Editing Chlamydomonas

{{Short description|Genus of algae}}
{{Automatic taxobox
| image = chlamydomonas_(10000x).jpg
| image_caption = [[scanning electron microscope|SEM]] image of flagellated ''Chlamydomonas - Genus of Algae'' (10,000×)
| taxon = Chlamydomonas
| authority = [[Christian Gottfried Ehrenberg|Ehrenb.]]
| subdivision_ranks = Species
| subdivision = See text
}}
[[File:Chlamydomonas caudata.JPG|thumb|Drawings of ''Chlamydomonas caudata Wille''.<ref>[https://www.biodiversitylibrary.org/item/44537#page/79/mode/1up Hazen, Tracy E. 1922. The phylogeny of the genus ''Brachiomonas''. ''Bulletin of the Torrey Botanical Club''. 49(4):75-92, with two plates.]</ref>]]
[[File:Chlamydomonas reinhardtii vector scheme.svg|alt=|thumb|330px|Cross section of a ''Chlamydomonas reinhardtii'' cell]]
[[File:Chlamydomonas EPA.jpg|thumb|Light micrograph of ''Chlamydomonas'' with two flagella just visible at bottom left]]
[[File:Chlamydomonas globosa - 400x (13263097835).jpg|thumb|''Chlamydomonas globosa'', again with two flagella just visible at bottom left]]

'''''Chlamydomonas''''' ({{IPAc-en|ˌ|k|l|æ|m|ɪ|ˈ|d|ɒ|m|ə|n|ə|s|,_|-|d|ə|ˈ|m|oʊ|-}} {{respell|KLAM|ih|DOM|ə|nəs|,_|-|də|MOH|-}}) is a [[genus]] of [[green algae]] consisting of about 150 [[species]]<ref name="Smith">{{Cite book |last=Smith |first=Gilbert Morgan |url=https://archive.org/details/g.-m.-smith-1955-cryptogamic-botany.-vol-1 |title=Cryptogamic Botany. Vol 1: Algae and Fungi |date=1955}}</ref> of [[unicellular organism|unicellular]] [[flagellate]]s, found in stagnant water and on damp soil, in freshwater, seawater, and even in snow as "[[snow algae]]".<ref>{{Cite journal |last1=Hoham |first1=Ronald W. |last2=Bonome |first2=Tomas A. |last3=Martin |first3=Christopher W. |last4=Leebens-Mack |first4=James H. |date=October 2002 |title=A combined 18S rDNA and rbcL phylogenetic analysis of ''Chloromonas'' and ''Chlamydomonas'' (Chlorophyceae, Volvocales ) emphasizing snow and other cold-temperature habitats. |url=https://onlinelibrary.wiley.com/doi/10.1046/j.1529-8817.2002.t01-1-01227.x |journal=Journal of Phycology |language=en |volume=38 |issue=5 |pages=1051–1064 |doi=10.1046/j.1529-8817.2002.t01-1-01227.x |issn=0022-3646}}</ref> ''Chlamydomonas'' is used as a [[model organism]] for [[molecular biology]], especially studies of [[flagellum|flagellar]] motility and [[chloroplast]] dynamics, biogenesis, and genetics. One of the many striking features of ''Chlamydomonas'' is that it contains [[ion channel]]s ([[channelrhodopsins]]) that are directly activated by light. Some [[FLU (plant gene)|regulatory systems]] of ''Chlamydomonas'' are more complex than their [[Homology (biology)|homolog]]s in [[Gymnosperms]], with evolutionarily related [[Regulation of gene expression|regulatory]] proteins being larger and containing additional [[Protein domain|domains]].<ref>{{Cite journal |last1=Falciatore |first1=Angela |last2=Merendino |first2=Livia |last3=Barneche |first3=Fredy |last4=Ceol |first4=Mauro |last5=Meskauskiene |first5=Rasa |last6=Apel |first6=Klaus |last7=Rochaix |first7=Jean-David |date=2005-01-01 |title=The FLP proteins act as regulators of chlorophyll synthesis in response to light and plastid signals in Chlamydomonas |journal=Genes & Development |volume=19 |issue=1 |pages=176–187 |doi=10.1101/gad.321305 |issn=0890-9369 |pmc=540235 |pmid=15630026}}</ref>

[[Molecular phylogeny]] studies indicated that the traditional genus ''Chlamydomonas'' as defined using morphological data, was [[polyphyletic]] within [[Volvocales]]. Many species were subsequently reclassified (e.g.,  ''[[Oogamochlamys]], [[Lobochlamys]]''), and many other "''Chlamydomonas''" s.l. lineages are still to be reclassified.<ref>{{Cite book |url=https://www.taylorfrancis.com/books/9780849379901 |title=Unravelling the algae: the past, present, and future of algal systematics |date=2007-11-26 |publisher=CRC Press |isbn=978-0-429-12614-7 |editor-last=Brodie |editor-first=Juliet |edition=0 |pages=140 |language=en |doi=10.1201/9780849379901 |editor-last2=Lewis |editor-first2=Jane}}</ref><ref>{{Cite book |url=https://books.google.com/books?id=yjnLAwAAQBAJ |title=Freshwater algae of North America: ecology and classification |date=2015 |publisher=Academic Press |isbn=978-0-12-385877-1 |editor-last=Wehr |editor-first=John D. |edition=2 |series=Aquatic Ecology Ser |location=Amsterdam, Netherlands |pages=275–276 |editor-last2=Sheath |editor-first2=Robert G. |editor-last3=Kociolek |editor-first3=John Patrick}}</ref><ref name=Proschold2001>{{cite journal|doi=10.1078/1434-4610-00068 |title=Molecular phylogeny and taxonomic revision of (Chlorophyta). I. Emendation of ''Chlamydomonas'' Ehrenberg and ''Chloromonas'' Gobi, and Description of ''Oogamochlamys'' gen. nov. and ''Lobochlamys'' gen. nov.|date=2001 |last1=Proschold |first1=T. |last2=Marin |first2=B. |last3=Schlösser |first3=U. G. |last4=Melkonian |first4=M. |journal=Protist |volume=152 |issue=4 |pages=265–300 |pmid=11822658 }}</ref>

==Etymology==
The name ''Chlamydomonas'' comes from the Greek roots ''chlamys'', meaning cloak or mantle, and ''monas'', meaning solitary, now used conventionally for unicellular flagellates.<ref name=Harris/>

==Description==

=== Morphology===
All ''Chlamydomonas'' are motile, unicellular organisms. Cells are generally spherical to cylindrical in shape, but may be elongately spindle-shaped,<ref name=AlgaeBase/> and a papilla may be present or absent. Chloroplasts are green and usually cup-shaped.<ref name="Guiry2007">{{Cite book |title=New survey of Clare Island |date=1999 |publisher=Royal Irish Academy |isbn=978-1-874045-71-7 |editor-last=Mac Cárthaigh |editor-first=Críostóir |location=Dublin |editor-last2=Whelan |editor-first2=Kevin |editor-last3=Graham |editor-first3=John Rollisson |editor-last4=Synnott |editor-first4=Donal M. |editor-last5=Royal Irish Academy}}</ref> A key feature of the genus is its two anterior flagella, each as long as the other.<ref name="Harris">{{Cite book |url=https://linkinghub.elsevier.com/retrieve/pii/B9780123708731000010 |title=The Chlamydomonas Sourcebook |date=2009 |publisher=Elsevier |isbn=978-0-12-370873-1 |pages=1–24 |language=en |doi=10.1016/b978-0-12-370873-1.00001-0}}</ref> The flagellar [[microtubule]]s may each be disassembled by the cell to provide spare material to rebuild the other's microtubules if they are damaged.<ref name="Gelfand-Bershadsky-1991">{{cite journal | last1=Gelfand | first1=Vladimir I. | last2=Bershadsky | first2=Alexander D. | title=Microtubule Dynamics: Mechanism, Regulation, and Function | journal=[[Annual Review of Cell Biology]] | publisher=[[Annual Reviews (publisher)|Annual Reviews]] | volume=7 | issue=1 | year=1991 | issn=0743-4634 | doi=10.1146/annurev.cb.07.110191.000521 | pages=93–116| pmid=1809357 }}</ref>

* Cell wall is made up of a glycoprotein and non-cellulosic polysaccharides instead of cellulose.
* Two anteriorly inserted whiplash flagella. Each flagellum originates from a basal granule in the anterior [[papillate]] or non-papillate region of the cytoplasm. Each flagellum shows a typical 9+2 arrangement of the component fibrils.
* Contractile vacuoles are near the bases of flagella.
* Prominent cup or bowl-shaped chloroplast is present. The chloroplast contains bands composed of a variable number of the photosynthetic thylakoids which are not organised into grana-like structures.
* The nucleus is enclosed in a cup-shaped chloroplast, which has a single large [[pyrenoid]] where starch is formed from photosynthetic products. Pyrenoid with starch sheath is present in the posterior end of the chloroplast.
* Eye spot present in the anterior portion of the chloroplast. It consists of two or three, more or less parallel rows of linearly arranged fat droplets.

== Species ==
About 500 species of ''Chlamydomonas'' have been described.<ref name=AlgaeBase>{{AlgaeBase genus|id=43319|name=Chlamydomonas|access-date=2023-12-26}}</ref>
*''Chlamydomonas acidophila''
* ''Chlamydomonas caudata'' {{Au|Wille}}
* ''Chlamydomonas ehrenbergii'' {{Au|Gorozhankin}}<ref name=Guiry2007/>
* ''[[Chlamydomonas elegans]]'' {{Au|G.S.West 1915}}
* ''[[Chlamydomonas moewusii]]''
* ''Chlamydomonas  muriella'' {{Au|J.W.G.Lund 1947}}
* ''[[Chlamydomonas nivalis]]''
* ''Chlamydomonas ovoidae''
* ''Chlamydomonas priscuii''
* ''Chlamydomonas smithii''<ref>{{cite journal |last1=Hoshaw |first1=Robert W. |last2=Ettl |first2=H. |title=''Chlamydomonas smithii'' sp. nov.?A Chlamydomonad Interfertile with Chlamydomonas Reinhardtip |journal=Journal of Phycology |date=September 1966 |volume=2 |issue=3 |pages=93–96 |doi=10.1111/j.1529-8817.1966.tb04600.x|pmid=27053409 |bibcode=1966JPcgy...2...93H |s2cid=30987145 }}</ref>
* ''[[Chlamydomonas reinhardtii]]''<ref>{{Cite journal |last1=Aoyama |first1=Hiroaki |last2=Kuroiwa |first2=Tsuneyoshi |last3=Nakamura |first3=Soichi |date=November 2009 |title=The dynamic behaviour of mitochondria in living zygotes during maturation and meiosis in Chlamydomonas reinhardtii |url=http://www.tandfonline.com/doi/abs/10.1080/09670260903272599 |journal=European Journal of Phycology |language=en |volume=44 |issue=4 |pages=497–507 |doi=10.1080/09670260903272599 |issn=0967-0262}}</ref>

== Ecology ==
''Chlamydomonas'' is widely distributed in freshwater or damp soil.<ref name= Smith/> It is generally found in a habitat rich in ammonium salt. It possesses red eye spots for photosensitivity and reproduces both asexually and sexually.

''Chlamydomonas'''s asexual reproduction occurs by [[zoospore]]s, [[aplanospore]]s, hypnospores, or a palmella stage,<ref>{{cite web |url=http://www.biologydiscussion.com/algae/life-cycle-of-chlamydomonas-with-diagram/53699 |title=Life Cycle of Chlamydomonas (With Diagram) |publisher=BiologyDiscussion.com |date= 2016-09-16|access-date=12 March 2018}}</ref> while its sexual reproduction is through [[isogamy]], [[anisogamy]] or [[oogamy]].

==Nutrition==
Most species are obligate [[phototroph]]s but ''[[Chlamydomonas reinhardtii|C. reinhardtii]]'' and ''C. dysostosis'' are facultative heterotrophs that can grow in the dark in the presence of acetate as a carbon source.

==Uses==
Some ''Chlamydomonas'' are edible.<ref name="USFDAGRAS">{{cite web | url=http://www.cfsanappsexternal.fda.gov/scripts/fdcc/index.cfm?set=GRASNotices | title=Notice to US Food and Drug Administration of the Conclusion that the Intended Use of ''Chlamydomonas reinhardtii'' (THN 6) Dried Biomass Powder is Generally Recognized as Safe | website=US [[Food and Drug Administration]] | number=GRAS Notice (GRN) No. 773 | date=March 21, 2018}}</ref>

==See also==
*[[Intraflagellar transport]]
*[[Chlamydomonas moewusii]]

==References==
{{Reflist}}

==External links==
* [http://www.chlamy.org/ ''Chlamydomonas'' Center]
* [http://plntfdb.bio.uni-potsdam.de/v2.0/index.php?sp_id=CRE ''Chlamydomonas reinhardtii'' Transcription Factor Database] {{Webarchive|url=https://web.archive.org/web/20090425095429/http://plntfdb.bio.uni-potsdam.de/v2.0/index.php?sp_id=CRE |date=2009-04-25 }}
* [http://www.pdbe.org/emsearch/text:chlamydomonas* 3D electron microscopy structures of Chlamydomonas-related proteins at the EM Data Bank(EMDB)]
* [https://archive.today/20130723074505/http://www.seaweed.ie/algae/chlamydomonas.php The Seaweed Site]
* [https://eurekalert.org/pub_releases/2020-08/f-agf081320.php Ancient gene family protects algae from salt and cold in an Antarctic lake], on: EurekAlert!, 20-Aug-2020, on species UWO241 and {{nowrap|ICE-MDV}} in [[Lake Bonney (Antarctica)]]

{{Taxonbar|from=Q133008}}
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[[Category:Chlamydomonadales genera]]
[[Category:Chlamydomonadaceae]]
[[Category:Taxa named by Christian Gottfried Ehrenberg]]