This MedLibrary.org supplementary page on Unikonta is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
| Unikonts | ||||
|---|---|---|---|---|
| Scientific classification | ||||
|
||||
| Supergroups | ||||
Unikonts are members of the Unikonta, a taxonomic group proposed by Thomas Cavalier-Smith. The group includes eukaryotic cells with a single flagellum, at least ancestrally. Some research suggests that a unikont was the ancestor of opisthokonts (animals, fungi and related forms) and Amoebozoa, and a bikont (a eukaryotic cell with two flagella) was the ancestor of Archaeplastida (plants and relatives), Excavata, Rhizaria, and Chromalveolata.
The unikonts have a triple-gene fusion that is lacking in the bikonts. The three genes that are fused together in the unikonts but not bacteria or bikonts encode enzymes for synthesis of the pyrimidine nucleotides: carbamoyl phosphate synthase, dihydroorotase, aspartate carbamoyltransferase (Cavalier-Smith 2006). This must have involved a double fusion, a rare pair of events, supporting the shared ancestry of Opisthokonta and Amoebozoa.
The unikonts have a single centriole (Cavalier-Smith, 2002, 2006). Some unikonts have two centrioles but their origins are developmentally different than in the bikonts, indicating convergent evolution (Cavalier-Smith 2006).
References
- Cavalier-Smith, Thomas (2002). "The phagotrophic origin of eukaryotes and phylogenetic classification of Protozoa" (abstract). International Journal of Systematic and Evolutionary Microbiology 52 (2): 297–354. ISSN 1466-5026. PMID 11931142, http://ijs.sgmjournals.org/cgi/content/abstract/52/2/297. Retrieved on 8 June 2007.
- Cavalier-Smith, Thomas (2003). "Protist phylogeny and the high-level classification of Protozoa". European Journal of Protistology 39 (4): 338–348. doi:. ISSN 0932-4739.
- Stechmann, Alexandra; Cavalier-Smith, Thomas (2003). "The root of the eukaryote tree pinpointed". Current Biology 13 (17): R665–R666. doi:. ISSN 0960-9822.
 |
This protist-related article is a stub. You can help Wikipedia by expanding it. |
Wikipedia content modification information:
- This page was last modified on 9 November 2008, at 14:48.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Unikonta".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.