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ScienceQuiet 10d · day 12

Scientists culture archaea closest to eukaryotes, revealing origins of complex life

Two newly isolated archaeal strains hint at how cells evolved from simple microbes to complex organisms.

newest coverage 9d agosummary written 9d ago8 pieces NewswiresRedditGoogle News

What to know

  • Scientists isolated and cultured two strains of Heimdallarchaeia, the archaeal lineage closest to eukaryotes, offering first direct look at the physiology of eukaryotes' closest living relatives.
  • The cultured archaea are internally simple, anaerobic, and depend on symbiotic partnerships—suggesting the ancient archaeal ancestor of eukaryotes was similarly structured.
  • Early interactions between the archaeal host and mitochondrial ancestor likely occurred under low-oxygen conditions and involved oxygen detoxification rather than respiration.
  • The findings reshape understanding of eukaryogenesis by showing the transition from simple archaea to complex eukaryotic cells involved a dramatic shift in cell structure and oxygen metabolism.

“Eukaryotes probably evolved from a lineage closely related to members of the archaeal group Asgard archaea, which has now been formally classified as the phylum Promethearchaeota.”

Imachi et al., Research authors · Nature ↗ · Oct 27

Hiroyuki Imachi Research lead, JAMSTECMasaru K. Nobu Research co-lead, JAMSTECSatoshi Nakagawa Researcher, Kyoto University

Scientists culture archaea closest to eukaryotes, revealing origins of complex life
nature.com

How it unfolded 3 developments, newest first · click a bar or a number to jump articlesposts

Peak 4 pieces in 3h at Oct 29, 1 AM; 8 pieces over 12 days (7 articles · 1 post) Oct 27, 7 PM — 2 pieces · 2 articles — Newswires 2Oct 27, 10 PM — quietOct 28, 1 AM — quietOct 28, 4 AM — quietOct 28, 7 AM — quietOct 28, 10 AM — quietOct 28, 1 PM — 1 piece · 1 article — Google News 1Oct 28, 4 PM — quietOct 28, 7 PM — quietOct 28, 10 PM — quietOct 29, 1 AM — 4 pieces · 3 articles · 1 post — Google News 3, Reddit 1Oct 29, 4 AM — quietOct 29, 7 AM — quietOct 29, 10 AM — 1 piece · 1 article — Newswires 1Oct 29, 1 PM — quietOct 29, 4 PM — quietOct 29, 7 PM — quietOct 29, 10 PM — quietOct 30, 1 AM — quietOct 30, 4 AM — quietOct 30, 7 AM — quietOct 30, 10 AM — quietOct 30, 1 PM — quietOct 30, 4 PM — quietOct 30, 7 PM — quietOct 30, 10 PM — quietOct 31, 1 AM — quietOct 31, 4 AM — quietOct 31, 7 AM — quietOct 31, 10 AM — quietOct 31, 1 PM — quietOct 31, 4 PM — quietOct 31, 7 PM — quietOct 31, 10 PM — quietNov 1, 1 AM — quietNov 1, 3 AM — quietNov 1, 6 AM — quietNov 1, 9 AM — quietNov 1, 12 PM — quietNov 1, 3 PM — quietNov 1, 6 PM — quietNov 1, 9 PM — quietNov 2, 12 AM — quietNov 2, 3 AM — quietNov 2, 6 AM — quietNov 2, 9 AM — quietNov 2, 12 PM — quietNov 2, 3 PM — quietNov 2, 6 PM — quietNov 2, 9 PM — quietNov 3, 12 AM — quietNov 3, 3 AM — quietNov 3, 6 AM — quietNov 3, 9 AM — quietNov 3, 12 PM — quietNov 3, 3 PM — quietNov 3, 6 PM — quietNov 3, 9 PM — quietNov 4, 12 AM — quietNov 4, 3 AM — quietNov 4, 6 AM — quietNov 4, 9 AM — quietNov 4, 12 PM — quietNov 4, 3 PM — quietNov 4, 6 PM — quietNov 4, 9 PM — quietNov 5, 12 AM — quietNov 5, 3 AM — quietNov 5, 6 AM — quietNov 5, 9 AM — quietNov 5, 12 PM — quietNov 5, 3 PM — quietNov 5, 6 PM — quietNov 5, 9 PM — quietNov 6, 12 AM — quietNov 6, 3 AM — quietNov 6, 6 AM — quietNov 6, 9 AM — quietNov 6, 12 PM — quietNov 6, 3 PM — quietNov 6, 6 PM — quietNov 6, 9 PM — quietYesterday, 12 AM — quietYesterday, 3 AM — quietYesterday, 6 AM — quietYesterday, 9 AM — quietYesterday, 12 PM — quietYesterday, 3 PM — quietYesterday, 6 PM — quietYesterday, 9 PM — quietToday, 12 AM — quietToday, 3 AM — quietToday, 6 AM — quiet 1–23
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  1. 3

    Findings suggest archaeal ancestor of eukaryotes was anaerobic and structurally simple

    The conservation of anaerobiosis, lack of internal membranes, and membrane protrusions across Promethearchaeota suggests the archaeal ancestor of eukaryotes shared these features. The transition to complex eukaryotic cells likely involved a steep shift in cell structure and physiology from anaerobiosis to aerobiosis, with early archaeal-mitochondrial interactions occurring under low-oxygen conditions.

    “The archaea–eukaryote transition would involve a steep transition in cell structure and physiological shift from anaerobiosis to (facultative) aerobiosis.”
    — Imachi et al.
  2. 1

    HC1 strain possesses aerobic genes but functions only for oxygen detoxification

    Strain HC1 carries genes like cytochrome c oxidase (Cox) associated with aerobic lifestyles, but comparative genomics shows these archaea likely do not respire oxygen. Cox appears to support oxygen detoxification rather than respiration, allowing growth in the presence of aerobes under microoxic conditions.

  3. background

    Study reveals archaea lack internal membrane structures and live anaerobically — The cultured strains are obligately anaerobic, peptide-degrading archaea that produce surface protrusions and vesicles but lack persistent internal membrane structures. Both strains demonstrate behavior focused on cell construction rather than division, contrasting with typical prokaryotes.

  4. 2

    Researchers isolate and culture two archaeal strains closest to eukaryotes

    A team led by Hiroyuki Imachi and Masaru K. Nobu isolated two strains, HC1 and SC1, belonging to Heimdallarchaeia, the archaeal lineage that branches closest to eukaryotes. The isolates were cultivated in pure and mixed cultures with methanogenic partners.

    1. 2 outlets Capturing Closest Archaeal Relatives May Reveal Eukaryote Origins

      first by Mirage News, 10d ago · also The National Tribune

      1 more headline

Also covered reported alongside — the timeline has no entry for these yet

  1. 2 outlets Eukaryotes’ closest relatives are internally simple syntrophic peptidotrophic archaea

    first by Nature, 10d ago · also Nature News

and 1 smaller piece