Asgard Archaea Use Actin Proteins to Crawl on Surfaces
The finding suggests the cellular machinery for complex movement evolved well before the emergence of modern complex life.
Updated on Oct. 30, 2026 in Life Sciences
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Researchers have observed Asgard archaea microbes, including Lokiarchaeum ossiferum, using actin-based arms to crawl across glass surfaces. This behavior provides evidence that these ancient organisms utilize the same protein-driven mechanics found in the complex cells of higher life forms.
Why it matters
The study suggests that the fundamental machinery for complex cellular motion evolved long before the emergence of modern complex life. By linking actin protein activity to physical movement in archaea, researchers are clarifying the evolutionary origins of eukaryotic cells.
The microbes maintain a crawl speed of 1.6 micrometers a minute, while arm growth rates reach up to 4.8 micrometers a minute in Margulisarchaeum peptidophilum. Motion is halted by 50 nanograms per milliliter of swinholide A, an actin-blocking agent that confirms actin's role in the process.
The players
University of Vienna
A research institution specializing in microbial evolutionary biology and the lead lab for this observation.
JAMSTEC
The Japan Agency for Marine-Earth Science and Technology, which provided the environment for cultivating the Margulisarchaeum peptidophilum species.
The details
Asgard archaea use actin—a protein essential for muscle contraction and cell shape in complex organisms—to extend thin arms up to 15 micrometers long. These appendages branch and retract to facilitate locomotion while the microbe simultaneously redistributes its outer membrane to alter its overall body shape. Researchers confirmed this relies on actin by applying swinholide A, which inhibits actin polymerization, thereby forcing the microbes to stop both arm growth and physical movement.
Timeline
2 billion years ago: The period when complex cells are thought to have first formed via archaea-bacterium symbiosis.
The Tech Race
This finding builds on the long-standing effort to map the transition from simple archaea to complex eukaryotes. It establishes a functional link between Asgard archaea and the cytoskeletal mechanics that eventually enabled multicellular life.
While this research occurs at a fundamental level, it provides the core scientific data required to model how cells manage motility at the microscopic scale. These findings serve as a baseline for future synthetic biology projects that aim to replicate protein-based movement in artificial cellular systems.
The takeaway
The study confirms that archaea possess the necessary protein toolkit for complex movement, closing a key gap in the evolutionary history of life. Researchers are now looking to identify how membrane redistribution and actin polymerization interact to drive these specific cellular shape changes.
Further reading
Explore more about Life Sciences to understand the evolutionary mechanisms governing cellular development.
Source note: This article includes information reported by Earth.
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