Abstract. Mitochondrial proteome reconstruction from eukaryotic sequence data typically relies on prediction of mitochondrial targeting signals (MTSs). How

Distant eukaryotic lineages convergently reverted from phagocytic predation to osmotrophy through co-option of ancestrally acquired bacterial genes and their subsequent mobilization via eukaryote-to-e...

Abstract. Phylogenetic trees are often inferred from protein sequences sampled from diverse taxa across the tree of life. The compositions of these amino a

The Genome Taxonomy Database (GTDB) is an initiative to establish a standardised microbial taxonomy based on genome phylogeny.

Abstract. Many countries with lower research & innovation capacity face persistent constraints in building stable research systems. Chronic underfundin

Eukaryotes originated from the symbiosis of an Asgard archaeon, the alphaproteobacterial ancestor of mitochondria, and possibly additional bacterial contributions. This transition occurred in redox-transition environments such as microbial mats or shallow sediments ~2 billion years ago, when atmospheric oxygen was far lower than today. We investigated Asgard-enriched microbial mats from the low-oxygen, sulfidic Catherine volcano lake (Afar region, Ethiopia), mimicking early Proterozoic conditions. 16S rRNA gene metabarcoding, metagenomics, and metagenome-assembled genome analyses across redox-stratified layers of in situ and mesocosm-maintained mats revealed that Asgardarchaeota thrived in the sulfate-reduction zone, mainly co-occurring with Desulfurobacterota-Myxococcota, among others. Lokiarchaeia and Thorarchaeia preferred anoxic layers. Within Heimdallarchaeia, Heimdallarchaeales were enriched in upper layers, correlating with oxygen-tolerant hydrogenase and sulfate-reduction genes, and Hodarchaeales, in anoxic layers, correlating with methanogenesis. Although reactive-oxygen-species defense mechanisms were widespread, Asgardarchaeota lacked aerobic respiration. These results support the idea that Asgard archaea engaged primarily in syntrophic interactions with sulfate-reducers under early-Earth-like conditions. ### Competing Interest Statement The authors have declared no competing interest. European Research Council, https://ror.org/0472cxd90, 101141745, 787904 Agence Nationale de la Recherche, ANR-23-CE02-0016-01, ANR-22-CE02-0012 Gordon and Betty Moore Foundation, https://ror.org/006wxqw41, GBMF9739

The newly described microbe represents a world of parasitic, intercellular biodiversity only beginning to be revealed by genome sequencing.

Abstract. The topologies of gene trees are broadly used to infer horizontal gene transfer events and characterize the potential donor and acceptor partners

How did life begin, and why does it matter? Scientists are tracing early microbial life—from LUCA to multicellularity—to unlock insights for biotech, climate science and even space exploration.