Apusomonadidae

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Apusomonadidae
Podomonas kaiyoae C.jpg
Podomonas kaiyoae SEM image. AF: anterior flagellum. PF: posterior flagellum. T: tusk. Brackets: acronemes. Arrows and arrowheads: pseudopodium. Scale bar = 5 μm.
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Clade: Amorphea
Clade: Obazoa
Class: Thecomonadea
Cavalier-Smith, 1993 emend. 2013 [1]
Order: Apusomonadida
Karpov & Mylnikov, 1989 [2]
Family: Apusomonadidae
Karpov & Mylnikov, 1989 [2]
Genera

See text

Diversity
28 species

The apusomonads (family Apusomonadidae) 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. [3] [4] [5]

Contents

Characteristics

Apusomonads are small gliding heterotrophic biflagellates (i.e. with two flagella) that possess a proboscis, formed partly or entirely by the anterior flagellum surrounded by a membranous sleeve. There is a pellicle under the dorsal cell membrane that extends into the proboscis sleeve and into a skirt that covers the sides of the cell. Apusomonads present two different cell plans: [6]

Evolution

External relationships

The apusomonads are the sister group to Opisthokonta, the lineage that includes animals, fungi and an array of related protists. Because of this, apusomonads occupy an important phylogenetic position to understand eukaryotic evolution. They retain ancestral characteristics, such as the biflagellate body plan, which in opisthokonts evolves into a uniflagellate plan. [7]

Apusomonads are vital to understanding multicellularity. Genes involved in multicellularity have been found in the apusomonad Thecamonas , [8] such as adhesion proteins, calcium-signaling genes and types of sodium channels characteristic of animals. [6] The genome of the strain " Amastigomonas sp." presents the integrin-mediated adhesion machinery, the primary cell-matrix adhesion mechanism seen in Metazoa (animals). [9]

Amorphea

Internal relationships

Apusomonads are a poorly and narrowly studied group. [6] Currently, the diversity of described apusomonads consists of the round Apusomonas and a wide array of " Amastigomonas -type" organisms that have been reclassified into the genera Thecamonas , Manchomonas , Podomonas , Multimonas , Chelonemonas and, most recently, Catacumbia , Cavaliersmithia , Karpovia , Mylnikovia and Singekia . The relationships between these genera are depicted by the cladogram below. [7]

Taxonomy

History

Apusomonads were first described in 1989 as one family Apusomonadidae inside the monotypic order Apusomonadida, as a group of flagellates containing the genera Apusomonas and Amastigomonas . [2] Later, British protozoologist Thomas Cavalier-Smith classified them within the monotypic class Thecomonadea as part of the paraphyletic phylum Apusozoa. [1] Modern cladistic approaches to eukaryotic classification refer to apusomonads by their order-level name alone. [7] [10]

Classification

There are 10 recognized genera, as well as the " Amastigomonas -like" archetype that includes primitive forms not yet transferred to new genera. [7]

Related Research Articles

<span class="mw-page-title-main">Nucleariida</span> Order of amoebae

Nucleariida is a group of amoebae with filose pseudopods, known mostly from soils and freshwater. They are distinguished from the superficially similar vampyrellids mainly by having mitochondria with discoid cristae, in the absence of superficial granules, and in the way they consume food.

<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> 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">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">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">Thaumatomonadida</span> Order of single-celled organisms

Thaumatomonadida is an order of flagellates.

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

Filasterea is a proposed basal Filozoan clade of single-celled ameboid eukaryotes 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 78 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.

<i>Amastigomonas</i> Genus of protozoa with two flagella

Amastigomonas is a genus of protists belonging to a lineage of biciliated zooflagellates known as Apusomonadida. It was first described in 1931 by Henri de Saedeleer. 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.

<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.

<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.

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

<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

<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.

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.

Mantamonas sphyraenae is a species of marine heterotrophic flagellates described in 2021. It belongs to the Mantamonadida, a basal eukaryotic lineage within a clade known as CRuMs. Its diploid genome is the first to be assembled within the CRuMs group.

Mantamonas vickermani is a species of marine heterotrophic flagellates described in 2021. It belongs to the Mantamonadida, a basal eukaryotic lineage within a clade known as CRuMs.

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 Cavalier-Smith, Thomas (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 Document online. doi:10.1016/j.ejop.2012.06.001. ISSN   0932-4739. PMID   23085100.
  2. 1 2 3 Karpov SA, Mylnikov AP (1989). "БИОЛОГИЯ И УЛЬТРАСТРУКТУРА БЕСЦВЕТНЫХ ЖГУТИКОНОСЦЕВ APUSOMONADIDA ORD.N" [Biology and ultrastructure of colourless flagellates Apusomonadida ord. n.](PDF). Zoologischkeiĭ Zhurnal (in Russian). LXVIII (8): 5–17.
  3. 1 2 Cavalier-Smith, Thomas; Chao, Ema E. (October 2010). "Phylogeny and evolution of Apusomonadida (Protozoa: Apusozoa): new genera and species". Protist . 161 (4): 549–576. doi:10.1016/j.protis.2010.04.002. PMID   20537943.
  4. Brown, Matthew W.; Sharpe, Susan C.; Silberman, Jeffrey D.; Heiss, Aaron A.; Lang, B. Franz; Simpson, Alastair G. B.; Roger, Andrew J. (2013-10-22). "Phylogenomics demonstrates that breviate flagellates are related to opisthokonts and apusomonads". Proceedings of the Royal Society of London B: Biological Sciences. 280 (1769): 20131755. doi:10.1098/rspb.2013.1755. ISSN   0962-8452. PMC   3768317 . PMID   23986111.
  5. Eme, Laura; Sharpe, Susan C.; Brown, Matthew W.; Roger, Andrew J. (2014-08-01). "On the Age of Eukaryotes: Evaluating Evidence from Fossils and Molecular Clocks". Cold Spring Harbor Perspectives in Biology. 6 (8): a016139. doi:10.1101/cshperspect.a016139. ISSN   1943-0264. PMC   4107988 . PMID   25085908.
  6. 1 2 3 4 5 Heiss AA, Lee WJ, Ishida KI, Simpson AG (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 (5): 637–649. doi:10.1111/jeu.12220. PMID   25912654.
  7. 1 2 3 4 5 6 Torruella G, Galindo LJ, Moreira D, Ciobanu M, Heiss AA, Yubuki N, et al. (November 2022). "Expanding the molecular and morphological diversity of Apusomonadida, a deep-branching group of gliding bacterivorous protists". Journal of Eukaryotic Microbiology. 70 (2): e12956. doi:10.1111/jeu.12956. hdl: 2117/404026 .
  8. Sebe-Pedros A, Roger AJ, Lang FB, King N, Ruiz-Trillo I (2010). "Ancient origin of the integrin-mediated adhesion and signaling machinery". Proceedings of the National Academy of Sciences of the United States of America. 107 (22): 10142–10147. doi:10.1073/pnas.1002257107. PMC   2890464 .
  9. Sebé-Pedrós A, Ruiz-Trillo I (2010). "Integrin-mediated adhesion complex". Communicative & Integrative Biology. 3 (5): 475–477. doi:10.4161/cib.3.5.12603. PMC   2974085 .
  10. Adl SM, Bass D, Lane CE, Lukeš J, Schoch CL, Smirnov A, Agatha S, Berney C, Brown MW, Burki F, Cárdenas P, Čepička I, Chistyakova L, del Campo J, Dunthorn M, Edvardsen B, Eglit Y, Guillou L, Hampl V, Heiss AA, Hoppenrath M, James TY, Karnkowska A, Karpov S, Kim E, Kolisko M, Kudryavtsev A, Lahr DJG, Lara E, Le Gall L, Lynn DH, Mann DG, Massana R, Mitchell EAD, Morrow C, Park JS, Pawlowski JW, Powell MJ, Richter DJ, Rueckert S, Shadwick L, Shimano S, Spiegel FW, Torruella G, Youssef N, Zlatogursky V, Zhang Q (2019). "Revisions to the Classification, Nomenclature, and Diversity of Eukaryotes". Journal of Eukaryotic Microbiology. 66 (1): 4–119. doi:10.1111/jeu.12691. PMC   6492006 . PMID   30257078.
  11. Yabuki A, Tame A, Mizuno K (2022). "Podomonas kaiyoae n. sp., a novel apusomonad growing axenically". Journal of Eukaryotic Microbiology. 00: e12946. doi: 10.1111/jeu.12946 .