Surprise from the Deep Ocean

Archaea belong together with Bacteria to the first organisms that emerged on Earth. These microorganisms existed hundreds of millions of years before the more complex cell structures of Eukaryotes developed that gave rise to macroscopic life, i.e. plants and animals. An international team of researchers from Uppsala (Sweden), Bergen (Norway) and Vienna (Austria), has found a novel group of Archaea in deep ocean sediments, who are the closest direct relatives of the eukaryotic lineage. Their genome shows an unexpected similarity to those of Eukaryotes. The results of this study appear in the current issue of the journal "Nature". How did the first complex eukaryotic cells with their organelles develop from simple prokaryotes, i.e. bacteria or archaea? This is a highly debated topic in evolutionary research but the question remains largely unresolved. Genomic research has shown that the organelles delivering energy in eukaryotic cells stem from an early bacterial symbiont.