A Eukaryote without a Mitochondrial Organelle

Karnkowska et al. overturn the paradigm that eukaryotes must have mitochondria.
Their genomic investigation of the anaerobic microbial eukaryote Monocercomonoides sp. reveals a complete lack of mitochondrial organelle and functions. The complete absence of mitochondria is a secondary loss, not an ancestral feature. The essential mitochondrial ISC pathway, was replaced by a laterally acquired bacterial SUF pathway.

Karnkowska et al., 2016, Current Biology 26, 1–11