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

Información del proyecto

TACKLE

Identificador del acuerdo de subvención: 695192

DOI

10.3030/695192

Proyecto cerrado

Fecha de la firma de la CE 28 Julio 2016

Fecha de inicio 1 Agosto 2016

Fecha de finalización 31 Julio 2022

Financiado con arreglo a

• EXCELLENT SCIENCE - European Research Council (ERC)

Coste total

€ 2 500 000,00

Aportación de la UE

€ 2 500 000,00

Coordinado por

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)

Período documentado: 2021-02-01 hasta 2022-07-31

Resumen del contexto y de los objetivos generales del proyecto

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.

Trabajo realizado desde el comienzo del proyecto hasta el final del período abarcado por el informe y los principales resultados hasta la fecha

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.

Avances que van más allá del estado de la técnica e impacto potencial esperado (incluida la repercusión socioeconómica y las implicaciones sociales más amplias del proyecto hasta la fecha)

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