title: Eukaryotic origins: How and when was the mitochondrion acquired?
abstract: Comparative genomics has revealed that the last eukaryotic common ancestor possessed the hallmark cellular architecture of modern eukaryotes. However, the remarkable success of such analyses has created a dilemma. If key eukaryotic features are ancestral to this group, then establishing the relative timing of their origins becomes difficult. In discussions of eukaryote origins, special significance has been placed on the timing of mitochondrial acquisition. In one view, mitochondrial acquisition was the trigger for eukaryogenesis. Others argue that development of phagocytosis was a prerequisite to acquisition. Results from comparative genomics and molecular phylogeny are often invoked to support one or the other scenario. We show here that the associations between specific cell biological models of eukaryogenesis and evolutionary genomic data are not as strong as many suppose. Disentangling these eliminates many of the arguments that polarize current debate.
authors.affiliation: School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand Biomolecular Interaction Centre, University of Canterbury, Christchurch 8140, New Zealand Allan Wilson Centre for Molecular Ecology and Evolution, University of Canterbury, Christchurch 8140, New Zealand.
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Poole
authors.affiliation: Institut Pasteur, Unité Biologie Moléculaire du Gene chez les Extrêmophiles, Département de Microbiologie, Paris 75724, France.
authors.forename: Simonetta
authors.initials: S
authors.lastname: Gribaldo
mesh_terms: D005075:Biological Evolution; D056890:Eukaryota / Q000166:cytology*; D008928:Mitochondria / Q000502:physiology*; D008954:Models, Biological; D010587:Phagocytosis / Q000502:physiology*; D010802:Phylogeny; D013559:Symbiosis