2003/03/25 by V. V. Emelyanov · 3 citations
Biochemistry, Genetics and Molecular Biology · Agricultural and Biological Sciences · #Genomics and Phylogenetic Studies #Protist diversity and phylogeny #Legume Nitrogen Fixing Symbiosis
paper · pdf · doi:10.1046/j.1432-1033.2003.03499.x
openalex publication_date 2003/03/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/15
Phylogenetic evidence is presented that primitively amitochondriate eukaryotes containing the nucleus, cytoskeleton, and endomembrane system may have never existed. Instead, the primary host for the mitochondrial progenitor may have been a chimeric prokaryote, created by fusion between an archaebacterium and a eubacterium, in which eubacterial energy metabolism (glycolysis and fermentation) was retained. A Rickettsia-like intracellular symbiont, suggested to be the last common ancestor of the family Rickettsiaceae and mitochondria, may have penetrated such a host (pro-eukaryote), surrounded by a single membrane, due to tightly membrane-associated phospholipase activity, as do present-day rickettsiae. The relatively rapid evolutionary conversion of the invader into an organelle may have occurred in a safe milieu via numerous, often dramatic, changes involving both partners, which resulted in successful coupling of the host glycolysis and the symbiont respiration. Establishment of a potent energy-generating organelle made it possible, through rapid dramatic changes, to develop genuine eukaryotic elements. Such sequential, or converging, global events could fill the gap between prokaryotes and eukaryotes known as major evolutionary discontinuity.