Anaeramoeba

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Anaeramoeba
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
(unranked): Excavata
Phylum: Metamonada
Family: Anaeramoebidae
Táborský, Pánek & Čepička 2017
Genus: Anaeramoeba
Táborský, Pánek & Čepička 2017
Type species
Anaeramoeba flamelloides
Táborský, Pánek & Čepička 2017
Species
  • A. flamelloides
  • A. gargantua
  • A. ignava
  • A. megacephala
  • A. oblonga
  • A. parva
  • A. pumila

Anaeramoeba is a genus of anaerobic protists of uncertain phylogenetic position, first described in 2016.

Contents

Description

As the name implies, Anaeramoeba are anaerobic amoeboid organisms which form a fan-like shape similar to that of Flamella . At least two species can also sometimes assume flagellate forms; with either two or four flagella. They contain double-membrane bound organelles called hydrogenosomes, assumed to be derived from mitochondria, [1] usually associated with colonies of unidentified, rod-shaped bacteria. [2]

Discovery and classification

Anaeramoeba specimens were first isolated in 2016, from samples shallow water anoxic ocean sediments collected from around the world. Despite the similarities to Flamella in both morphology and environment, genetic analyses found that Anaeramoeba do not belong within Amoebozoa. [2] The precise phylogenetic position was not identified with strong support, and the genus may represent a newly identified, deep-branching group of protists. [3] Recent classifications have listed them as sister to Parabasalia in Metamonada. [1]

Related Research Articles

<span class="mw-page-title-main">Percolozoa</span> Phylum of Excavata

The Percolozoa are a group of colourless, non-photosynthetic Excavata, including many that can transform between amoeboid, flagellate, and cyst stages.

<span class="mw-page-title-main">Excavata</span> Supergroup of unicellular organisms belonging to the domain Eukaryota

Excavata is an extensive and diverse but paraphyletic group of unicellular Eukaryota. The group was first suggested by Simpson and Patterson in 1999 and the name latinized and assigned a rank by Thomas Cavalier-Smith in 2002. It contains a variety of free-living and symbiotic protists, and includes some important parasites of humans such as Giardia and Trichomonas. Excavates were formerly considered to be included in the now obsolete Protista kingdom. They were distinguished from other lineages based on electron-microscopic information about how the cells are arranged. They are considered to be a basal flagellate lineage.

In Biology, Archezoa is a term that has been introduced by several authors to refer to a group of organisms. Authors include Josef Anton Maximilian Perty, Ernst Haeckel and in the 20th century by Thomas Cavalier-Smith in his classification system. Each author used the name to refer to different arrays of organisms. This reuse by later authors of the same taxon name for different groups of organisms is widely criticized in taxonomy because the inclusion of the name in a sentence does not make sense unless the particular usage is specified. Nonetheless, all uses of 'Archezoa' are now obsolete.

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

The parabasalids are a group of flagellated protists within the supergroup Excavata. Most of these eukaryotic organisms form a symbiotic relationship in animals. These include a variety of forms found in the intestines of termites and cockroaches, many of which have symbiotic bacteria that help them digest cellulose in woody plants. Other species within this supergroup are known parasites, and include human pathogens.

<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">Lobosa</span> Phylum of protozoans

Lobosa is a taxonomic group of amoebae in the phylum Amoebozoa. Most lobosans possess broad, bluntly rounded pseudopods, although one genus in the group, the recently discovered Sapocribrum, has slender and threadlike (filose) pseudopodia. In current classification schemes, Lobosa is a subphylum, composed mainly of amoebae that have lobose pseudopods but lack cilia or flagella.

A mitosome is a mitochondrion-related organelle (MRO) found in a variety of parasitic unicellular eukaryotes, such as members of the supergroup Excavata. The mitosome was first discovered in 1999 in Entamoeba histolytica, an intestinal parasite of humans, and mitosomes have also been identified in several species of Microsporidia and in Giardia intestinalis.

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

The Archamoebae are a group of protists originally thought to have evolved before the acquisition of mitochondria by eukaryotes. They include genera that are internal parasites or commensals of animals. A few species are human pathogens, causing diseases such as amoebic dysentery. The other genera of archamoebae live in freshwater habitats and are unusual among amoebae in possessing flagella. Most have a single nucleus and flagellum, but the giant amoeba Pelomyxa has many of each.

<i>Breviata</i> Genus of flagellated amoebae

Breviata anathema is a single-celled flagellate amoeboid eukaryote, previously studied under the name Mastigamoeba invertens. The cell lacks mitochondria, much like the pelobionts to which the species was previously assigned, 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.

Anaeromonadea is a class of excavates, comprising the oxymonads and Trimastix.

<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">Conosa</span> Phylum of protozoans

Conosa is a grouping of Amoebozoa. It is subdivided into three groups: Archamoeba, Variosea and Mycetozoa.

<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.

<i>Mastigamoeba</i> Genus of flagellar amoeboids

Mastigamoeba is a genus of pelobionts, and treated by some as members of the Archamoebae group of protists. Mastigamoeba are characterized as anaerobic, amitochondriate organisms that are polymorphic. Their dominant life cycle stage is as an amoeboid flagellate. Species are typically free living, though endobiotic species have been described.

<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.

Muranotrichea is a class of free-living marine anaerobic ciliates, that, together with the classes Parablepharismea and Armophorea, form a major clade of obligate anaerobes within the SAL group.

Parablepharismea is a class of free-living marine and brackish anaerobic ciliates that form a major clade of obligate anaerobes within the SAL group, together with the classes Muranotrichea and Armophorea.

Stygiella /ˌstɪ.d͡ʒiˈɛ.lə/ is a genus of free-living marine flagellates belonging to the family Stygiellidae in the jakobids (excavata).

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

Stygiellidae is a family of free-living marine flagellates belonging to the order Jakobida, a deep-branching lineage within the eukaryotic supergroup Discoba. They are unicellular organisms that commonly inhabit anoxic, sulfide-rich and ammonium-rich marine habitats worldwide.

<span class="mw-page-title-main">Corycidia</span> Group of amoebae

Corycidia is a clade of amoeboid protists within the eukaryotic supergroup Amoebozoa. It contains all amoebae of the families Microcoryciidae, which was previously regarded as Arcellinida, and Trichosphaeriidae, which contains the sole genus Trichosphaerium.

References

  1. 1 2 Stairs, Courtney W.; Táborský, Petr; Salomaki, Eric D.; Kolisko, Martin; Pánek, Tomáš; Eme, Laura; Hradilová, Miluše; Vlček, Čestmír; Jerlström-Hultqvist, Jon; Roger, Andrew J.; Čepička, Ivan (2021-12-20). "Anaeramoebae are a divergent lineage of eukaryotes that shed light on the transition from anaerobic mitochondria to hydrogenosomes". Current Biology. 31 (24): 5605–5612.e5. doi: 10.1016/j.cub.2021.10.010 . ISSN   0960-9822. PMID   34710348. S2CID   240054026.
  2. 1 2 Táborský, Petr; Pánek, Tomáš; Čepička, Ivan (2017). "Anaeramoebidae fam. nov., a Novel Lineage of Anaerobic Amoebae and Amoeboflagellates of Uncertain Phylogenetic Position". Protist. 168 (5): 495–526. doi:10.1016/j.protis.2017.07.005. ISSN   1434-4610. PMID   28985627.
  3. Burki, Fabien; Roger, Andrew J.; Brown, Matthew W.; Simpson, Alastair G.B. (2020). "The New Tree of Eukaryotes". Trends in Ecology & Evolution. 35 (1): 43–55. doi: 10.1016/j.tree.2019.08.008 . ISSN   0169-5347. PMID   31606140.