TACK Superphylum and Lokiarchaeota Evolution: Dissecting the Ecology and Evolution of Archaea to Elucidate the Prokaryote to Eukaryote Transition

Informazioni relative al progetto

TACKLE

ID dell’accordo di sovvenzione: 695192

DOI

10.3030/695192

Progetto chiuso

Data della firma CE 28 Luglio 2016

Data di avvio 1 Agosto 2016

Data di completamento 31 Luglio 2022

Finanziato da

• EXCELLENT SCIENCE - European Research Council (ERC)

Costo totale

€ 2 500 000,00

Contributo UE

€ 2 500 000,00

Coordinato da

UNIVERSITAT WIEN
Austria

Periodic Reporting for period 4 - TACKLE (TACK Superphylum and Lokiarchaeota Evolution: Dissecting the Ecology and Evolution of Archaea to Elucidate the Prokaryote to Eukaryote Transition)

Periodo di rendicontazione: 2021-02-01 al 2022-07-31

Sintesi del contesto e degli obiettivi generali del progetto

Archaea arose as one of the earliest life forms on Earth probably at about the same time as Bacteria. They have unique cell membranes and many of their cellular machineries are primordial versions of those in complex multicellular life forms (Eukaryotes). This project investigated two lineages of Archaea that can give clues to some of the most fundamental questions in biology: how did organisms expand from hot into moderate and cold environments on the early Earth and what kind of archaeon led to the evolution of Eukaryotes by incorporating a bacterium (which later evolved into mitochondria) into its cell. Without this event, no complex life forms would exist on Earth.
To address these questions it was a major objective of this project to cultivate and study organisms of two crucial lineages: Lokiarchaea of the new phylum Asgardarchaeota that are the closest known living relatives to Eukaryotes and thermophilic Thaumarchaeota from hot springs whose descendants have radiated into moderate environments on Earth.

Lavoro eseguito dall’inizio del progetto fino alla fine del periodo coperto dalla relazione e principali risultati finora ottenuti

Novel habitats of Asgardarchaeota were discovered and well and stably growing enrichments of the lineage Lokiarchaeia were obtained. Their cells revealed an unprecedented cellular and cell wall complexity that shows the evolutionary emergence of actin-based cytoskeleton long before the emergence of Eukaryotes and a unusual and diverse cell wall that might particularly well interact with its biotic and abiotic environment. A thermophilic ammonia oxidizing Thaumarchaeote was obtained in pure culture and together with 38 further Thaumarchaeota genomes was used to reconstruct the evolution and ecological adaptations of this group into moderate environments. This revealed an enormous repertoire of proteins to cope with oxygen stress, apparently to alleviate the elevated amounts of oxygen in environments of decreasing temperature.
Our work was published in 15 peer-reviewed publications and presented on 3 conferences. At least 6 further publications are currently in preparation and more are expected to come.

Progressi oltre lo stato dell’arte e potenziale impatto previsto (incluso l’impatto socioeconomico e le implicazioni sociali più ampie del progetto fino ad ora)

The collaboration with a group at ETH Zurich experienced in cryo-EM and other imaging techniques has allowed to get unprecedented insights into features of the cultivated Lokiarchaeote that have never been seen before. Since this enrichment is the first of its kind that reaches high cell densities, it representes a tractable organism for many investigations to come, including metabolic reconstructions, identification of cell wall components, cell division machinery and other components that will shed light on the early evolution of machineries which led to the emergence of eukaryotes.

Sampling on top of the volcano in Vulcano island, Liparic islands

Researchers walking by a volcano crater in Etna, Sicily