Wikipedia

Opisthokont

Theopisthokonts(fromAncient Greekὀπίσθιος(opísthios)'rear, posterior' andκοντός(kontós)'pole, i.e.flagellum') are a broad group ofeukaryotes,including both theanimalandfunguskingdoms.[5]The opisthokonts, previously called the "Fungi/Metazoa group",[6]are generally recognized as aclade.Opisthokonts together withApusomonadidaandBreviatacomprise the larger cladeObazoa.[7][8][9][10][11]

Opisthokont
Temporal range:1010–0 Ma[1]
Clockwise, from top left:Abeoforma whisleri(Mesomycetozoea);Amanita muscaria(Fungi);Desmarella moniliformis(Choanoflagellatea);bonnet macaque(Metazoa);Nuclearia thermophila(Nucleariida);Ministeria vibrans(Filasterea)
Scientific classificationEdit this classification
Domain: Eukaryota
Clade: Amorphea
Clade: Obazoa
(unranked): Opisthokonta
Copeland1956,[2]emend.Cavalier-Smith1987,[3]emend.Adlet al., 2005[4]
Subgroups

Flagella and other characteristics

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A common characteristic of opisthokonts is thatflagellatecells, such as thespermof most animals and thesporesof thechytridfungi,propel themselves with a singleposteriorflagellum. It is this feature that gives the group its name. In contrast, flagellate cells in other eukaryote groups propel themselves withone or moreanteriorflagella.Flagellate cells however have been secondarily lost in some opisthokont groups, including most of the fungi.[7]

Opisthokont characteristics include synthesis of extracellularchitinin exoskeleton, cyst/spore wall, or cell wall of filamentous growth and hyphae; the extracellular digestion of substrates with osmotrophic absorption of nutrients; and other cell biosynthetic and metabolic pathways. Genera at the base of each clade are amoeboid andphagotrophic.[12]

History

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The close relationship between animals and fungi was suggested byThomas Cavalier-Smithin 1987,[3]who used the informal name opisthokonta (the formal name has been used for thechytridsbyCopelandin 1956), and was supported by later genetic studies.[13]

Early phylogenies placed fungi near theplantsand other groups that havemitochondriawith flatcristae,but this character varies. More recently, it has been said that holozoa (animals) and holomycota (fungi) are much more closely related to each other than either is to plants, because opisthokonts have a triple fusion ofcarbamoyl phosphate synthetase,dihydroorotase,andaspartate carbamoyltransferasethat is not present in plants, and plants have a fusion ofthymidylate synthaseanddihydrofolate reductasenot present in the opisthokonts. Animals and fungi are also more closely related to amoebas than to plants, and plants are more closely related to theSAR supergroupof protists than to animals or fungi.[citation needed]Animals and fungi are bothheterotrophs,unlike plants, and while fungi aresessilelike plants, there are also sessile animals.

Cavalier-Smith and Stechmann argue that the uniciliate eukaryotes such as opisthokonts andAmoebozoa,collectively calledunikonts,split off from the otherbiciliateeukaryotes, calledbikonts,shortly after theyevolved.[14]

Taxonomy

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Opisthokonts are divided intoHolomycotaor Nucletmycea (fungi and all organisms more closely related to fungi than to animals) andHolozoa(animals and all organisms more closely related to animals than to fungi); no opisthokonts basal to the Holomycota/Holozoa split have yet been identified.[citation needed]The Opisthokonts was largely resolved by Torriella et al.[15]Holomycota and Holozoa are composed of the following groups.[citation needed]

Phylogeny

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The followingphylogenetic treeindicates the evolutionary relationships between the different opisthokont lineages, and the time divergence of the clades in millions of years ago (Mya).[17][18][19]

Amorphea
1500 Mya
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References

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  1. ^Loron, Corentin C.; François, Camille; Rainbird, Robert H.; Turner, Elizabeth C.; Borensztajn, Stephan; Javaux, Emmanuelle J. (June 2019). "Early fungi from the Proterozoic era in Arctic Canada".Nature.570(7760): 232–235.Bibcode:2019Natur.570..232L.doi:10.1038/s41586-019-1217-0.PMID31118507.S2CID162180486.
  2. ^The Classification of Lower Organisms.Palo Alto: Pacific Books. 1956.OCLC477890.
  3. ^abRayner, Alan D. M., ed. (1987). "The origin of fungi and pseudofungi".Evolutionary biology of Fungi.Cambridge: Cambridge University Press. pp. 339–353.ISBN0-521-33050-5.
  4. ^Adl, Sina M.; Simpson, Alastair G. B.; Farmer, Mark A.; Andersen, Robert A.; Anderson, O. Roger; Barta, John R.; et al. (September–October 2005)."The new higher level classification of eukaryotes with emphasis on the taxonomy of protists".The Journal of Eukaryotic Microbiology.52(5): 399–451.doi:10.1111/j.1550-7408.2005.00053.x.PMID16248873.
  5. ^Shalchian-Tabrizi K, Minge MA, Espelund M, Orr R, Ruden T, Jakobsen KS, Cavalier-Smith T (May 2008). Aramayo R (ed.)."Multigene phylogeny of choanozoa and the origin of animals".PLOS ONE.3(5): e2098.Bibcode:2008PLoSO...3.2098S.doi:10.1371/journal.pone.0002098.PMC2346548.PMID18461162.
  6. ^"Fungi/Metazoa group".UniProt.Archived fromthe originalon 17 February 2009.Retrieved2009-03-08.
  7. ^abSteenkamp ET, Wright J, Baldauf SL (January 2006)."The protistan origins of animals and fungi".Molecular Biology and Evolution.23(1): 93–106.doi:10.1093/molbev/msj011.PMID16151185.
  8. ^Huang, Jinling; Xu, Ying; Gogarten, Johann Peter (November 2005)."The presence of a haloarchaeal type tyrosyl-tRNA synthetase marks the opisthokonts as monophyletic".Molecular Biology and Evolution.22(11): 2142–2146.doi:10.1093/molbev/msi221.PMID16049196.
  9. ^Parfrey LW,Barbero E, Lasser E, Dunthorn M, Bhattacharya D, Patterson DJ, Katz LA (December 2006)."Evaluating support for the current classification of eukaryotic diversity".PLOS Genetics.2(12): e220.doi:10.1371/journal.pgen.0020220.PMC1713255.PMID17194223.
  10. ^Torruella, G.; Derelle, R.; Paps, J.; Lang, B. F.; Roger, A. J.; Shalchian-Tabrizi, K.; Ruiz-Trillo, I. (February 2012)."Phylogenetic relationships within the Opisthokonta based on phylogenomic analyses of conserved single-copy protein domains".Molecular Biology and Evolution.29(2): 531–544.doi:10.1093/molbev/msr185.PMC3350318.PMID21771718.
  11. ^Eme, L.; Sharpe, S. C.; Brown, M. W.; Roger, A. J. (August 2014)."On the age of eukaryotes: evaluating evidence from fossils and molecular clocks".Cold Spring Harbor Perspectives in Biology.6(8): a016139.doi:10.1101/cshperspect.a016139.PMC4107988.PMID25085908.
  12. ^Adl, Sina M.; Bass, David; Lane, Christopher E.; Lukeš, Julius; Schoch, Conrad L.; Smirnov, Alexey; et al. (January 2019)."Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes".The Journal of Eukaryotic Microbiology.66(1): 4–119.doi:10.1111/jeu.12691.PMC6492006.PMID30257078.
  13. ^Wainright PO, Hinkle G, Sogin ML, Stickel SK (April 1993). "Monophyletic origins of the metazoa: an evolutionary link with fungi".Science.260(5106): 340–342.Bibcode:1993Sci...260..340W.doi:10.1126/science.8469985.PMID8469985.S2CID27373608.
  14. ^Stechmann, Alexandra;Cavalier-Smith, Thomas(July 2002). "Rooting the eukaryote tree by using a derived gene fusion".Science.297(5578): 89–91.Bibcode:2002Sci...297...89S.doi:10.1126/science.1071196.PMID12098695.S2CID21064445.
  15. ^Torruella, Guifré; De Mendoza, Alex; Grau-Bové, Xavier; Antó, Meritxell; Chaplin, Mark A.; Del Campo, Javier; et al. (September 2015)."Phylogenomics Reveals Convergent Evolution of Lifestyles in Close Relatives of Animals and Fungi".Current Biology.25(18): 2404–2410.doi:10.1016/j.cub.2015.07.053.PMID26365255.
  16. ^Brown, M. W.; Spiegel, F. W.; Silberman, J. D. (December 2009)."Phylogeny of the" forgotten "cellular slime mold, Fonticula alba, reveals a key evolutionary branch within Opisthokonta".Molecular Biology and Evolution.26(12): 2699–2709.doi:10.1093/molbev/msp185.PMID19692665.
  17. ^Tedersoo, Leho; Sánchez-Ramírez, Santiago; Kõljalg, Urmas; Bahram, Mohammad; Döring, Markus; Schigel, Dmitry; et al. (2018)."High-level classification of the Fungi and a tool for evolutionary ecological analyses".Fungal Diversity.90(1): 135–159.doi:10.1007/s13225-018-0401-0.ISSN1560-2745.
  18. ^Galindo, Luis Javier; Torruella, Guifré; López-García, Purificación; Ciobanu, Maria; Gutiérrez-Preciado, Ana; Karpov, Sergey A.; Moreira, David (June 2023). "Phylogenomics Supports the Monophyly of Aphelids and Fungi and Identifies New Molecular Synapomorphies".Systematic Biology.72(3): 505–515.doi:10.1093/sysbio/syac054.PMID35900180.
  19. ^Tikhonenkov, Denis V.; Mikhailov, Kirill V.; Hehenberger, Elisabeth; Karpov, Sergei A.; Prokina, Kristina I.; Esaulov, Anton S.; et al. (November 2020)."New Lineage of Microbial Predators Adds Complexity to Reconstructing the Evolutionary Origin of Animals".Current Biology.30(22): 4500–4509.e5.doi:10.1016/j.cub.2020.08.061.PMID32976804.
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