This article is about eukaryotic flagellates. For bacterial flagella and their differences, see Flagellum.
A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word flagellate also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagella. However, the term "flagellate" is included in other terms (such as "dinoflagellate" and "choanoflagellata") which are more formally characterized.[1]
Flagella in eukaryotes are supported by microtubules 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 ingested. Flagella often support hairs, called mastigonemes, or contain rods. Their ultrastructure plays an important role in classifying eukaryotes.
Among protoctists and microscopic animals, a flagellate is an organism with one or more flagella. Some cells in other animals may be flagellate, for instance the spermatozoa of most animal phyla. Flowering plants do not produce flagellate cells, but ferns, mosses, green algae, and some gymnosperms and closely related plants do so. Likewise, most fungi do not produce cells with flagellae, but the primitive fungal chytrids do. 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. Among animals, fungi, which are part of a group called the opisthokonts, there is a single posterior flagellum. They are from the phylum Mastigophora. They can cause diseases and are typically heterotrophic. They reproduce by binary fission. They spend most of their existence moving or feeding. Many parasites that affect human health or economy are flagellates. Flagellates are the major consumers of primary and secondary production in aquatic ecosystems - consuming bacteria and other protists.
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):[2][3][4]
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 colourless flagellates were customary grouped in three groups, highly artificial:[7]
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 (A: autotrophic; F: free-living heterotrophic; P: parasitic; S: symbiotic):[8][9]
Although the taxonomic group Flagellata was abandoned, the term "flagellate" is still used as the description of a level of organization and also as an ecological functional group. Another term used is "monadoid", from monad.[11] as in 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 pseudopods, simultaneously or sequentially, while the helioflagellates (e.g., the cercozoan heliomonads/dimorphids, the stramenopile pedinellids and ciliophryids) have a flagellate/heliozoan organization.[12]
References
^Cavalier-Smith T. (1995). "Zooflagellate phylogeny and classification". Tsitologiya. 37 (11): 1010–29. PMID 8868448.
^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.
^Webster, J & Weber, R (2007). Introduction to Fungi (3rd ed.). Cambridge: Cambridge University Press. pp. 23–24, [1]
^Lahr DJ, Parfrey LW, Mitchell EA, Katz LA, Lara E (July 2011). The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms. Proc. Biol. Sci. 278 (1715): 2083–6.
^Tice, Alexander (2015). Understanding the evolution of aggregative multicellularity : a molecular phylogenetic study of the cellular slime mold genera sorodiplophrys and pocheina. ISBN978-1-321-68823-8. OCLC 985464464.
^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, .
^Jeuck, Alexandra; Arndt, Hartmut (2013). "A Short Guide to Common Heterotrophic Flagellates of Freshwater Habitats Based on the Morphology of Living Organisms". Protist. 164 (6): 842–860. doi:10.1016/j.protis.2013.08.003. PMID 24239731.
^Patterson, D.J. (2000). Flagellates: Heterotrophic Protists With Flagella. Tree of Life, .
^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, [4].
^Hoek, C. van den, Mann, D.G. and Jahns, H.M. (1995). Algae An Introduction to Phycology. Cambridge University Press, Cambridge. ISBN0-521-30419-9.
^Mikryukov, K.A. (2001). Heliozoa as a component of marine microbenthos: a study of Heliozoa of the White Sea. Ophelia 54: 51–73.
External links
Wikispecies has information related to Flagellata.
Wikispecies has information related to Mastigophora.
flagellate, confused, with, flagellation, fellate, ciliate, this, article, about, eukaryotic, flagellates, bacterial, flagella, their, differences, flagellum, flagellate, cell, organism, with, more, whip, like, appendages, called, flagella, word, flagellate, a. Not to be confused with flagellation fellate or ciliate This article is about eukaryotic flagellates For bacterial flagella and their differences see Flagellum A flagellate is a cell or organism with one or more whip like appendages called flagella The word flagellate also describes a particular construction or level of organization characteristic of many prokaryotes and eukaryotes and their means of motion The term presently does not imply any specific relationship or classification of the organisms that possess flagella However the term flagellate is included in other terms such as dinoflagellate and choanoflagellata which are more formally characterized 1 Flagellata from Ernst Haeckel s Artforms of Nature 1904 Parasitic Excavata Giardia lamblia Green algae Chlamydomonas Contents 1 Form and behavior 2 Flagellates as specialized cells or life cycle stages 3 Flagellates as organisms the Flagellata 4 References 5 External linksForm and behavior EditFlagella in eukaryotes are supported by microtubules 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 ingested Flagella often support hairs called mastigonemes or contain rods Their ultrastructure plays an important role in classifying eukaryotes Among protoctists and microscopic animals a flagellate is an organism with one or more flagella Some cells in other animals may be flagellate for instance the spermatozoa of most animal phyla Flowering plants do not produce flagellate cells but ferns mosses green algae and some gymnosperms and closely related plants do so Likewise most fungi do not produce cells with flagellae but the primitive fungal chytrids do 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 Among animals fungi which are part of a group called the opisthokonts there is a single posterior flagellum They are from the phylum Mastigophora They can cause diseases and are typically heterotrophic They reproduce by binary fission They spend most of their existence moving or feeding Many parasites that affect human health or economy are flagellates Flagellates are the major consumers of primary and secondary production in aquatic ecosystems consuming bacteria and other protists Flagellata from Encyclopaedia BritannicaFlagellates as specialized cells or life cycle stages EditAn 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 2 3 4 Archaeplastida most green algae zoospores and male gametes except in Zygnematophyceae bryophytes male gametes pteridophytes male gametes some gymnosperms cycads and Ginkgo as male gametes Stramenopiles centric diatoms male gametes brown algae zoospores and gametes oomycetes assexual zoospores and gametes hyphochytrids zoospores labyrinthulomycetes zoospores some chrysophytes some xanthophytes eustigmatophytes Alveolata some apicomplexans gametes Rhizaria some radiolarians probably gametes 5 foraminiferans as gametes Cercozoa plasmodiophoromycetes zoospores and gametes chlorarachniophytes zoospores Amoebozoa myxogastrids Opisthokonta most metazoans male gametes epithelia and choanocytes chytrid fungi zoospores and gametes Excavata some acrasids Pocheina as zoospores 6 Flagellates as organisms the Flagellata EditIn 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 colourless flagellates were customary grouped in three groups highly artificial 7 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 A autotrophic F free living heterotrophic P parasitic S symbiotic 8 9 Archaeplastida volvocids A F prasinophytes A glaucophytes A Stramenopiles bicosoecids F proteromonads F opalines F most chrysophytes A F part of xanthophytes A raphidophytes chloromonads A silicoflagellates A ciliophryids F pedinellids A F Alveolata dinoflagellates A F Colpodella F Rhizaria Cercozoa cercomonads F spongomonads F thaumatomonads F glissomonads F cryomonads F heliomonads dimorphids F ebriids F Amoebozoa Multicilia F phalansteriids F some archamoebae F S Opisthokonta choanoflagellates F Excavata Discoba jakobids F kinetoplastids bodonids F P trypanosomatids P euglenids F A some heteroloboseans P F S Metamonada diplomonads P F retortamonads S Preaxostyla anaeromonads oxymonads S Trimastix F parabasalids trichomonads P S hypermastigids S Eukaryota incertae sedis haptophytes F A cryptophytes F A kathablepharids F Apusozoa apusomondas F ancyromonads F spironemids hemimastigids F collodictyonids diphylleids F Phyllomonas F and about a hundred genera 10 Although the taxonomic group Flagellata was abandoned the term flagellate is still used as the description of a level of organization and also as an ecological functional group Another term used is monadoid from monad 11 as in 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 pseudopods simultaneously or sequentially while the helioflagellates e g the cercozoan heliomonads dimorphids the stramenopile pedinellids and ciliophryids have a flagellate heliozoan organization 12 References Edit Cavalier Smith T 1995 Zooflagellate phylogeny and classification Tsitologiya 37 11 1010 29 PMID 8868448 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 Webster J amp Weber R 2007 Introduction to Fungi 3rd ed Cambridge Cambridge University Press pp 23 24 1 Adl et al 2012 Lahr DJ Parfrey LW Mitchell EA Katz LA Lara E July 2011 The chastity of amoebae re evaluating evidence for sex in amoeboid organisms Proc Biol Sci 278 1715 2083 6 Tice Alexander 2015 Understanding the evolution of aggregative multicellularity a molecular phylogenetic study of the cellular slime mold genera sorodiplophrys and pocheina ISBN 978 1 321 68823 8 OCLC 985464464 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 2 Jeuck Alexandra Arndt Hartmut 2013 A Short Guide to Common Heterotrophic Flagellates of Freshwater Habitats Based on the Morphology of Living Organisms Protist 164 6 842 860 doi 10 1016 j protis 2013 08 003 PMID 24239731 Patterson D J 2000 Flagellates Heterotrophic Protists With Flagella Tree of Life 3 Patterson D J Vors N Simpson A G B amp O Kelly C 2000 Residual Free living and Predatory Heterotrophic Flagellates In Lee J J Leedale G F amp 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 4 Hoek C van den Mann D G and Jahns H M 1995 Algae An Introduction to Phycology Cambridge University Press Cambridge ISBN 0 521 30419 9 Mikryukov K A 2001 Heliozoa as a component of marine microbenthos a study of Heliozoa of the White Sea Ophelia 54 51 73 External links Edit Wikispecies has information related to Flagellata Wikispecies has information related to Mastigophora Flagellata at the US National Library of Medicine Medical Subject Headings MeSH Leadbeater B S C amp Green J C eds 2000 The Flagellates Unity diversity and evolution Taylor and Francis London Flagellata Encyclopaedia Britannica 11th ed 1911 Retrieved from https en wikipedia org w index php title Flagellate amp oldid 1102402572, wikipedia, wiki, book, books, library,
