title: Organelle origins: energy-producing symbionts in early eukaryotes?.
abstract: The discovery that Trichomonas vaginalis, an early diverging protist that lacks mitochondria but has energy-producing hydrogenosomes, makes bacterial-like heat shock proteins suggests that symbionts ancestral to mitochondria and hydrogenosomes were present at early stages of eukaryote evolution.
authors.affiliation: Bay-Paul Center for Comparative Molecular Biology and Evolution Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Sogin
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004734:Energy Metabolism; D005057:Eukaryotic Cells; D017125:Genes, Protozoan; D008928:Mitochondria / Q000502:physiology; D015388:Organelles / Q000502:physiology*; D013559:Symbiosis; D014246:Trichomonas vaginalis / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure