WikiDwarf at 14:53, 10 July 2021

2021-07-10T14:53:02Z

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{{Short description|Division of algae}}
{{Automatic taxobox
| name = Glaucophyta
| image = Glaucocystis sp.jpg
| image_caption = ''Glaucocystis'' sp.
| taxon = Glaucophyta
| authority = Skuja 1948
| subdivision_ranks = Class
| subdivision =
* Glaucocystophyceae Schaffner 1922
| synonyms =
* Glaucocystophyta Kies & Kremer, 1986
}}

The '''glaucophytes''', also known as '''glaucocystophytes''' or '''glaucocystids''', are a small group of freshwater unicellular [[algae]],<ref name="keeling">{{cite journal | journal =[[American Journal of Botany]] | year = 2004 | volume = 91 | pages = 1481–1493 | title = Diversity and evolutionary history of plastids and their hosts | author = Patrick J. Keeling | url = http://www.amjbot.org/cgi/content/full/91/10/1481 | doi = 10.3732/ajb.91.10.1481 | issue=10 | pmid=21652304| doi-access = free }}</ref> less common today than they were during the [[Proterozoic]].<ref>[https://books.google.no/books?id=nzRtDwAAQBAJ&pg=PA20&dq=The+glaucophytes+are+less+common+today,+during+the+Proterozoic&hl=no&sa=X&ved=0ahUKEwjq8ZOFhpriAhUfAhAIHUX4CdgQ6AEIKTAA#v=onepage&q=The%20glaucophytes%20are%20less%20common%20today%2C%20during%20the%20Proterozoic&f=false Evolutionary Biology: A Plant Perspective]</ref> Only 15 species have been described, but more species are likely to exist.<ref>[http://jcs.biologists.org/content/131/2/jcs203414 The monoplastidic bottleneck in algae and plant evolution | Journal of Cell Science]</ref> Together with the [[Red algae|red algae (Rhodophyta)]] and the [[green algae]] plus land plants ([[Viridiplantae]] or Chloroplastida), they form the [[Archaeplastida]]. However, the relationships among the red algae, green algae and glaucophytes are unclear,<ref name="palmer">{{cite journal | url = http://www.amjbot.org/cgi/content/full/91/10/1437 | title = The plant tree of life: an overview and some points of view | author = Jeffrey D. Palmer, Douglas E. Soltis & [[Mark Wayne Chase|Mark W. Chase]] | journal =[[American Journal of Botany]] | year = 2004 | volume = 91 | pages = 1437–1445 | doi = 10.3732/ajb.91.10.1437 | issue=10 | pmid=21652302| doi-access = free }}</ref> in large part due to limited study of the glaucophytes.<ref name="Ancestor">{{cite book |title=[[The Ancestor's Tale]] |isbn=978-0544859937 |last1=Dawkins |author-link=Richard Dawkins |first1=Richard |last2=Wong |first2=Yan |year=2016 }}</ref>

The glaucophytes are of interest to biologists studying the development of [[chloroplast]]s because some studies suggest they may be similar to the original algal type that led to green plants and red algae in that they may be [[basal (phylogenetics)|basal]] Archaeplastida.<ref name="keeling" /><ref>{{cite journal | doi = 10.1371/journal.pone.0002621 | year = 2008 | author=Eunsoo Kim & Linda E. Graham | title = EEF2 Analysis Challenges the Monophyly of Archaeplastida and Chromalveolata | volume = 3 | issue = 7 | pages = e2621 | pmid = 18612431 | pmc = 2440802 | journal = [[PLoS ONE]] | editor1-last = Redfield | editor1-first = Rosemary Jeanne | editor1-link = Rosemary Redfield}}</ref>

Unlike red and green algae, glaucophytes only have asexual reproduction.<ref>[https://books.google.no/books?id=Mo0hghNU39kC&pg=PA10&dq=%22Glaucophytes%22+%22Sexual+reproduction+is+unknown+in+this+group+of+plants%22&hl=no&sa=X&ved=0ahUKEwj0s7mQ0triAhVhi8MKHTIvD20Q6AEIKTAA#v=onepage&q=%22Glaucophytes%22%20%22Sexual%20reproduction%20is%20unknown%20in%20this%20group%20of%20plants%22&f=false Plants: A Very Short Introduction]</ref>

==Characteristics==
The [[chloroplast]]s of glaucophytes are known as 'muroplasts',<ref name="Wise—Plastid diversity">{{cite book |last=Wise |first=edited by Robert R.|title=The structure and function of plastids|year=2006|publisher=Springer|location=Dordrecht|isbn=978-1-4020-4061-0|pages=3–21|url=http://www.uwosh.edu/biology/faculty-and-staff/faculty/wise/publications/wise-the-diversity-of-plastid|author2=Hoober, J. Kenneth}}</ref> 'cyanoplasts', or 'cyanelles'. Unlike the chloroplasts in other organisms, they have a [[peptidoglycan]] layer, believed to be a relic of the [[endosymbiotic theory|endosymbiotic]] origin of plastids from [[cyanobacteria]].<ref name="keeling" /><ref name="Miyagishima">{{cite journal |doi=10.1186/1471-2229-14-57 |pmid=24602296 |pmc=4015805 |title=DipM is required for peptidoglycan hydrolysis during chloroplast division |journal=BMC Plant Biology |volume=14 |pages=57 |year=2014 |last1=Miyagishima |first1=Shin-ya |last2=Kabeya |first2=Yukihiro |last3=Sugita |first3=Chieko |last4=Sugita |first4=Mamoru |last5=Fujiwara |first5=Takayuki }}</ref> Glaucophytes contain the photosynthetic pigment [[chlorophyll a]].<ref name="keeling" /> Along with [[red algae]]<ref name="keeling" /> and [[cyanobacteria]], they harvest light via [[phycobilisome]]s, structures consisting largely of [[phycobiliprotein]]s. The [[green algae]] and [[land plant]]s have lost that pigment.<ref name=Skuja>Skuja, A. (1948). Taxonomie des Phytoplanktons einiger Seen in Uppland, Schweden. Symbolae Botanicae Upsalienses 9(3): 1-399.{{AlgaeBase taxon|id=4301|name=Glaucophyta}}</ref> Like red algae, and in contrast to green algae and plants, glaucophytes store [[carbon fixation|fixed carbon]] in the [[cytosol]].<ref name="ball_2011">{{cite journal|last1=Ball|first1=S.|last2=Colleoni|first2=C.|last3=Cenci|first3=U.|last4=Raj|first4=J. N.|last5=Tirtiaux|first5=C.|title=The evolution of glycogen and starch metabolism in eukaryotes gives molecular clues to understand the establishment of plastid endosymbiosis|journal=Journal of Experimental Botany|date=10 January 2011|volume=62|issue=6|pages=1775–1801|doi=10.1093/jxb/erq411|pmid=21220783|doi-access=free}}</ref>

Glaucophytes have [[mitochondrion|mitochondria]] with flat [[cristae]], and undergo open [[mitosis]] without [[centriole]]s. Motile forms have two unequal [[flagella]], which may have fine hairs and are anchored by a multilayered system of [[microtubule]]s, both of which are similar to forms found in some green algae.<ref name=Skuja/>

==Classification==
Phylogeny of Glaucocystophyceae.<ref>{{citation |mode=cs1|doi=10.1007/978-3-319-32669-6_42-1 |contribution=Glaucophyta |title=Handbook of the Protists |pages=1–65 |year=2017 |last1=Price |first1=Dana C. |last2=Steiner |first2=Jürgen M. |last3=Yoon |first3=Hwan Su |last4=Bhattacharya |first4=Debashish |last5=Löffelhardt |first5=Wolfgang |isbn=978-3-319-32669-6 }}</ref>
{{Clade
|style= font-size:80%; line-height:80%
|label1='''Glaucocystophyceae'''
|1={{Clade
|label1=Cyanophoraceae
|1=''Cyanophora''
|2={{Clade
|label1=Gloeochaetaceae
|1={{Clade
|1=''Cyanoptyche''
|2=''Gloeochaete''
}}
|label2=Glaucocystidaceae
|2={{Clade
|1=''Glaucocystopsis''
|2=''Glaucocystis''
}}
}}
}}
}}

Only 13 species of glaucophytes are known, none of which is particularly common in nature.<ref name="keeling" /> The five included [[genus|genera]] are:
* '''Phylum Glaucophyta''' Skuja 1948
** '''Class Glaucocystophyceae''' Schaffner 1922 [Cyanophorophyceae]
*** '''Order Cyanophorales''' Kies & Kramer 1986
**** '''Family Cyanophoraceae''' Kies & Kramer 1986
***** Genus ?''[[Peliaina]]'' Pascher 1929
****** ''[[Peliaina cyanea]]'' Pascher 1929
***** Genus ?''[[Strobilomonas]]'' Schiller 1954
****** ''[[Strobilomonas cyaneus]]'' Schiller 1954
***** Genus ''Cyanophora'' Korshikov 1924 (is motile and lacks a cell wall)
****** ''C. tetracyanea'' Korshikov 1941
****** ''C. biloba'' Kugrens et al. 1999
****** ''C. sudae'' Takahashi & Nozaki 2014
****** ''C. paradoxa'' Korshikov 1924
****** ''C. kugrensii'' Takahashi & Nozaki 2014 
****** ''C. cuspidata'' Takahashi & Nozaki 2014
*** '''Order Gloeochaetales''' Kies & Kremer 1986
**** '''Family Gloeochaetaceae''' Bohlin 1901 ex Skuja 1954
***** Genus ''Cyanoptyche'' Pascher 1929 (is the least studied of the seven genera)
****** ''[[Cyanoptyche gloeocystis]]'' Pascher 1929
***** Genus ''Gloeochaete'' von Lagerheim 1883 [''[[Schrammia]]'' Dangeard 1889 non Britton & Rose 1930 non Guppy 1895; ''[[Cyanochaete]]'' Gobi 1916] (has both motile and immotile stages, and its cell wall does not appear to be composed of cellulose)
****** ''G. wittrockiana'' von Lagerheim 1883 
*** '''Order Glaucocystales''' Bessey 1907
**** '''Family Glaucocystidaceae''' Bohlin 1901 ex West 1904
***** Genus ''Glaucocystopsis'' Bourrelly 1961
****** ''[[Glaucocystopsis africana]]'' Bourrelly 1961
***** Genus ''Glaucocystis'' Itzigsohn 1868 (is immotile, though it retains very short [[vestigial]] flagella, and has a [[cellulose]] wall)
****** ''G. bullosa'' (Kützing 1836) Wille 1919
****** ''G. caucasica'' Tarnogradskii 1957
****** ''G. cingulata'' Bohlin 1897
****** ''G. duplex'' Prescott 1944
****** ''G. molochinearum'' Geitler
****** ''G. simplex'' Tarnogradskii 1959
****** ''G. nostochinearum'' Itzigsohn 1868 ex Rabenh. 1935
****** ''G. geitleri'' Pringsheim 1958 ex Takahashi & Nozaki 2016
****** ''G. incrassata'' (Lemmermann 1908) Takahashi & Nozaki 2016
****** ''G. miyajii'' Takahashi & Nozaki 2016
****** ''G. bhattacharyae'' Takahashi & Nozaki 2016
****** ''G. oocystiformis'' Prescott 1944

The glaucophytes were considered before as part of family [[Oocystaceae]], in the order [[Chlorococcales]].<ref>http://cfb.unh.edu/phycokey/Choices/Glaucophyceae/GLAUCOCYSTIS/Glaucocystis_key.html</ref>

==References==
{{Reflist}}

[[Category:Algal taxonomy]]
[[Category:Archaeplastida]]

Glaucophyte - Revision history

WikiDwarf at 14:53, 10 July 2021