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 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, my post-doctoral research in the lab of Thijs Ettema at Uppsala University (see links below), 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). The recent investigation of the metabolic potential of the Asgard archaea in collaboration with the Ettema lab, has recently led us to propose an updated scenario on the origin of the eukaryotic cell - the reverse syntrophy hypothesis - from a symbiosis between an hydrogen or electron producing Asgard-archaeal ancestor and (a) bacterial partner(s) (Spang et al., 2019).
With my research team at NIOZ, we aim to further illuminate the role of Archaea in the evolution of life on Earth (Spang and Offre, 2019) and to elucidate the extent to which syntrophic interactions and symbioses have enabled major transitions in the Tree of life (ToL) and contribute to the structure and evolution of microbial communities. In particular, we are interested in illuminating the evolutionary and ecological role of DPANN archaea, which comprise a large radiation of putative archaeal symbionts suggested to form an early diverging branch in the ToL (Dombrowski et al., 2019).
I) Provide insights into the biology and evolution of archaea affiliating with the tentative DPANN superphylum, a group of archaea recently discovered using metagenomics approaches (Rinke et al., 2013; Castelle et al., 2015).
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 (Petitjean et al., 2014; Raymann et al., 2015; Williams et al., 2017).
II) Shed light into the evolution and diversification of archaeal metabolism (reviewed in Adam et al., 2017 and Spang et al., 2017).
The origin and evolution of important metabolic features of Archaea is poorly understood and recent metagenomic studies have indicated that our view on the role of Archaea in biogeochemical cycles is extremely biased towards cultivated representatives. The available metagenome data represents a gold mine to deepen our insights into aspects such as the evolution of methanogenesis/methane oxidation, hydrogen-based metabolisms, autorophic carbon fixation pathways and hydrocarbon degradation and will allow to generate testable hypothesis on the functional role of the various archaeal lineages and their biotechnological potential. Furthermore, this data, together with novel approaches to reconstruct protein history evolution (Williams, et al., 2017), will allow to shed insights into the dark ages of cellular evolution.
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%)
5/2013-8/2017: Postdoctoral researcher at the Department of Cell- and Molecular Biology, Science for Life Laboratory, Uppsala University, Sweden; Group Leader: Dr. Thijs Ettema
Main topics: Archaeal roots of Eukaryotes, Comparative genomics of (Asgard) archaea
1/2009-5/2013: PhD studies in microbial comparative genomics in the Department of Genetics in Ecology at the University of Vienna (Austria)
Topic: Genome Analyses and Comparative Genomics of Thaumarchaeota
2007-2008: Master studies in microbial genomics, University of Bergen (Norway); Topic: Metagenomics of archaeal viruses from Icelandic hot springs
January 2017: NWO Women In Science Excel (WISE) tenure track award providing five years of funding for establishing an independent research group
December 2016: Tenure track position at NIOZ, Netherlands Institute for Sea Research,
November 2016: VR starting grant from the Swedish Research council (Vetenskapsrådet) (duration: four years)
December 2013: Marie-Curie Intra-European Fellowship by the European Commission (duration: two years, starting date autumn 2014)
December 2013: Award of Excellence 2013 for my PhD thesis from the Austrian Minister of Science and Research
2010-2012: Two years of research funded by a DOC-fFORTE fellowship from the Austrian Academy of Sciences
email: anja.spang@nioz.nl or anja.spang@icm.uu.se
twitter: anjspa1
http://www.ettemalab.org
http://www.ettemalab.org/anja-spang/
http://katalog.uu.se/empInfo/?languageId=1&id=N13-996