Ancient microbes, whose existence preceded the appearance of nucleus-bearing cells on Earth, may have been able tokeep
According to a new report published in the journal Nature, researchers have grown an organism called Lokiarchaeum ossiferum, which belongs to named after the abode of the gods in Norse mythology, the Asgardian archaea are believed by some scientists to be the closest evolutionary relatives of eukaryotes.These cells pack their DNA into a protective bubble called the nucleus.
The cells of the Asgardian archaea lack a nucleus, but havea set of genes and proteins previously thought to be unique to eukaryotes. Researchers have many theories about how the Asgard obtained primitive nuclei and thus gave birth to the first complex cells. According to one of the most popular, eukaryotes arose as a result of the merger of the Asgardian archaea with a bacterium. These, in turn, gave rise to plants, animals, and humans—all complex life.
Eukaryotes (including animals, plants and fungi) may have arisen from the fusion of an Asgardian archaea with a bacterium. Credit: Florian Wohlweber, ETH Zürich
In 2020 research groupJapan reported that after 12 years of work, they successfully raised Asgard in the laboratory. Namely, Prometheoarchaeum syntrophicum, an Asgardian named after the Greek god Prometheus. But they could not see the details of their internal body structure. Now other scientists have grown L. ossiferum and taken pictures of its insides. In particular, they found some semblance of a skeleton.
“It took six long years to getstable and highly enriched culture. But this experience will be useful for other biochemical studies, as well as for cultivating other Asgardian archaea,” the scientists write.
Cryo-electron tomography helped scientistsgain insight into the cellular structure of a newly cultured Asgardian archaeon shown here. Especially notable are the extensive filaments of actin cytoskeleton (orange) in the cell bodies, as well as the unique cell wall (blue). Credit: Margot Riggi, Animation Lab, University of Utah
Compared to other Asgardians, L.ossiferum grows relatively quickly, doubling its cell number in 7–14 days. In comparison, P. syntrophicum reproduces every 14 to 25 days. At the same time, E. coli (Escherichia coli), for example, multiplies every 20 minutes. Slow growth is one of the factors that makes cultivating ancient microorganisms difficult.
Some scientists believe that the study confirms the hypothesis that the Asgardians are the direct ancestors of eukaryotes, but not all experts are sure of this, writes Science.
Read more:
It turned out how old the water we drink today
17-year-old engineer came up with a magnetless motor: it can be used in electric vehicles
Two planets have been found not far from Earth. Perhaps they are inhabited
Cover: Scanning electron micrograph of a Lokiarchaeum ossiferum cell showing long and complex cellular projections.
Credit: Thiago Rodriguez-Oliveira, University of Vienna