Editing Flagellate

{{Short description|Group of protists with at least one whip-like appendage}}
{{Distinguish|flagellation|fellate|ciliate}}
{{About|eukaryotic flagellates|bacterial flagella and their differences|Flagellum}}
{{Redirect|Mastigophora|the taxonomic synonym of a genus of mosses|Lepidozia}}
[[Image:Haeckel Flagellata.jpg|thumb|"Flagellata" from [[Ernst Haeckel]]'s ''[[Kunstformen der Natur|Artforms of Nature]]'', 1904]] [[Image:Giardia lamblia.jpg|thumb|Parasitic [[Excavata]] (''Giardia lamblia'')]]
[[Image:Chlamydomonas (10000x).jpg|thumb|[[Green algae]] (''[[Chlamydomonas]]'')]]

A '''flagellate''' is a cell or organism with one or more [[whip]]-like [[appendage]]s called [[flagellum|flagella]]. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many [[prokaryote]]s and [[eukaryote]]s and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, several [[Morphological derivation|derivations]] of the term "flagellate" (such as "[[dinoflagellate]]" and "[[choanoflagellate]]") are more formally characterized.<ref name="pmid8868448">{{cite journal |author=Cavalier-Smith T. |title=Zooflagellate phylogeny and classification |journal=Tsitologiya |volume=37 |issue=11 |pages=1010–29 |year=1995 |pmid=8868448 }}</ref>

== Form and behavior ==
[[Flagella]] in eukaryotes are supported by [[microtubule]]s in a characteristic arrangement, with nine fused pairs surrounding two central singlets. These arise from a [[basal body]]. In some flagellates, flagella direct food into a [[cytostome]] or mouth, where food is [[Ingestion|ingested]]. Flagella role in classifying [[eukaryote]]s.

Among [[protoctist]]s and [[microscopic animals]], a flagellate is an organism with one or more flagella. Some cells in other [[animal]]s may be flagellate, for instance the [[spermatozoa]] of most animal phyla. Flowering plants do not produce flagellate cells, but [[fern]]s, [[Bryophyte|mosses]], [[green algae]], and some [[gymnosperm]]s and closely related plants do so.<ref>Philip E. Pack, Ph.D., Cliff's Notes: AP Biology 4th edition.</ref> Likewise, most fungi do not produce cells with flagellae, but the primitive fungal [[chytrids]] do.<ref name="Hibbett2007">{{cite journal | last1 = Hibbett | display-authors = etal | year = 2007 | title = A higher-level phylogenetic classification of the Fungi | journal = Mycologia | volume = 111 | issue = 5 | pages = 509–547 | pmid = 17572334 | doi = 10.1016/j.mycres.2007.03.004 | s2cid = 4686378 }}</ref> Many protists take the form of single-celled flagellates.

Flagella are generally used for [[propulsion]]. They may also be used to create a current that brings in food.  In most such organisms, one or more flagella are located at or near the anterior of the cell (e.g., ''[[Euglena]]''). Often there is one directed forwards and one trailing behind. Many parasites that affect human health or economy are flagellates in at least one stage of life cycle, such as ''[[Naegleria]]'', ''[[Trichomonas]]'' and ''[[Plasmodium]]''.<ref>{{Cite journal |last1=Dash |first1=Manoswini |last2=Sachdeva |first2=Sherry |last3=Bansal |first3=Abhisheka |last4=Sinha |first4=Abhinav |date=2022-06-15 |title=Gametogenesis in Plasmodium: Delving Deeper to Connect the Dots |journal=Frontiers in Cellular and Infection Microbiology |volume=12 |pages=877907 |doi=10.3389/fcimb.2022.877907 |doi-access=free |issn=2235-2988 |pmc=9241518 |pmid=35782151}}</ref><ref>{{Cite journal |last1=Sparagano |first1=O. |last2=Drouet |first2=E. |last3=Brebant |first3=R. |last4=Manet |first4=E. |last5=Denoyel |first5=G. A. |last6=Pernin |first6=P. |title=Use of monoclonal antibodies to distinguish pathogenic Naegleria fowleri (cysts, trophozoites, or flagellate forms) from other Naegleria species |date=1993 |journal=Journal of Clinical Microbiology |volume=31 |issue=10 |pages=2758–2763 |doi=10.1128/jcm.31.10.2758-2763.1993 |issn=0095-1137 |pmid=8253977|pmc=266008 }}</ref> Flagellates are the major consumers of primary and secondary production in [[aquatic ecosystem]]s - consuming bacteria and other protists.{{citation needed|date=June 2024}}[[Image:Flagellata 1.png|thumb|"Flagellata" from [[Encyclopædia Britannica]]]]

== Flagellates as specialized cells or life cycle stages ==

An overview of the occurrence of flagellated cells in eukaryote groups, as specialized cells of multicellular organisms or as life cycle stages, is given below (see also the article [[flagellum]]):<ref>Raven, J.A. 2000. The flagellate condition. In: (B.S.C. Leadbeater and J.C. Green, eds) ''The flagellates. Unity, diversity and evolution''. The Systematics Association Special Volume 59. Taylor and Francis, London. pp. 269–287.</ref><ref>Webster, J & Weber, R (2007). ''Introduction to Fungi'' (3rd ed.). Cambridge: Cambridge University Press. pp. 23–24, [https://books.google.com/books?id=SApIn7IEnucC&pg=PT64]</ref><ref name="Adl et al. 2012">Adl et al. (2012).</ref>
* [[Archaeplastida]]: most [[green algae]] ([[zoospores]] and male [[gamete]]s, except in [[Zygnematophyceae]]), [[bryophyte]]s (male gametes), [[pteridophyte]]s (male gametes), some [[gymnosperm]]s ([[cycad]]s and ''[[Ginkgo]]'', as male gametes)
* [[Stramenopiles]]: centric [[diatom]]s (male gametes), [[brown algae]] (zoospores and gametes), [[oomycete]]s (assexual zoospores and gametes), [[hyphochytrid]]s (zoospores), [[labyrinthulomycetes]] (zoospores), some [[chrysophyte]]s, some [[xanthophyte]]s, [[eustigmatophyte]]s
* [[Alveolata]]: some [[apicomplexan]]s (gametes)
* [[Rhizaria]]: some [[radiolarian]]s (probably gametes),<ref>Lahr DJ, Parfrey LW, Mitchell EA, Katz LA, Lara E (July 2011). [https://www.ncbi.nlm.nih.gov/pubmed/21429931 The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms]. ''Proc. Biol. Sci.'' 278 (1715): 2083–6.</ref> [[foraminiferan]]s (as gametes)
** [[Cercozoa]]: [[Phytomyxea|plasmodiophoromycete]]s (zoospores and gametes), [[chlorarachniophyte]]s (zoospores)
* [[Amoebozoa]]: [[myxogastrid]]s
* [[Opisthokonta]]: most [[metazoan]]s (male gametes, [[epithelia]] and [[choanocyte]]s), [[chytrid]] fungi (zoospores and gametes)
* [[Excavata]]: some [[acrasid]]s (''Pocheina'', as zoospores)<ref>{{Cite book|last=Tice|first=Alexander|url=http://worldcat.org/oclc/985464464|title=Understanding the evolution of aggregative multicellularity : a molecular phylogenetic study of the cellular slime mold genera sorodiplophrys and pocheina|year=2015|publisher=University of Arkansas, Fayetteville |isbn=978-1-321-68823-8|oclc=985464464}}</ref>

==Flagellates as organisms: the Flagellata==
In older classifications, flagellated [[protozoa]] were grouped in '''Flagellata''' (= '''Mastigophora'''), sometimes divided into Phytoflagellata (= Phytomastigina, mostly autotrophic) and Zooflagellata (= Zoomastigina, heterotrophic). They were sometimes grouped with [[Sarcodina]] (ameboids) in the group [[Sarcomastigophora]].

The autotrophic flagellates were grouped similarly to the botanical schemes used for the corresponding algae groups. The [[Biological pigment|colourless]] flagellates were customarily grouped in three groups, highly artificial:<ref>Fritsch, F.E. ''The Structure and Reproduction of the Algae''. Vol. I. Introduction, Chlorophyceae. Xanthophyceae, Chrysophyceae, Bacillariophyceae, Cryptophyceae, Dinophyceae, Chloromonadineae, Euglenineae, Colourless Flagellata. 1935. Cambridge, England: Cambridge University Press, [https://web.archive.org/web/20150615132446/http://krishikosh.egranth.ac.in/bitstream/1/2023644/1/BPT12884.pdf].</ref>
* Protomastigineae, in which absorption of food-particles in holozoic nutrition occurs at a localised point of the cell surface, often at a cytostome, although many groups were merely saprophytes; it included the majority of colourless flagellates, and even many "apochlorotic" algae;
* Pantostomatineae (or Rhizomastigineae), in which the absorption takes place at any point on the cell surface; roughly corresponds to "amoeboflagellates";
* Distomatineae, a group of binucleate "double individuals" with symmetrically distributed flagella and, in many species, two symmetrical mouths; roughly corresponds to current [[Diplomonadida]].

Presently, these groups are known to be highly [[polyphyletic]]. In modern classifications of the protists, the principal flagellated taxa are placed in the following eukaryote groups, which include also non-flagellated forms (where "A", "F", "P" and "S" stands for autotrophic, free-living heterotrophic, parasitic and symbiotic, respectively):<ref>{{cite journal|doi=10.1016/j.protis.2013.08.003|pmid=24239731|title=A Short Guide to Common Heterotrophic Flagellates of Freshwater Habitats Based on the Morphology of Living Organisms|journal=Protist|volume=164|issue=6|pages=842–860|year=2013|last1=Jeuck|first1=Alexandra|last2=Arndt|first2=Hartmut|doi-access=free}}</ref><ref>Patterson, D.J. (2000). Flagellates: Heterotrophic Protists With Flagella. ''Tree of Life'', [https://web.archive.org/web/20150906081210/http://tolweb.org/notes/?note_id=50].</ref>
* [[Archaeplastida]]: [[Volvocales|volvocids]] (A/F), [[prasinophyte]]s (A), [[Glaucophyta|glaucophytes]] (A)
* [[Stramenopiles]]: [[Bicosoecida|bicosoecids]] (F), [[Proteromonadidae|proteromonads]] (F), [[Opalinidae|opalines]] (F), most [[Chrysophyceae|chrysophyte]]s (A/F), part of [[xanthophyte]]s (A), [[Raphidophyte|raphidophytes/chloromonads]] (A), [[silicoflagellate]]s (A), [[Ciliophryida|ciliophryids]] (F), [[pedinellid]]s (A/F)
* [[Alveolata]]: [[Dinoflagellata|dinoflagellates]] (A/F), ''[[Colpodella]]'' (F)
* [[Rhizaria]]
** [[Cercozoa]]: [[Cercomonadida|cercomonads]] (F), [[Spongomonadea|spongomonads]] (F), [[Thaumatomonadida|thaumatomonads]] (F), [[Glissomonadida|glissomonads]] (F), [[Cryomonadida|cryomonads]] (F), [[Heliomonadida|heliomonads/dimorphids]] (F), [[ebriid]]s (F)
* [[Amoebozoa]]: ''[[Multicilia]]'' (F), [[Phalansterium|phalansteriids]] (F), some [[archamoebae]] (F/S)
* [[Opisthokonta]]: [[choanoflagellates]] (F)
* [[Excavata]]
** [[Discoba]]: [[Jakobida|jakobids]] (F), [[Kinetoplastea|kinetoplastids]] ([[Bodonida|bodonid]]s, F/P, [[trypanosomatid]]s, P), [[Euglenida|euglenids]] (F/A), some [[heterolobosea]]ns (P/F/S)
** [[Metamonada]]: [[Diplomonadida|diplomonads]] (P/F), [[retortamonad]]s (S), [[Preaxostyla|Preaxostyla/anaeromonads]]  ([[oxymonad]]s, S, ''[[Trimastix]]'', F, ''[[Paratrimastix]]'', F),  [[parabasalid]]s ([[trichomonad]]s, P/S, [[hypermastigid]]s, S)
* [[Eukaryota]] incertae sedis : [[haptophyte]]s (F/A), [[Cryptophyceae|cryptophyte]]s (F/A), [[Katablepharid|kathablepharids]] (F), [[Apusozoa]] ([[Apusomonadida|apusomondas]], F, [[Ancyromonadida|ancyromonads]], F, [[Spironemidae|spironemids/hemimastigids]], F), [[Collodictyonidae|collodictyonids/diphylleids]] (F), ''[[Phyllomonas]]'' (F), and about a hundred genera<ref>Patterson, D.J., Vørs, N., Simpson, A.G.B. & O'Kelly, C., 2000. Residual Free-living and Predatory Heterotrophic Flagellates. In: Lee, J.J., Leedale, G.F. & Bradbury, P. ''An Illustrated Guide to the Protozoa''. Society of Protozoologists/Allen Press: Lawrence, Kansas, U.S.A, 2nd ed., vol. 2, p. 1302-1328, [https://species.wikimedia.org/wiki/Incertae_sedis_Eukaryota#Patterson.2C_V.C3.B8rs.2C_Simpson.2C_.26_O.27Kelly.2C_in_Lee_et_al._.282000.29].</ref>

Although the taxonomic group Flagellata was abandoned, the term "flagellate" is still used as the description of a [[:de:Organisationsstufe|level of organization]] and also as an [[functional group (ecology)|ecological functional group]]. Another term used is "monadoid", from [[unicellular organism|monad]].<ref>Hoek, C. van den, Mann, D.G. and Jahns, H.M. (1995). ''[https://books.google.com/books?id=xuUoiFesSHMC Algae An Introduction to Phycology]''. Cambridge University Press, Cambridge. {{ISBN|0-521-30419-9}}.
</ref> as in ''[[Monas (genus)|Monas]]'', and ''[[Cryptomonas]]'' and in the groups as listed above.

The amoeboflagellates (e.g., the rhizarian genus ''[[Cercomonas]]'', some amoebozoan [[Archamoebae]], some excavate [[Heterolobosea]]) have a peculiar type of flagellate/[[amoeboid]] organization, in which cells may present flagella and [[pseudopod]]s, simultaneously or sequentially, while the helioflagellates (e.g., the cercozoan [[Heliomonadida|heliomonads/dimorphids]], the stramenopile [[pedinellid]]s and [[ciliophryid]]s) have a flagellate/[[heliozoa]]n organization.<ref>Mikryukov, K.A. (2001). Heliozoa as a component of marine microbenthos: a study of Heliozoa of the White Sea. ''Ophelia'' 54: 51–73.</ref>

==References==
{{Reflist}}

==External links==
{{Wikispecies|Flagellata}}
{{Wikispecies|Mastigophora}}
* {{MeshName|Flagellata}}
* Leadbeater, B.S.C. & Green, J.C., eds. (2000). ''The Flagellates. Unity, diversity and evolution''. Taylor and Francis, London.
* {{Cite EB1911|wstitle=Flagellata|short=x}}

{{Protozoa protist}}
{{Authority control}}

[[Category:Cell biology]]
[[Category:Flagellates| ]]
[[Category:Microbiology]]