Archaea with eukaryotic tendencies

Eukaryotic cells are so very different from prokaryotes that understanding eukaryote origins and ancestry has been a puzzle. Genetic work places archaea closer than bacteria to eukaryotes, but biochemically and morphologically, archaea are closer to bacteria than to eukaryotes. But now Thijs Ettema and colleagues have identified archaea ? from a core sample from the Loki’s Castle hydrothermal active venting site ? that fit the bill as a genomic ‘starter-kit’ to support the increase in the cellular and genomic complexity that is characteristic of eukaryotes. This novel archaeal group, named Lokiarchaeota, is an immediate sister group of eukaryotes in phylogenetic analyses and has a repertoire of proteins otherwise characteristic of eukaryotes.