Amastigomonas

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Amastigomonas
Amastigomonas cf. mutabilis.webp
Amastigomonas
Bar is 10 micrometres.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Class: Thecomonadea
Order: Apusomonadida
Family: Apusomonadidae
Genus: Amastigomonas
de Saedeleer 1931 [1]
Type species
Amastigomonas debruynei
de Saedeleer 1931
Species
  • A. caudata
  • A. debruynei
  • A. marisrubri

Amastigomonas is a genus of protists belonging to a lineage of biciliated zooflagellates known as Apusomonadida. [2] It was first described in 1931 by Henri de Saedeleer. [1] The current use of Amastigomonas is as a descriptive archetype, with no phylogenetic or taxonomic implications. The term "Amastigomonas-like" is used to refer to all apusomonads that lack the 'derived' characteristics of Apusomonas . [3]

Contents

Description

Organisms under the name "Amastigomonas" have an oval or oblong cell that can generate pseudopodia from the ventral surface. They lack a mastigophore, a projection of the cell body that contains both basal bodies at its end. Like all Apusomonadida, they have two flagella, and the anterior flagellum is surrounded by a membranous sleeve. [3]

Current use of the name

Historically, the name Amastigomonas was used for any apusomonad species that had 'primitive' characteristics compared to the more 'derived' characteristics of Apusomonas . Molecular phylogenetic analyses have shown that Apusomonas branches inside Amastigomonas, making this genus paraphyletic. As a result, many species of Amastigomonas have been reassigned to new genera— Thecamonas , Podomonas , Manchomonas , Multimonas , [4] Chelonemonas , [5] Catacumbia , Cavaliersmithia , Karpovia , Mylnikovia and Singekia —, and no currently cultured apusomonad matches the original description of Amastigomonas. [3]

Apusomonadida

Apusomonas

Manchomonas

Karpovia

Singekia

Chelonemonas

Thecamonas

Cavaliersmithia

Catacumbia

Mylnikovia

Multimonas

Podomonas

"Amastigomonas-like" organisms

Species and distribution

Related Research Articles

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

Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead united by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major eukaryotic group to be recognized mainly through molecular phylogenies. They are the natural predators of many species of bacteria. They are closely related to the phylum Retaria, comprising amoeboids that usually have complex shells, and together form a supergroup called Rhizaria.

<span class="mw-page-title-main">Rhizaria</span> Infrakingdom of protists

The Rhizaria are a diverse and species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthethic, but many foraminifera and radiolaria have a symbiotic relationship with unicellular algae. A multicellular form, Guttulinopsis vulgaris, a cellular slime mold, has been described. This group was used by Cavalier-Smith in 2002, although the term "Rhizaria" had been long used for clades within the currently recognized taxon. Being described mainly from rDNA sequences, they vary considerably in form, having no clear morphological distinctive characters (synapomorphies), but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. In the absence of an apomorphy, the group is ill-defined, and its composition has been very fluid. Some Rhizaria possess mineral exoskeletons, which are in different clades within Rhizaria made out of opal, celestite, or calcite. Certain species can attain sizes of more than a centimeter with some species being able to form cylindrical colonies approximately 1 cm in diameter and greater than 1 m in length. They feed by capturing and engulfing prey with the extensions of their pseudopodia; forms that are symbiotic with unicellular algae contribute significantly to the total primary production of the ocean.

<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">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.

<i>Ancyromonas</i> Genus of protists

Ancyromonas is a genus of basal Eukaryote consisting of heterotrophic flagellates.

<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.

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

Thaumatomonadida is an order of flagellates.

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

Thecofilosea is a class of unicellular testate amoebae belonging to the phylum Cercozoa. They are amoeboflagellates, organisms with flagella and pseudopodia, distinguished from other cercozoa by their scale-lacking test composed of organic material. They are closely related to the Imbricatea, a group of testate amoebae with tests composed of inorganic silica scales.

Thaumatomonas is a genus within Imbricatea of the phylum Cercozoa.

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

Apusomonas is a genus of Apusozoa erected by A. G. Aléxéieff in 1924.

<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.

<i>Podomonas</i> Genus of protists

Podomonas is a genus of apusomonads, a group of small zooflagellates that glide on their posterior cilium. The genus was identified in 2010 as an independent lineage from Apusomonas and Amastigomonas, and consequently were described as their own separate taxon, containing many species previously assigned to Amastigomonas.

<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

Mantamonads are a group of free-living heterotrophic flagellates that move primarily by gliding on surfaces. They are classified as one genus Mantamonas in the monotypic family Mantamonadidae, order Mantamonadida and class Glissodiscea. Previously, they were classified in Apusozoa as sister of the Apusmonadida on the basis of rRNA analyses. However, mantamonads are currently placed in CRuMs on the basis of phylogenomic analyses that identify their closest relatives as the Diphylleida and Rigifilida.

Massisteriidae is a family of granofilosean protists within the phylum Cercozoa.

<span class="mw-page-title-main">Glissomonadida</span> Order of protists

The glissomonads are a group of bacterivorous gliding flagellated protists that compose the order Glissomonadida, in the amoeboflagellate phylum Cercozoa. They comprise a vast, largely undescribed diversity of soil and freshwater organisms. They are the sister group to cercomonads; the two orders form a solid clade of gliding soil-dwelling flagellates called Pediglissa.

Saccharomycomorpha is a genus of non-flagellated protists with a rare yeast-like appearance, containing the single species Saccharomycomorpha psychra. It is the only genus of the family Saccharomycomorphidae, within the cercozoan order Glissomonadida. Before its description in 2021 it was known as clade T, recovered from environmental DNA in previous phylogenetic analyses.

Sainouroidea is a group of microscopic protists belonging to the supergroup Rhizaria, both discovered through molecular phylogenetic analyses. It contains amoeboid flagellates with two flagella. They are either free-living, mostly on fecal matter, or live inside the gut of animals. Among these amoebae, one lineage has independently evolved aggregative multicellularity similarly to slime moulds.

Chelonemonas is a genus of heterotrophic protists. They are unicellular eukaryotes with two flagella, characterized by the presence of a honeycomb or turtle shell pattern on the dorsal surface of their cells that is visible under electron microscopy. They belong to the Apusomonadida, a clade of flagellates related to the opisthokonts, the group containing animals, fungi and their closest protist relatives.

Thecamonadinae is a subfamily of heterotrophic protists. It is a monophyletic group, or clade, of apusomonads, a group of protozoa with two flagella closely related to the eukaryotic supergroup Opisthokonta. The subfamily contains two genera Chelonemonas and Thecamonas, which are found in marine habitats.

References

  1. 1 2 de Saedeleer H (1931). "Niewe of weinig bekende Flagellaten" [New or little known Flagellates]. Natuurwetenschappelijk Tijdschrift (in Dutch). 13: 89–97.
  2. Cavalier-Smith T, Chao EE (May 2003). "Phylogeny of choanozoa, apusozoa, and other protozoa and early eukaryote megaevolution". J. Mol. Evol. 56 (5): 540–63. Bibcode:2003JMolE..56..540C. doi:10.1007/s00239-002-2424-z. PMID   12698292. S2CID   30773513.
  3. 1 2 3 Torruella G, Galindo LJ, Moreira D, Ciobanu M, Heiss AA, Yubuki N, et al. (2022). "Expanding the molecular and morphological diversity of Apusomonadida, a deep-branching group of gliding bacterivorous protists". Journal of Eukaryotic Microbiology. 00: e12956. doi:10.1111/jeu.12956.
  4. Cavalier-Smith T, Chao EE (May 2010). "Phylogeny and Evolution of Apusomonadida (Protozoa: Apusozoa): New Genera and Species". Protist. 161 (4): 549–76. doi:10.1016/j.protis.2010.04.002. PMID   20537943.
  5. 1 2 Heiss AA, Lee WJ, Ishida KI, Simpson AGB (2015). "Cultivation and Characterisation of New Species of Apusomonads (the Sister Group to Opisthokonts), Including Close Relatives of Thecamonas (Chelonemonas n. gen.)". Journal of Eukaryotic Microbiology. 62: 637–649. doi:10.1111/jeu.12220.
  6. Mylnikov AP, Mylnikova ZM (2012). "НОВЫЙ ПСЕВДОПОДИАЛЬНЫЙ ЖГУТИКОНОСЕЦ AMASTIGOMONAS MARISRUBRI (APUSOMONADIDA) ИЗ КРАСНОГО МОРЯ" [A NEW PSEUDOPODIAL FLAGELLATE AMASTIGOMONAS MARISRUBRI (APUSOMONADIDA) FROM THE RED SEA]. Зоологический журнал (Zoological Journal) (in Russian). 91 (4): 387–387.