biflagellate

WordNet

having two flagella; "a biflagellate zoospore"

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/06/09 17:18:27」(JST)

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"Flagellata" from Encyclopædia Britannica

"Flagellata" from Ernst Haeckel's Artforms of Nature, 1904

Parasitic excavate (Giardia lamblia)

Green alga (Chlamydomonas)

A flagellate is a cell or organism with one or more whip-like organelles called flagella. The word flagellate also describes a particular construction (or level of organization) characteristic of many protists (eukaryotic organisms) and their means of motion. The term presently does not imply any specific relationship or classification of the organisms that possess flagellae. However, the term "flagellate" is included in other terms (such as "dinoflagellate" and "choanoflagellata") which are more formally characterized.^[1]

Form and behavior

Eukaryotic flagella 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 whip-like organelles called flagella. Some cells in animals may be flagellate, for instance the spermatozoa of most 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 things, 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, and Choanozoa, which make up a group called the opisthokonts, there is a single posterior flagellum. They are from the phylum Mastigophora. They can cause diseases and they can make their own food. 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

Some cells in animals may be flagellate, for instance the spermatozoa of most phyla, or the choanocytes of sponges. Flowering plants do not produce flagellate cells, but ferns, mosses, green algae, some gymnosperms and other closely related plants do. Likewise, most fungi do not produce cells with flagellae, but the primitive fungal chytrids do. For more examples of flagellated cells as specialized cells of multicellular organisms or as life cycle stages, see flagellum.

Flagellates as organisms: the Flagellata

In older classifications, some protozoa were grouped in Flagellata (= Mastigophora), sometimes divided in Phytoflagellata (= Phytomastigina) and Zooflagellata (= Zoomastigina). They were sometimes grouped with Sarcodina (ameboids) in Sarcomastigophora.

Modern classifications place these example genera into the following groups (see Kudo, 1954 and Cavalier-Smith, 2000):

Genera	Newer classification	Older classification
Multicilia, Mastigamoeba, Phalansterium	Amoebozoa	Zoomastigina
Ancyromonas	Apusozoa	Zoomastigina
Cercomonas	Rhizaria	Zoomastigina
Trypanosoma, Bodo, Oxymonas, Giardia, Trichomonas	Excavata	Zoomastigina
Bicosoeca	Chromalveolata > Heterokontophyta > Bicosoecea	Zoomastigina
Salpingoeca, Codosiga	Opisthokonta > Choanoflagellata	Zoomastigina
Cryptomonas	Chromalveolata > Cryptophyta	Phytomastigina
Pontosphaera	Chromalveolata > Haptophyta	Phytomastigina
Chromulina, Synura	Chromalveolata > Heterokontophyta	Phytomastigina
Prorocentrum, Peridinium	Chromalveolata > Alveolata > Dinophyta	Phytomastigina
Chlamydomonas, Volvox, Nephroselmis	Archaeplastida > Viridiplantae > Chlorophyta	Phytomastigina
Euglena	Excavata > Euglenozoa	Phytomastigina

Although the taxonomic group Flagellata was abandoned, the term "flagellate" remains valid as the description of a level of organization. Amoeboflagellates (e.g., some Heterolobosea, Mastigamoeba, Pelomyxa, Cercomonas) have a peculiar type of flagellate/amoeboid organization, in which cells may present flagella and pseudopods, simultaneously or sequentially.

References

^ Cavalier-Smith T. (1995). "Zooflagellate phylogeny and classification". Tsitologiya 37 (11): 1010–29. PMID 8868448.

External links

Flagellata at the US National Library of Medicine Medical Subject Headings (MeSH)
Jeuck, A., & Arndt, H. (2013). A short guide to common heterotrophic flagellates of freshwater habitats based on the morphology of living organisms. Protist, 164 (6): 842-860, [1].
Leadbeater, B.S.C. & Green, J.C., eds. (2000). The Flagellates. Unity, diversity and evolution. Taylor and Francis, London.

English Journal

Evidence of intraflagellar transport and apical complex formation in a free-living relative of the apicomplexa.

Portman N, Foster C, Walker G, Slapeta J.Author information Faculty of Veterinary Science, University of Sydney, New South Wales, Australia.AbstractSince its first description, Chromera velia has attracted keen interest as the closest free-living relative of parasitic Apicomplexa. The life cycle of this unicellular alga is complex and involves a motile biflagellate form. Flagella are thought to be formed in the cytoplasm, a rare phenomenon shared with Plasmodium in which the canonical mode of flagellar assembly, intraflagellar transport, is dispensed with. Here we demonstrate the expression of intraflagellar transport components in C. velia, answering the question of whether this organism has the potential to assemble flagella via the canonical route. We have developed and characterized a culturing protocol that favors the generation of flagellate forms. From this, we have determined a marked shift in the mode of daughter cell production from two to four daughter cells per division as a function of time after passage. We conduct an ultrastructural examination of the C. velia flagellate form by using serial TEM and show that flagellar biogenesis in C. velia occurs prior to cytokinesis. We demonstrate a close association of the flagellar apparatus with a complex system of apical structures, including a micropore, a conoid, and a complex endomembrane system reminiscent of the apical complex of parasitic apicomplexans. Recent work has begun to elucidate the possible flagellar origins of the apical complex, and we show that in C. velia these structures are contemporaneous within a single cell and share multiple connections. We propose that C. velia therefore represents a vital piece in the puzzle of the origins of the apical complex.
Eukaryotic cell.Eukaryot Cell.2014 Jan;13(1):10-20. doi: 10.1128/EC.00155-13. Epub 2013 Sep 20.
Since its first description, Chromera velia has attracted keen interest as the closest free-living relative of parasitic Apicomplexa. The life cycle of this unicellular alga is complex and involves a motile biflagellate form. Flagella are thought to be formed in the cytoplasm, a rare phenomenon shar
PMID 24058169

Antiphase synchronization in a flagellar-dominance mutant of Chlamydomonas.

Leptos KC, Wan KY, Polin M, Tuval I, Pesci AI, Goldstein RE.Author information Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, United Kingdom.AbstractGroups of beating flagella or cilia often synchronize so that neighboring filaments have identical frequencies and phases. A prime example is provided by the unicellular biflagellate Chlamydomonas reinhardtii, which typically displays synchronous in-phase beating in a low-Reynolds number version of breaststroke swimming. We report the discovery that ptx1, a flagellar-dominance mutant of C. reinhardtii, can exhibit synchronization in precise antiphase, as in the freestyle swimming stroke. High-speed imaging shows that ptx1 flagella switch stochastically between in-phase and antiphase states, and that the latter has a distinct waveform and significantly higher frequency, both of which are strikingly similar to those found during phase slips that stochastically interrupt in-phase beating of the wild-type. Possible mechanisms underlying these observations are discussed.
Physical review letters.Phys Rev Lett.2013 Oct 11;111(15):158101. Epub 2013 Oct 8.
Groups of beating flagella or cilia often synchronize so that neighboring filaments have identical frequencies and phases. A prime example is provided by the unicellular biflagellate Chlamydomonas reinhardtii, which typically displays synchronous in-phase beating in a low-Reynolds number version of
PMID 24160630

The mystery of clade X: Orciraptor gen. nov. and Viridiraptor gen. nov. are highly specialised, algivorous amoeboflagellates (Glissomonadida, Cercozoa).

Hess S, Melkonian M.Author information Department of Botany, Cologne Biocenter, University of Cologne, Zülpicher Str. 47b, 50674 Cologne, Germany. Electronic address: shess@magniflash.de.AbstractIn freshwater ecosystems a vast diversity of elusive protists exists that specifically feed on microalgae. Due to difficulties in isolation and long-term maintenance, most of these are still poorly known. In this study stable, bacteria-free cultures of several limnetic, algivorous amoeboflagellates were investigated by light microscopy and molecular phylogenetic analyses. All strains represent naked, biflagellate cells, either occurring as rigid flagellates or as surface-attached amoebae. They perforate cell walls of certain Zygnematophyceae and Chlorophyceae (Viridiplantae) and phagocytose algal cell contents. Time-lapse microscopy revealed the feeding behaviour, locomotional processes and life histories of the amoeboflagellates. Clear differences in cell morphology and food range specificity led to the description of two new, monotypic genera Orciraptor and Viridiraptor, which occupy similar, but distinct ecological niches in aquatic ecosystems as 'necrophytophagous' and 'parasitoid' protists, respectively. Molecular phylogenetic analyses based on 18S rDNA sequence data demonstrated that Orciraptor and Viridiraptor belonged to 'clade X' within the order Glissomonadida (Cercozoa, Rhizaria). In conclusion, we established the phenotypic identity of a clade, which until now was exclusively known from environmental sequences, and erect the new family Viridiraptoridae for 'clade X'. Its algivorous members are compared with other glissomonads and nomenclatural, methodological and ecological aspects of these novel 'raptorial' amoeboflagellates are discussed.
Protist.Protist.2013 Sep;164(5):706-47. doi: 10.1016/j.protis.2013.07.003. Epub 2013 Aug 27.
In freshwater ecosystems a vast diversity of elusive protists exists that specifically feed on microalgae. Due to difficulties in isolation and long-term maintenance, most of these are still poorly known. In this study stable, bacteria-free cultures of several limnetic, algivorous amoeboflagellates
PMID 23994723

Japanese Journal

Pseudophyllomitus vesiculosus (Larsen and Patterson 1990) Lee, 2002, a Poorly Studied Phagotrophic Biflagellate is the First Characterized Member of Stramenopile Environmental Clade MAST-6

Protist 168(4), 439-451, 2017-08
NAID 120006352560

Surface Ornamentation of <i>Cyanophora paradoxa</i> (Cyanophorales, Glaucophyta) Cells as Revealed by Ultra-High Resolution Field Emission Scanning Electron Microscopy

CYTOLOGIA 79(1), 119-123, 2014
NAID 130004448264

クラミドモナス (光合成研究法) -- (植物・藻類・細菌の材料の入手と栽培・培養)

低温科学 67, 17-21, 2008
NAID 120001492975

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