Heterolobosea

Heterolobosea
	The three different stages of N. fowleri
Scientific classification
Domain:	Eukaryota
Clade:	Discoba
Phylum:	Percolozoa
Class:	; Page & Blanton 1985
Orders
	Schizopyrenida; Acrasida ; Schröter 1886; Naegleriida ; Starobogatov 1980; Tetramitida ; Doweld 2001; Creneida ; Cavalier-Smith 2021; Percolomonadida ; Cavalier-Smith 1993;

Heterolobosea are a class of Percolozoa. The only member of this class that is infectious to humans is Naegleria fowleri, the causative agent of the often fatal disease amoebic meningitis. Typically, their life cycle alternates between flagellate and amoeboid stages.

Etymology

Life Cycle

Characteristics

Phylogeny

The first broadly sampled comprehensive phylogenomic (phylotranscriptomic) analysis of the group (from 2025) confirmed the monophyly of Heterolobosea and provided a robustly supported backbone of the phylogeny resulting in the revision of the classification of Heterolobosea to the family level.^[1]

The basal split of the cladogram has been confirmed between the subphyla Pharyngomonada (monotypic, with a sole family Pharyngomonadidae) and Tetramitia. In Tetramitia, two main clades (new classes) were identified: Selenaionea, consisting of two orders Neovahlkampfiida and Selenaionida in previously unsuspected but fully supported sister relationship, and Eutetramitea, consisting of orders Creneida, Lyromonadida, Naegleriida (new, including acrasid slime molds), Percolomonadida and Pseudociliatida (represented by the single genus Stephanopogon; not included in the new analysis but analyses based on 18S rRNA gene sequences have repeatedly shown its close relationship to Percolomonadida with high statistical support):^[1]

Heterolobosea

Pharyngomonada

Pharyngomonadida	Pharyngomonadidae

Tetramitia

Selenaionea

	Neovahlkampfiida

	Selenaionida

Eutetramitea

Naegleriida

	Percolomonadida

?	Pseudociliatida

Creneida

Lyromonadida

Taxonomy

These are collectively referred to as schizopyrenids, amoeboflagellates, or vahlkampfids. They also include the acrasids, a group of social amoebae that aggregate to form sporangia. The entire group is usually called the Heterolobosea, but this may be restricted to members with amoeboid stages.

One Heterolobosea classification system is:^[2]

Order Schizopyrenida
- Family Vahlkampfiidae
- Family Gruberellidae
Order Acrasida
- Family Acrasidae

Pleurostomum flabellatum has recently been added to Heterolobosea.^[3]

Full Taxonomy

Subphylum Tetramitia Cavalier-Smith 1993 em. Cavalier-Smith 2008
- Class Heterolobosea Page & Blanton 1985
  - Order Acrasida Schröter 1886
    - Family Acrasidae van Tieghem 1880 ex Hartog 1906
      - Genus Acrasis van Tieghem 1880
      - Genus Allovahlkampfia Walochnik & Mulec 2009
      - Genus Pocheina Loeblich & Tappan 1961 [Guttulina Cienkowski 1873 non D'Orbigny 1839]
      - Genus Solumitrus Wang et al. 2011
  - Order Naegleriida Starobogatov 1980
    - Genus Marinamoeba De Jonckheere et al. 2009
    - Family Tulamoebidae Kirby et al. 2015
      - Genus Aurem Jhin & Park 2018
      - Genus Pleurostomum Namyslowski 1913
      - Genus Tulamoeba Park et al. 2009
    - Family Naegleriidae Kudo 1954 [Schizopyrenidae Singh 1951 ex Singh 1952; Bistadiidae Doflein 1916]
      - Genus Naegleria Aléxéieff 1912 [Adelphamoeba Napolitano, Wall & Ganz 1970; Didascalus Singh 1952; Schizopyrenus Singh 1951 ex Singh 1952]
      - Genus Willaertia de Jonckheere et al. 1984
  - Order Tetramitida Doweld 2001
    - Family Vahlkampfiidae Jollos 1917 s.s.
      - Genus Tetramitus Perty 1852 [Copromastix Aragao 1916; Learamoeba Sawyer et al. 1998, Paratetramitus Darbyshire, Page & Goodfellow 1976, Singhamoeba Sawyer, Nerad & Munson 1992]
      - Genus Vahlkampfia Chatton & LaLung-Bonnaire 1912 [Guttulidium Frenzel 1892]
  - Order Creneida Cavalier-Smith 2021
    - Family Creneidae Pánek et al. 2014
      - Genus Creneis Pánek et al. 2014
  - Order Percolomonadida Cavalier-Smith 1993
    - Family Barbeliidae Arndt 2023
      - Genus Barbelia Arndt 2021
      - Genus Nonamonas Hohlfeld, Meyer & Arndt 2023
    - Family Lulidae Hohlfeld & Arndt 2023
      - Genus Lula Arndt, Nitsche & Carduck 2021
    - Family Percolomonadidae Cavalier-Smith 1993 [Choanogasteraceae]
      - Genus Percolomonas Fenchel & Patterson 1986 [Choanogaster Pochmann 1959]
    - Family Stephanopogonidae Corliss 1961
      - Genus Nakurumonas Carduck, Nitsche & Arndt 2021
      - Genus Stephanopogon Entz 1884

References

^ ^a ^b Pánek, Tomáš; Tice, Alexander K.; Corre, Pia; Hrubá, Pavla; Žihala, David; Kamikawa, Ryoma; Yazaki, Euki; Shiratori, Takashi; Kume, Keitaro; Hashimoto, Tetsuo; Ishida, Ken-ichiro; Hradilová, Miluše; Silberman, Jeffrey D.; Roger, Andrew; Inagaki, Yuji; Eliáš, Marek; Brown, Matthew W.; Čepička, Ivan (March 2025). "An expanded phylogenomic analysis of Heterolobosea reveals the deep relationships, non-canonical genetic codes, and cryptic flagellate stages in the group". Molecular Phylogenetics and Evolution. 204: 108289. Academic Press in Elsevier. Bibcode:2025MolPE.20408289P. doi:10.1016/j.ympev.2025.108289. ISSN 1095-9513. PMID 39826589.
^ "Heterolobosea". Retrieved 2009-03-25.
^ Park JS, Simpson AG, Lee WJ, Cho BC (July 2007). "Ultrastructure and phylogenetic placement within Heterolobosea of the previously unclassified, extremely halophilic heterotrophic flagellate Pleurostomum flabellatum (Ruinen 1938)". Protist. 158 (3): 397–413. doi:10.1016/j.protis.2007.03.004. PMID 17576098.

External links

Tree of Life Heterolobosea

[Pánek_2025-1] Pánek, Tomáš; Tice, Alexander K.; Corre, Pia; Hrubá, Pavla; Žihala, David; Kamikawa, Ryoma; Yazaki, Euki; Shiratori, Takashi; Kume, Keitaro; Hashimoto, Tetsuo; Ishida, Ken-ichiro; Hradilová, Miluše; Silberman, Jeffrey D.; Roger, Andrew; Inagaki, Yuji; Eliáš, Marek; Brown, Matthew W.; Čepička, Ivan (March 2025). "An expanded phylogenomic analysis of Heterolobosea reveals the deep relationships, non-canonical genetic codes, and cryptic flagellate stages in the group". Molecular Phylogenetics and Evolution. 204: 108289. Academic Press in Elsevier. Bibcode:2025MolPE.20408289P. doi:10.1016/j.ympev.2025.108289. ISSN 1095-9513. PMID 39826589.

[urlHeterolobosea-2] "Heterolobosea". Retrieved 2009-03-25.

[pmid17576098-3] Park JS, Simpson AG, Lee WJ, Cho BC (July 2007). "Ultrastructure and phylogenetic placement within Heterolobosea of the previously unclassified, extremely halophilic heterotrophic flagellate Pleurostomum flabellatum (Ruinen 1938)". Protist. 158 (3): 397–413. doi:10.1016/j.protis.2007.03.004. PMID 17576098.

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