Hydrogenosomes and Symbiosis

Hackstein, J.H.P.; Yarlett, Nigel

doi:10.1007/3-540-28221-1_7

Cited by 6 publications

(3 citation statements)

References 113 publications

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“…However, the paucity of relict methanogenesis or its coenzyme biochemistry requires rejection of methanogens in eukaryotic ancestry. Methanogenesis, like oxygenic photosynthesis, is correlated with secondary acquisition of symbiotic bacteria in anoxic environments (27,28). The absence of primary methanogenesis in anaerobic protists contrasts strikingly with the widespread, if not universal, detection of cytoplasmic sulfidogenesis (17) in all four eukaryotic lineages [protoctists, plants, fungi, and animals including human erythrocytes (16)] consistent with the concept that sulfidogenesis was introduced by the Thermoplasma archaebacterium symbiont (19).…”

Section: Hydrogen Sulfide (H 2 S)-oxygen (O 2 ) Interface Habitatsmentioning

confidence: 67%

“…Many, if not all eubacterial enzymes asserted to derive from relict mitochondria are common to eubacteria. Loss and͞or dedifferentiation of mitochondria in isolated species is well known: the rumen protist Neocallimastix, a chytrid; plagiopylid ciliates with stripped bodies in the cytoplasm; and many sapropel ciliates (27,28). Some fungi (glucose-repressed yeast) and marine worms have dedifferentiated mitochondria interpretable as legacies of local evolution: nearly all fungi and animals are mitochondriates in oxic habitats.…”

Section: Hydrogen Sulfide (H 2 S)-oxygen (O 2 ) Interface Habitatsmentioning

confidence: 99%

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The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon

Margulis

Chapman

Guerrero

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

124

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We develop a symbiogenetic concept of the origin of eukaryotic intracellular motility systems from anaerobic but aerotolerant spirochetes in sulfide-rich environments. The last eukaryotic common ancestors (LECAs) have extant archaeprotist descendants: motile nucleated cells with Embden-Meyerhof glycolysis and substrate-level phosphorylation that lack the ␣-proteobacterial symbiont that became the mitochondrion. Swimming and regulated O 2-tolerance via sulfide oxidation already had been acquired by sulfidogenic wall-less archaebacteria (thermoplasmas) after aerotolerant cytoplasmictubule-containing spirochetes (eubacteria) attached to them. Increasing stability of sulfide-oxidizing͞sulfur-reducing consortia analogous to extant sulfur syntrophies (Thiodendron) led to fusion. The eubacteria-archaebacteria symbiosis became permanent as the nucleus evolved by prokaryotic recombination with membrane hypertrophy, analogous to Gemmata obscuriglobus and other ␦-proteobacteria with membrane-bounded nucleoids. Histone-coated DNA, proteinsynthetic RNAs, amino-acylating, and other enzymes were contributed by the sulfidogen whereas most intracellular motility derives from the spirochete. From this redox syntrophy in anoxic and microoxic Proterozoic habitats LECA evolved. The nucleus originated by recombination of eu-and archaebacterial DNA that remained attached to eubacterial motility structures and became the microtubular cytoskeleton, including the mitotic apparatus. Direct LECA descendants include free-living archaeprotists in anoxic environments: archamoebae, metamonads, parabasalids, and some mammalian symbionts with mitosomes. LECA later acquired the fully aerobic Krebs cycle-oxidative phosphorylation-mitochondrial metabolism by integration of the protomitochondrion, a third ␣-proteobacterial symbiont from which the ancestors to most protoctists, all fungi, plants, and animals evolved. Secondarily anaerobic eukaryotes descended from LECA after integration of this oxygen-respiring eubacterium. Explanatory power and experimental predictions for molecular biology of the LECA concept are stated.karyomastigont ͉ kinetosome-centriole ͉ mitotic apparatus ͉ nucleus origin ͉ Thiodendron

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Section: Hydrogen Sulfide (H 2 S)-oxygen (O 2 ) Interface Habitatsmentioning

confidence: 67%

Section: Hydrogen Sulfide (H 2 S)-oxygen (O 2 ) Interface Habitatsmentioning

confidence: 99%

The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon

Margulis

Chapman

Guerrero

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

124

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“…But the hydrogenases of Spironucleus, Giardia and Entamoeba histolytica are cytosolic; presumably they retained enzymes from the eubacterial ancestor (for example, the sulphur syntrophic Perfil'ieva). Anaerobic chytrids, even in the same genus, differ markedly (Neocallimastix ovalis versus Neocallimastix frontalis), confirming hydrogenase-hydrogenosome polyphyly 19 . The origin of Fe-Fe hydrogenases that are incapable of generating hydrogen gas in 'crown taxa eukaryotes' (animals, plants and fungi) noted by Meyer 17 is implied by the data that de Duve discussed.…”

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confidence: 87%

Semes for analysis of evolution: de Duve's peroxisomes and Meyer's hydrogenases in the sulphurous Proterozoic eon

2007

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Trichomonads

Yarlett

2021

Encyclopedia of Life Sciences

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Trichomonads are a diverse collection of flagellate protozoa that are grouped in the phylum Parabasalia identified by the presence of an intracellular fibrous band composed of microtubules termed the axostyle. They encompass free‐living, symbiotic and parasitic representatives, with representatives of the latter group being the most studied, for example the human sexually transmitted parasite Trichomonas vaginalis , the cattle sexually transmitted parasite Tritrichomonas foetus , and the Colombian and galliform bird pathogen Trichomonas gallinae . With the exception of Monocercomonoides sp. they all contain a divergent mitochondrion‐like organelle, termed the hydrogenosome which is considered to have evolved due to the secondary adaptation to low oxygen environments. Key Concepts Trichomonads are in the clade Metamonada, a diverse group of anaerobic or microaerophilic protists that possess modified mitochondria lacking cytochromes, a functional TCA cycle and a genome. The Parabasalia are a phylum within the Metamoada which include all cells with two or more striated parabasal fibres connecting the Golgi apparatus to the ciliary apparatus (parabasal apparatus). The parabasalia are further divided into eight orders including the Trichomonadida, Tritrichomonadida and the Hypotrichomonadida; which are distinguished by the number of flagella, type of karyomastigont, axoneme, undulating membrane and costa. Trichomonads have adapted to an anaerobic metabolism and therefore lack an oxidative metabolism and classic mitochondria, instead of possessing hydrogenosomes. Hydrogenosomes have retained many features of classic mitochondria, including chaperonins; heat shock proteins; outer (TOM 40) and inner membrane (TIM17/22/23) components required for protein import and metabolite exchange; mitochondrial paralogs that are responsible for Fe–S protein assembly; trichomonad nuclear valyl tRNA synthetase gene has a high degree of sequence homology with the mitochondrial valyl tRNA synthetases.

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Hydrogenosomes and Symbiosis

Cited by 6 publications

References 113 publications

The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon

The last eukaryotic common ancestor (LECA): Acquisition of cytoskeletal motility from aerotolerant spirochetes in the Proterozoic Eon

Semes for analysis of evolution: de Duve's peroxisomes and Meyer's hydrogenases in the sulphurous Proterozoic eon

Trichomonads

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