Breviata

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Breviata
Mastigamoeba invertens.jpg
B. anathema
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Class: Breviatea
Order: Breviatida
Family: Breviatidae
Genus: Breviata
Walker, Dacks & Embley 2006
Type species
Breviata anathema
Walker, Dacks & Embley 2006
Species
  • B. anathema

Breviata anathema is a single-celled flagellate amoeboid eukaryote, previously studied under the name Mastigamoeba invertens. [1] The cell lacks mitochondria, much like the pelobionts [2] to which the species was previously assigned, [1] but has remnant mitochondrial genes, and possesses an organelle believed to be a modified anaerobic mitochondrion, similar to the mitosomes and hydrogenosomes found in other eukaryotes that live in low-oxygen environments. [3]

Early molecular data placed Breviata in the Amoebozoa, but without obvious affinity to known amoebozoan groups. [3] [4] More recently, phylogenomic analysis has shown that the class Breviatea is a sister group to the Opisthokonta and Apusomonadida. Together, these three groups form the clade Obazoa (the term Obazoa is based on an acronym of Opisthokonta, Breviatea, and Apusomonadida, plus ‘zóa’ (pertaining to ‘life’ in Greek)). [5]

Related Research Articles

<span class="mw-page-title-main">Chromista</span> Eukaryotic biological kingdom

Chromista is a proposed but polyphyletic biological kingdom, refined from the Chromalveolata, consisting of single-celled and multicellular eukaryotic species that share similar features in their photosynthetic organelles (plastids). It includes all eukaryotes whose plastids contain chlorophyll c and are surrounded by four membranes. If the ancestor already possessed chloroplasts derived by endosymbiosis from red algae, all non-photosynthetic Chromista have secondarily lost the ability to photosynthesise. Its members might have arisen independently as separate evolutionary groups from the last eukaryotic common ancestor.

<span class="mw-page-title-main">Opisthokont</span> Group of eukaryotes which includes animals and fungi, among other groups

The opisthokonts are a broad group of eukaryotes, including both the animal and fungus kingdoms. The opisthokonts, previously called the "Fungi/Metazoa group", are generally recognized as a clade. Opisthokonts together with Apusomonadida and Breviata comprise the larger clade Obazoa.

<span class="mw-page-title-main">Amorphea</span> Members of the Unikonta, a taxonomic group proposed by Thomas Cavalier-Smith

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">Retortamonad</span> Group of flagellates

The retortamonads are a small group of flagellates, most commonly found in the intestines of animals as commensals, although a free-living species called the Chilomastix cuspidata exists. They are grouped under the taxon, Archezoa. They are usually around 5-20 μm in length, and all of their small subunit ribosomal RNA gene sequences are very similar to each other. There are two genera: Retortamonas with two flagella, and Chilomastix with four. In both cases there are four basal bodies anterior to a prominent feeding groove, and one flagellum is directed back through the cell, emerging from the groove.

<span class="mw-page-title-main">Apusozoa</span> Phylum of micro-organisms

The Apusozoa are a paraphyletic phylum of flagellate eukaryotes. They are usually around 5–20 μm in size, and occur in soils and aquatic habitats, where they feed on bacteria. They are grouped together based on the presence of an organic shell or theca under the dorsal surface of the cell.

<span class="mw-page-title-main">Telonemia</span> Phylum of single-celled organisms

Telonemia is a phylum of microscopic eukaryotes. They are unicellular free-living flagellates with a unique combination of cell structures, including a highly complex cytoskeleton unseen in other eukaryotes. They present characteristics similar to their sister group, the SAR supergroup, such as cortical alveoli, tripartite mastigonemes and filopodia. Together, the two lineages compose the TSAR clade. They are classified in three genera and seven species, although numerous undescribed lineages are known. They are detected in all marine and freshwater environments, where they prey on bacteria and small phytoplankton through phagotrophy.

<i>Capsaspora</i> Single-celled eukaryote genus

Capsaspora is a monotypic genus containing the single species Capsaspora owczarzaki. C. owczarzaki is a single-celled eukaryote that occupies a key phylogenetic position in our understanding of the origin of animal multicellularity, as one of the closest unicellular relatives to animals. It is, together with Ministeria vibrans, a member of the Filasterea clade. This amoeboid protist has been pivotal to unravel the nature of the unicellular ancestor of animals, which has been proved to be much more complex than previously thought.

<i>Malawimonas</i> Genus of micro-organisms

Malawimonas is genus of unicellular, heterotrophic flagellates with uncertain phylogenetic affinities. They have variably being assigned to Excavata and Loukozoa. Recent studies suggest they may be closely related to the Podiata.

<span class="mw-page-title-main">SAR supergroup</span> Eukaryotes superphylum

SAR or Harosa is a highly diverse clade of eukaryotes, often considered a supergroup, that includes stramenopiles (heterokonts), alveolates, and rhizarians. It is a node-based taxon, including all descendants of the three groups' last common ancestor, and comprises most of the now-rejected Chromalveolata. Their sister group has been found to be telonemids, with which they make up the TSAR clade.

<span class="mw-page-title-main">Jakobid</span>

Jakobids are an order of free-living, heterotrophic, flagellar eukaryotes in the supergroup Excavata. They are small, and can be found in aerobic and anaerobic environments. The order Jakobida, believed to be monophyletic, consists of only twenty species at present, and was classified as a group in 1993. There is ongoing research into the mitochondrial genomes of jakobids, which are unusually large and bacteria-like, evidence that jakobids may be important to the evolutionary history of eukaryotes.

<span class="mw-page-title-main">Filasterea</span> Basal Filozoan clade

Filasterea is a proposed basal Filozoan clade that includes Ministeria and Capsaspora. It is a sister clade to the Choanozoa in which the Choanoflagellatea and Animals appeared. Originally proposed by Shalchian-Tabrizi et al. in 2008, based on a phylogenomic analysis with dozens of genes. Filasterea was found to be the sister-group to the clade composed of Metazoa and Choanoflagellata within the Opisthokonta, a finding that has been further corroborated with additional, more taxon-rich, phylogenetic analyses.

<span class="mw-page-title-main">Holozoa</span> Clade containing animals and some protists

Holozoa is a clade of organisms that includes animals and their closest single-celled relatives, but excludes fungi and all other organisms. Together they amount to more than 1.5 million species of purely heterotrophic organisms, including around 300 unicellular species. It consists of various subgroups, namely Metazoa and the protists Choanoflagellata, Filasterea, Pluriformea and Ichthyosporea. Along with fungi and some other groups, Holozoa is part of the Opisthokonta, a supergroup of eukaryotes. Choanofila was previously used as the name for a group similar in composition to Holozoa, but its usage is discouraged now because it excludes animals and is therefore paraphyletic.

<span class="mw-page-title-main">Apusomonadidae</span> Group of microorganisms with two flagella

The apusomonads are a group of protozoan zooflagellates that glide on surfaces, and mostly consume prokaryotes. They are of particular evolutionary interest because they appear to be the sister group to the Opisthokonts, the clade that includes both animals and fungi. Together with the Breviatea, these form the Obazoa clade.

<span class="mw-page-title-main">Diaphoretickes</span> Taxon of eukaryotes

Diaphoretickes is a major group of eukaryotic organisms, with over 400,000 species. The majority of the earth's biomass that carries out photosynthesis belongs to Diaphoretickes.

<span class="mw-page-title-main">Holomycota</span> Clade containing fungi and some protists

Holomycota or Nucletmycea are a basal Opisthokont clade as sister of the Holozoa. It consists of the Cristidiscoidea and the kingdom Fungi. The position of nucleariids, unicellular free-living phagotrophic amoebae, as the earliest lineage of Holomycota suggests that animals and fungi independently acquired complex multicellularity from a common unicellular ancestor and that the osmotrophic lifestyle was originated later in the divergence of this eukaryotic lineage. Opisthosporidians is a recently proposed taxonomic group that includes aphelids, Microsporidia and Cryptomycota, three groups of endoparasites.

<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.

<span class="mw-page-title-main">Picozoa</span> Phylum of marine unicellular heterotrophic eukaryotes

Picozoa, Picobiliphyta, Picobiliphytes, or Biliphytes are protists of a phylum of marine unicellular heterotrophic eukaryotes with a size of less than about 3 micrometers. They were formerly treated as eukaryotic algae and the smallest member of photosynthetic picoplankton before it was discovered they do not perform photosynthesis. The first species identified therein is Picomonas judraskeda. They probably belong in the Archaeplastida as sister of the Rhodophyta.

<span class="mw-page-title-main">Cryptista</span> Phylum of algae

Cryptista is a clade of alga-like eukaryotes. It is most likely related to Archaeplastida which includes plants and many algae, within the larger group Diaphoretickes.

<span class="mw-page-title-main">Obazoa</span> Proposed group of single-celled organisms

Obazoa is a proposed sister clade of Amoebozoa. The term Obazoa is based on the OBA acronym for Opisthokonta, Breviatea, and Apusomonadida, the group's three constituent clades.

A supergroup, in evolutionary biology, is a large group of organisms that share one common ancestor and have important defining characteristics. It is an informal, mostly arbitrary rank in biological taxonomy that is often greater than phylum or kingdom, although some supergroups are also treated as phyla.

References

  1. 1 2 Walker G, Dacks JB, Embley MT (2006-02-10). "Ultrastructural Description of Breviata anathema, N. Gen., N. Sp., the Organism Previously Studied as "Mastigamoeba invertens"". The Journal of Eukaryotic Microbiology. 53 (2): 65–78. doi:10.1111/j.1550-7408.2005.00087.x. ISSN   1550-7408. PMID   16579808.
  2. Edgcomb VP, Simpson AGB, Zettler LA, Nerad TA, Patterson DJ, Holder ME, Sogin ML (2002). "Pelobionts are degenerate protists: insights from molecules and morphology". Molecular Biology and Evolution. 19 (6): 978–82. doi: 10.1093/oxfordjournals.molbev.a004157 . ISSN   0737-4038. PMID   12032256. Archived from the original (Free full text) on 2012-07-13.
  3. 1 2 Minge MA, Silberman JD, Orr RJ, Cavalier-Smith T, Shalchian-Tabrizi K, Burki F, Skjæveland A, Jakobsen KS (2008-11-11). "Evolutionary position of breviate amoebae and the primary eukaryote divergence". Proceedings of the Royal Society B: Biological Sciences. 276 (1657): 597–604. doi:10.1098/rspb.2008.1358. PMC   2660946 . PMID   19004754.
  4. Roger AJ, Simpson AGB (2009-02-24). "Evolution: revisiting the root of the eukaryote tree". Current Biology. 19 (4): R165–7. doi: 10.1016/j.cub.2008.12.032 . PMID   19243692.
  5. Brown MW, Sharpe SC, Silberman JD, Heiss AA, Lang BF, Simpson AGB, Roger AJ (2013-10-22). "Phylogenomics demonstrates that breviate flagellates are related to opisthokonts and apusomonads". Proceedings of the Royal Society B: Biological Sciences. 280 (1769): 20131755. doi:10.1098/rspb.2013.1755. ISSN   1471-2954. PMC   3768317 . PMID   23986111.