A microorganism found on the Costa Brava expands the tree of evolution

BarcelonaWithin mammals there are various orders, such as primates, to which humans belong; cetaceans, such as whales or dolphins, or carnivores. Now, a team from the Institute of Evolutionary Biology (IBE) has discovered a new species of microorganism in Blanes, in the Selva region. This is a finding that, while maintaining proportions, could be equated to the discovery of a new order within mammals, as it adds a new branch to the evolutionary tree of this group. In this case, however, we are talking about amoebas, unicellular microorganisms that maintain a dynamically stable shape, can have more than one nucleus, and move by forming "false feet or pseudopods through extensions of the cell membrane.

The researchers at IBE have located in the waters of Blanes an amoeba of "unknown" lineage and with new behaviors, which they have named "Bipolarization is only observed during division in eukaryotic cells, a key point in many studies on cancerous processes. It has similarities with cytoplasmic bridges between animal cells and could be a useful comparison for studying them," states the first author of the study and researcher, Àlex Gàlvez-Morante. This behavior can be induced in the laboratory by lowering the amount of nutrients in the culture, a fact that reinforces the theory that the microorganism has an exploratory function.

New order

DNA analyses reveal that A. explorator does not belong to any known amoeba lineage, but is a new order that had remained hidden in environmental samples. In phylogenetic terms, researchers state, the magnitude of the discovery would be comparable to identifying a new order within mammals, at the taxonomic level of primates or cetaceans.

This amoeba belongs to the amebozoids, a sister group to the lineage that gave rise to animals and fungi. "This new order is so far removed from the rest of amebozoids that it leads us to hypothesize about the existence of numerous amoeba species that we do not know," remarks the principal investigator of the Laboratory of Biology and Ecology of Abundant Protists at IBE, Daniel Richter. In this regard, Catalan scientists believe it could contain clues about the origin of many eukaryotic species. "The behavior of A. explorator, however, offers a glimpse into the future of research. We will have to continue exploring," concludes Richter.