Tag

Eukaryogenesis

All articles tagged with #eukaryogenesis

science1 day ago•6 min saved

Shark Bay Microbes Illuminate the Birth of Complex Life

Scientists studying Shark Bay’s stromatolites report that an Asgard archaeon named Nerearchaeum marumarumayae and a sulfate-reducing bacterium may have cooperated early in life’s history. DNA sequencing, AI protein modeling, and high-resolution electron cryotomography showing nanotube connections suggest a possible precursor to the first eukaryotic cells, offering a living glimpse into how complex life may have originated. The work also honors Indigenous Malgana language in naming the microbe and highlights the cultural and environmental significance of Gathaagudu (Shark Bay).

via ScienceAlert|

#asgard-archaea #eukaryogenesis #microbial-mats

science1 month ago•7 min saved

Ancient Asgard Microbes May Reveal How Oxygen Enabled Complex Life

Genome analyses reveal oxygen-tolerant Asgard archaea in shallow coastal sediments, suggesting some ancient ancestors used oxygen before merging with bacteria to form eukaryotes, strengthening the link between rising Earth oxygen and the origin of complex life.

via CNN|

#asgard-archaea #eukaryogenesis #great-oxidation-event

science1 month ago•1 min saved

Transitional Microbes Point the Way to Complex Cell Origins

A wave of new studies identifies rare transitional microbes, such as Lokiarchaeum ossiferum, that bridge simple cells and complex eukaryotic cells, offering clues to how cells with nuclei and mitochondria evolved about two billion years ago.

via The New York Times|

#cell-biology #endosymbiosis #eukaryogenesis

science2 months ago•62 min saved

Asgard archaea dominate early eukaryotic evolution, mitochondria arrive later

A comprehensive phylogenomic analysis shows Asgard archaea contributed the majority of core eukaryotic genes traced to LECA, with Alphaproteobacteria providing mainly mitochondrial-related components and energy metabolism; other bacteria contributed sporadically without clear patterns. This supports a model where key eukaryotic features—cytoskeleton and endomembrane system—evolved in the Asgard lineage before LECA, with mitochondria acquired later and additional bacterial genes entering gradually via HGT. The study uses soft-core pangenomes and constrained trees to minimize late HGT and test origins, though conclusions depend on the current sampling of Asgard and bacterial genomes.

via Nature|

#asgard-archaea #eukaryogenesis #horizontal-gene-transfer

biology4 months ago•51 min saved

Revealing the Ancient Origins and Evolution of Complex Life on Earth

The article uses molecular clock analyses of gene duplications to establish a timeline for eukaryotic cell evolution, suggesting that key features like the nucleus, cytoskeleton, and endomembrane system developed before mitochondrial endosymbiosis, with the divergence of eukaryotic lineages occurring around 1.8 billion years ago.

via Nature|

#biology #eukaryogenesis #eukaryotes

science3 years ago•5 min saved

Asgard Cells Reveal Early Signs of Complexity in Life.

The study of Asgard archaea, a group of microbes that may be the closest living relatives of eukaryotes, is shedding light on the origins of complex life. Researchers have cultivated two species of Loki, a type of Asgard archaea, and found that they have tentacle-like filaments made of a protein called Lokiactin, which closely resembles the actin used by eukaryotic cells to build supportive cytoskeletons. This adds plausibility to the inside-out model of eukaryogenesis, which proposes that the first eukaryotes were born after a simple ancestral cell extended protrusions past its cell walls and closed around a symbiotic bacterium, turning it into a proto-mitochondrion.

via Quanta Magazine|

#asgard-archaea #eukaryogenesis #loki-organism