Opisthokont

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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 phylum Choanozoa and Mesomycetozoa of the protist "kingdom". Both genetic and ultrastructural studies strongly support that opisthokonts form a monophyletic group.

Many protists are now considered opisthokonts.[2]

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

Contents

[edit] 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.

[edit] 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.

[edit] Taxonomy

Eukaryota tree


Plantae



Chromalveolata




                       

Amoebozoa


Opisthokonts 


Choanozoa



Animalia





Nucleariids



Fungi





The great kingdoms and their stem groups.[7]



[edit] 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 on 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. 

[edit] External links

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