Institutional development · Research, innovation and assessment · Japan
JAMSTEC and Kyoto University team cultures closest archaeal relatives of eukaryotes, in Nature
Researchers from JAMSTEC, Japan's marine science agency, and Kyoto University say they are the first to isolate and grow two Heimdallarchaeia strains, finding simple cell interiors but complex external protrusions used for symbiosis.
Why it matters: Researchers studying the origin of eukaryotes gain two cultured Heimdallarchaeia strains that the team describes as model organisms for testing that origin experimentally.
A team including Hiroyuki Imachi and Masaru K. Nobu of JAMSTEC (Japan Agency for Marine-Earth Science and Technology) and Satoshi Nakagawa of Kyoto University's Graduate School of Agriculture said it had isolated and cultured two strains of Heimdallarchaeia, the archaeal group closest to eukaryotes, for the first time worldwide.
According to the university, the cultured cells showed no complex eukaryote-like internal structures but formed long protrusions and membrane vesicles on their exterior, which they used to attach to and live symbiotically with other microbes.
The strains were anaerobic, but the researchers reported that one could grow with trace oxygen present at the start of culture when oxygen-consuming bacteria were grown alongside it.
The work was published in Nature on 28 October 2026 (London time) and was supported by funders including Japan Society for the Promotion of Science grants, the Moore and Simons foundations, and JST's CREST programme.
Editor’s view
Scott James, Research and Innovation Editor
For researchers working on how eukaryotes arose, the team says the two strains will serve as model organisms, and that further study of their cell structure and symbiosis is expected to clarify how complex eukaryotes emerged from simple archaea.
