Neokaryotes

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Neokaryotes
Amoeba proteus.jpg
Amoeba proteus , visible are the contractile vacuole (circular) and the nucleus (somewhat dumbbell-shaped)
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Domain: Eukaryota
(unranked): Orthokaryotes
(unranked): Neokaryotes
Clades

The neokaryotes (Cavalier-Smith 1993) are a proposed eukaryote clade consisting of the unikonts and the bikonts as sister of for instance the Jakobea. It arises because the Euglenozoa, Percolozoa, Tsukubea, and Jakobea are seen in this view as more basal eukaryotes. These four groups, are traditionally grouped together in the Discoba. However, the Discoba may well be paraphyletic as the neokaryotes may have emerged in them. [1]

The group was recovered as a monophyletic group in a later analysis, Al Jewari and Baldauf (2023). [2]

Taxonomy

A proposed cladogram is [3] [4] [5] [6] [7] [8] [9] [10]

Eukaryota

Related Research Articles

<span class="mw-page-title-main">Metamonad</span> Phylum of excavate protists

The metamonads are a large group of flagellate amitochondriate microscopic eukaryotes. Their composition is not entirely settled, but they include the retortamonads, diplomonads, and possibly the parabasalids and oxymonads as well. These four groups are all anaerobic, occurring mostly as symbiotes or parasites of animals, as is the case with Giardia lamblia which causes diarrhea in mammals.

<span class="mw-page-title-main">Amorphea</span> Group including fungi, animals and various protozoa

Amorphea is a taxonomic supergroup that includes the basal Amoebozoa and Obazoa. That latter contains the Opisthokonta, which includes the Fungi, Animals and the Choanomonada, or Choanoflagellates. The taxonomic affinities of the members of this clade were originally described and proposed by Thomas Cavalier-Smith in 2002.

<span class="mw-page-title-main">Ichthyosporea</span> Clade of eukaryote organisms

The Ichthyosporea are a small group of Opisthokonta in Eukaryota, mostly parasites of fish and other animals.

<span class="mw-page-title-main">Corticata</span> Type of plant

Corticata, in the classification of eukaryotes, is a clade suggested by Thomas Cavalier-Smith to encompass the eukaryote supergroups of the following two groups:

<span class="mw-page-title-main">Malawimonadidae</span> Family of protists

Malawimonadidae is a family of unicellular eukaryotes of outsize importance in understanding eukaryote phylogeny.

Micronuclearia is a genus of free-living protozoa containing the single species Micronuclearia podoventralis. While originally thought to be a nucleariid, as reflected in the name, it is now inferred to be a member of the taxon Rigifilida, and to belong to the 'CRuMs' assemblage.

<span class="mw-page-title-main">Loukozoa</span> Proposed taxon

Loukozoa is a proposed taxon used in some classifications of eukaryotes, consisting of the Metamonada and Malawimonadea. Ancyromonads are closely related to this group, as sister of the entire group, or as sister of the Metamonada. Amorphea may have emerged in this grouping, specifically as sister of the Malawimonads.

<span class="mw-page-title-main">Ancyromonadida</span> Group of protists

Ancyromonadida or Planomonadida is a small group of biflagellated protists found in the soil and in aquatic habitats, where they feed on bacteria. Includes freshwater or marine organisms, benthic, dorsoventrally compressed and with two unequal flagellae, each emerging from a separate pocket. The apical anterior flagellum can be very thin or end in the cell membrane, while the posterior flagellum is long and is inserted ventrally or laterally. The cell membrane is supported by a thin single-layered theca and the mitochondrial crests are discoidal/flat.

<span class="mw-page-title-main">Breviatea</span> Group of protists

Breviatea, commonly known as breviate amoebae, are a group of free-living, amitochondriate protists with uncertain phylogenetic position. They are biflagellate, and can live in anaerobic (oxygen-free) environments. They are currently placed in the Obazoa clade. They likely do not possess vinculin proteins. Their metabolism relies on fermentative production of ATP as an adaptation to their low-oxygen environment.

Rigifilida is a clade of non-ciliate phagotrophic eukaryotes. It consists of two genera: Micronuclearia and Rigifila.

Rigifila is a genus of free-living single-celled eukaryotes, or protists, containing the sole species Rigifila ramosa. It is classified within the monotypic family Rigifilidae. Along with Micronucleariidae, it is a member of Rigifilida, an order of basal eukaryotes within the CRuMs clade. It differs from Micronuclearia by having two proteic layers surrounding their cytoplasm instead of a single one, and having more irregular mitochondrial cristae, among other morphological differences.

<span class="mw-page-title-main">Podiata</span> Clade of shelled animals

Podiates are a proposed clade containing the Amorphea and the organisms now assigned to the clade CRuMs. Ancyromonadida does not appear to have emerged in this grouping. Sarcomastigota is a proposed subkingdom that includes all the podiates that are not animals or fungi. Sulcozoa is a proposed phylum within Sarcomastigota that does not include the phyla Amoebozoa (clade) and Choanozoa (paraphyletic), i.e. it includes the proposed subphyla Apusozoa and Varisulca

<span class="mw-page-title-main">Varisulca</span> Proposed phylum of protists

Varisulca was a proposed basal Podiate taxon. It encompassed several lineages of heterotrophic protists, most notably the ancyromonads (planomonads), collodictyonids (diphylleids), rigifilids and mantamonadids. Recent evidence suggests that the latter three are closely related to each other, forming a clade called CRuMs, but that this is unlikely to be specifically related to ancyromonads

Tsukubamonas is a monotypic genus of excavates that contains a single species, Tsukubamonas globosaYabuki et al. 2011. T. globosa is a free-living flagellate that was isolated from a pond in the University of Tsukuba, Japan.

<span class="mw-page-title-main">Aphelida</span> Phylum of fungi

Aphelida is a phylum of Fungi that appears to be the sister to true fungi.

<span class="mw-page-title-main">Orthokaryotes</span> Proposed clade of eukaryotic organisms

The Orthokaryotes are a proposed Eukaryote clade consisting of the Jakobea and the Neokaryotes. Together with its sister Discicristata it forms a basal Eukaryote clade. They are characterized by stacked Golgi, orthogonal centrioles, and two opposite posterior ciliary roots.

The Scotokaryotes (Cavalier-Smith) is a proposed basal Neokaryote clade as sister of the Diaphoretickes. Basal Scotokaryote groupings are the Metamonads, the Malawimonas and the Podiata. In this phylogeny the Discoba are sometimes seen as paraphyletic and basal Eukaryotes.

Andalucina is a suborder of unicellular organisms in the order of Jakobida. Many species in Andalucina inhabit anaerobic environments.

Eolouka is a paraphyletic phylum of protists localized in the clade Discoba. It contains two lineages: Jakobea and Tsukubea, the last containing only one genus, Tsukubamonas.

<span class="mw-page-title-main">Malawimonad</span> Order of flagellates

Malawimonads are a small group of microorganisms with a basal position in the evolutionary tree of eukaryotes, containing only three recognized species. They're considered part of a paraphyletic group known as "Excavata".

References

  1. Cavalier-Smith, Thomas (1 May 2013). "Early evolution of eukaryote feeding modes, cell structural diversity, and classification of the protozoan phyla Loukozoa, Sulcozoa, and Choanozoa". European Journal of Protistology. 49 (2): 115–178. doi:10.1016/j.ejop.2012.06.001. PMID   23085100.
  2. Al Jewari, Caesar; Baldauf, Sandra L. (28 April 2023). "An excavate root for the eukaryote tree of life". Science Advances. 9 (17): eade4973. Bibcode:2023SciA....9E4973A. doi:10.1126/sciadv.ade4973. ISSN   2375-2548. PMC   10146883 . PMID   37115919.
  3. Derelle, Romain; Torruella, Guifré; Klimeš, Vladimír; Brinkmann, Henner; Kim, Eunsoo; Vlček, Čestmír; Lang, B. Franz; Eliáš, Marek (17 February 2015). "Bacterial proteins pinpoint a single eukaryotic root". Proceedings of the National Academy of Sciences. 112 (7): E693–E699. Bibcode:2015PNAS..112E.693D. doi: 10.1073/pnas.1420657112 . ISSN   0027-8424. PMC   4343179 . PMID   25646484.
  4. Cavalier-Smith, T.; Chao, E. E.; Snell, E. A.; Berney, C.; Fiore-Donno, A. M.; Lewis, R. (2014). "Multigene eukaryote phylogeny reveals the likely protozoan ancestors of opisthokonts (animals, fungi, choanozoans) and Amoebozoa". Molecular Phylogenetics & Evolution. 81: 71–85. doi: 10.1016/j.ympev.2014.08.012 . PMID   25152275.
  5. Cavalier-Smith, Thomas (23 June 2010). "Kingdoms Protozoa and Chromista and the eozoan root of the eukaryotic tree". Biology Letters. 6 (3): 342–345. doi:10.1098/rsbl.2009.0948. ISSN   1744-9561. PMC   2880060 . PMID   20031978.
  6. He, Ding; Fiz-Palacios, Omar; Fu, Cheng-Jie; Fehling, Johanna; Tsai, Chun-Chieh; Baldauf, Sandra L. (2014). "An Alternative Root for the Eukaryote Tree of Life". Current Biology. 24 (4): 465–470. doi: 10.1016/j.cub.2014.01.036 . PMID   24508168.
  7. Cavelier Smith (2013). "Early evolution of eukaryote feeding modes, cell structural diversity, and classification of the protozoan phyla Loukozoa, Sulcozoa, and Choanozoa". European Journal of Protistology. 49 (2): 115–178. doi:10.1016/j.ejop.2012.06.001. PMID   23085100.
  8. Hug, Laura A.; Baker, Brett J.; Anantharaman, Karthik; Brown, Christopher T.; Probst, Alexander J.; Castelle, Cindy J.; Butterfield, Cristina N.; Hernsdorf, Alex W.; Amano, Yuki (11 April 2016). "A new view of the tree of life". Nature Microbiology. 1 (5): 16048. doi: 10.1038/nmicrobiol.2016.48 . ISSN   2058-5276. PMID   27572647.
  9. Cavalier-Smith, Thomas; Chao, Ema E.; Lewis, Rhodri (1 June 2016). "187-gene phylogeny of protozoan phylum Amoebozoa reveals a new class (Cutosea) of deep-branching, ultrastructurally unique, enveloped marine Lobosa and clarifies amoeba evolution". Molecular Phylogenetics and Evolution. 99: 275–296. doi: 10.1016/j.ympev.2016.03.023 . PMID   27001604.
  10. Cavalier-Smith, Thomas (5 September 2017). "Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences". Protoplasma. 255 (1): 297–357. doi:10.1007/s00709-017-1147-3. ISSN   0033-183X. PMC   5756292 . PMID   28875267.