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Opisthokont

 
Wikipedia: Opisthokont
Opisthokont
Fossil range: Neoproterozoic - Recent
A human holding a mushroom; both are opisthokonts, unlike the trees behind them
Scientific classification
Domain: Eukaryota

The opisthokonts (Greek: ὀπίσθω- (opisthō-) = "rear, posterior" + κοντός (kontos) = "pole" i.e. flagellum) are a broad group of eukaryotes, including both the animal and fungus kingdoms,[1] together with the organisms which were previously grouped in the paraphyletic phylum Choanozoa of the protist "kingdom". Both genetic and ultrastructural studies strongly support that opisthokonts form a monophyletic group.

Many protists are now considered opisthokonts, though should not be substituted for a taxonomic report.[2]

"Opisthokonta" and "Fungi/Metazoa group" are sometimes considered synonymous.[3]

Contents

Flagella

One common characteristic is that flagellate cells, such as most animal sperm and chytrid spores, propel themselves with a single posterior flagellum. This gives the groups its name.

In contrast, flagellate cells in other eukaryote groups propel themselves with one or more anterior flagella.

History

The close relationship between animals and fungi was suggested by Cavalier-Smith in 1987,[4] who used the informal name opisthokonta (the formal name has been used for the chytrids), and was confirmed by later genetic studies.[5]

Early phylogenies placed them near the plants and other groups that have mitochondria with flat cristae, but this character varies.

Cavalier-Smith and Stechmann[6] argue that the uniciliate eukaryotes such as opisthokonts and Amoebozoa, collectively called unikonts, split off from the other biciliate eukaryotes, called bikonts, shortly after they evolved.

Taxonomy

Eukaryota tree


Plantae



Chromalveolata




                       

Amoebozoa


Opisthokonts 


Choanozoa



Animalia





Nucleariids



Fungi





The great kingdoms and their stem groups.[7]



References

  1. ^ Shalchian-Tabrizi K, Minge MA, Espelund M, et al. (2008). "Multigene phylogeny of choanozoa and the origin of animals". PLoS ONE 3 (5): e2098. doi:10.1371/journal.pone.0002098. PMID 18461162. PMC 2346548. http://www.plosone.org/article/info:doi/10.1371/journal.pone.0002098. 
  2. ^ Steenkamp ET, Wright J, Baldauf SL (January 2006). "The protistan origins of animals and fungi". Mol. Biol. Evol. 23 (1): 93–106. doi:10.1093/molbev/msj011. PMID 16151185. http://mbe.oxfordjournals.org/cgi/pmidlookup?view=long&pmid=16151185. 
  3. ^ "Fungi/Metazoa group". http://www.uniprot.org/taxonomy/33154. Retrieved 2009-03-08. 
  4. ^ Cavalier-Smith, T. (1987). "The origin of fungi and pseudofungi". in Rayner, Alan D. M. (ed.). Evolutionary biology of Fungi. Cambridge: Cambridge Univ. Press. pp. 339–353. ISBN 0-521-33050-5. 
  5. ^ Wainright PO, Hinkle G, Sogin ML, Stickel SK (April 1993). "Monophyletic origins of the metazoa: an evolutionary link with fungi". Science (journal) 260 (5106): 340–2. PMID 8469985. http://www.sciencemag.org/cgi/pmidlookup?view=long&pmid=8469985. 
  6. ^ Stechmann, A.; Cavalier-Smith, T. (2002). "Rooting the eukaryote tree by using a derived gene fusion". Science 297: 89–91. doi:10.1126/science.1071196. 
  7. ^ Phylogeny based on:
    • Eichinger, L.; Pachebat, J.A.; Glöckner, G.; Rajandream, M.A.; Sucgang, R.; Berriman, M.; Song, J.; Olsen, R.; Szafranski, K.; Xu, Q.; Others, (2005). "The genome of the social amoeba Dictyostelium discoideum". Nature 435 (7038): 43-57. doi:10.1038/nature03481. 
    • Steenkamp, E.T.; Wright, J.; Baldauf, S.L. (2006). "The Protistan Origins of Animals and Fungi". Molecular Biology and Evolution 23 (1): 93-106. doi:10.1093/molbev/msj011. 

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Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Opisthokont" Read more