According to a new study Candidatus Nanohaloarchaeum AntarcticusThe DPANN archaeon, which lives in a highly saline Antarctic lake called Deep Lake, behaves like a parasitic predator, rapidly killing its host. Harolblum Luxpro Fundy.

“Archaea are one of three lineages of life, along with bacteria and eukaryotes (organisms whose cells have a membrane-enclosed nucleus, such as plants and animals),” said Dr Yan Liao, a microbiologist at the University of Technology Sydney.

“They are widespread and play a vital role in supporting Earth's ecosystems.”

“Compared to other lineages, archaea are less studied and understood. However, they provide clues about the evolution of life on Earth and the possible existence of life on other planets.”

“Its unique biochemistry also holds promising applications in biotechnology and bioremediation.”

“They have been found breeding in highly acidic boiling hot springs, deep-sea hydrothermal vents with temperatures well over 100 degrees, highly saline waters like the Dead Sea, and even in Antarctica.”

Candidatus Nanohaloarchaeum antarcticus was collected from a cold, saline, deep lake in Antarctica by Professor Riccardo Cavicchioli of the University of New South Wales.

This species belongs to a group called DPANN archaea, which are much smaller than other archaea, have very small genomes and limited metabolic capabilities.

Studies have revealed that they depend on host microorganisms, particularly other archaea, for survival.

“This is the first time this aggressive behaviour has been observed in archaea,” said Dr Joshua Hamm, a microbiologist at the Royal Netherlands Institute for Marine Research.

“In many ways, its activity resembles some viruses, leading us to reassess its ecological role in the Antarctic environment.”

DPANN archaea have rarely been cultivated in the laboratory, and the authors developed novel techniques, including unique sample staining, intravital fluorescence microscopy, and electron microscopy, to visualize the interior of host cells and follow the interactions between DPANN archaea and their hosts.

They stained the host archaea. Harolblum Luxpro Fundyand Candidatus Nanohaloarchaeum antarcticus, which has a non-cytotoxic dye that glows in various colors when exposed to laser light.

“This makes it possible to watch organisms together over long periods of time and identify cells by color,” Dr Liao said.

“We observed how the DPANN parasite attached and migrated inside the host cell, causing the host cell to lyse and burst.”

“Predators play a vital role in ecosystems because they not only provide food for themselves by killing their hosts, but also make the remains of the host's cells available as food for other organisms,” said Dr Ian Duggin, a microbiologist at the University of Technology Sydney.

“This allows other microbes to proliferate and prevents the host organism from storing nutrients.”

“The DPANN archaea we studied appear to play a much more important role in ecosystems than has been realized.”

“The parasitic or infectious lifestyle of these archaea may be common.”

of result Published in a journal Nature Communications.

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JN Ham others2024. Parasitic life of archaeal symbionts. Nat Community 15, 6449; doi: 10.1038/s41467-024-49962-y