Asgard archaea study reveals origins of complex cellular movement

Researchers at the University of Vienna have captured live footage of Asgard archaea crawling across surfaces, providing new insights into the evolutionary origins of complex life. The study, published in Nature, reveals that these microorganisms use rapidly growing and retracting protrusions powered by a Lokiactin-based cytoskeleton to move.

Asgard archaea are considered the closest known prokaryotic relatives to eukaryotes, the group of organisms that includes all animals, plants, and fungi. The observed movement is strikingly similar to the cellular mechanics seen in more complex cells, such as amoebae and human immune cells. This suggests that sophisticated actin-driven machinery existed before the emergence of eukaryotic life approximately 2 billion years ago.

To observe these anaerobic organisms alive, the research team developed a specialized oxygen-free microscopy system. This allowed for the monitoring of Candidatus Lokiarchaeum ossiferum and Candidatus Margulisarchaeum peptidophilum, overcoming previous technical barriers that limited observations to static genome sequences or frozen electron-microscope images.