Division of algae
The
glaucophytes
, also known as
glaucocystophytes
or
glaucocystids
, are a small group of unicellular
algae
found in freshwater and moist terrestrial environments,
[1]
[2]
less common today than they were during the
Proterozoic
.
[3]
The stated number of species in the group varies from about 14 to 26.
[4]
[5]
[6]
Together with the
red algae (Rhodophyta)
and the
green algae
plus land plants (
Viridiplantae
or Chloroplastida), they form the
Archaeplastida
.
The glaucophytes are of interest to biologists studying the evolution of
chloroplasts
as they may be similar to the original algal type that led to the red algae and green plants, i.e. glaucophytes may be
basal
Archaeplastida.
[1]
[7]
[4]
Unlike red and green algae, glaucophytes only have
asexual reproduction
.
[8]
Characteristics
[
edit
]
The
plastids
of glaucophytes are known as '
muroplasts
',
[9]
'cyanoplasts', or '
cyanelles
'. Unlike the plastids in other organisms, they have a
peptidoglycan
layer, believed to be a relic of the
endosymbiotic
origin of plastids from
cyanobacteria
.
[1]
[10]
Glaucophytes contain the photosynthetic pigment
chlorophyll a
.
[1]
Along with
red algae
[1]
and
cyanobacteria
, they harvest light via
phycobilisomes
, structures consisting largely of
phycobiliproteins
. The
green algae
and
land plants
have lost that pigment.
[11]
Like red algae, and in contrast to green algae and plants, glaucophytes store
fixed carbon
in the
cytosol
.
[12]
The most early-diverging genus is
Cyanophora
, which only has one or two plastids. When there are two, they are semi-connected.
[13]
Glaucophytes have
mitochondria
with flat
cristae
, and undergo open
mitosis
without
centrioles
. Motile forms have two unequal
flagella
, which may have fine hairs and are anchored by a multilayered system of
microtubules
, both of which are similar to forms found in some green algae.
[11]
Phylogeny
[
edit
]
External
[
edit
]
Together with
red algae
and
Viridiplantae
(
green algae
and
land plants
), glaucophytes form the
Archaeplastida
? a group of
plastid
-containing organisms that may share a unique common ancestor that established an
endosymbiotic
association with a
cyanobacterium
. The relationship among the three groups remains uncertain, although it is most likely that glaucophytes diverged first:
[4]
The alternative, that glaucophytes and red algae form a clade, has been shown to be less plausible, but cannot be ruled out.
[4]
Internal
[
edit
]
The internal phylogeny of the glaucophytes and the number of genera and species varies considerably among taxonomic sources. A phylogeny of the Glaucophyta published in 2017 divided the group into three families, and includes five genera:
[14]
Glaucophyta
|
Cyanophoraceae
|
Cyanophora
|
|
|
Gloeochaetaceae
|
|
|
Glaucocystidaceae
|
|
Glaucocystopsis
|
|
|
Glaucocystis
|
|
|
|
|
|
|
|
Taxonomy
[
edit
]
A 2019 list of the described glaucophyte species has the same three subdivisions, treated as orders, but includes a further five unplaced possible species, producing a total of between 14 and 19 possible species.
[4]
As of March 2022
[update]
,
AlgaeBase
divided glaucophytes into only two groups, placing
Cyanophora
in Glaucocystales rather than Cyanophorales (however the entry was dated 2011).
[15]
AlgaeBase included a total of 26 species in nine genera:
[16]
- Glaucocystales
- Chalarodora
Pascher
? 1 species
- Corynoplastis
Yokoyama, J.L.Scott, G.C.Zuccarello, M.Kajikawa, Y.Hara & J.A.West
? 1 species
- Cyanophora
Korshikov
? 6 species
- Glaucocystis
Itzigsohn
? 13 species
- Glaucocystopsis
Bourrelly
? 1 species
- Peliaina
Pascher
? 1 species
- Strobilomonas
Schiller
? 1 species
- Gloeochaetales
- Cyanoptyche
Pascher
? 1 species
- Gloeochaete
Lagerheim
? 1 species
None of the species of Glaucophyta is particularly common in nature.
[1]
The glaucophytes were considered before as part of family
Oocystaceae
, in the order
Chlorococcales
.
[17]
References
[
edit
]
- ^
a
b
c
d
e
f
Keeling, Patrick J. (2004).
"Diversity and evolutionary history of plastids and their hosts"
.
American Journal of Botany
.
91
(10): 1481?1493.
doi
:
10.3732/ajb.91.10.1481
.
PMID
21652304
.
- ^
Genomic Insights Into the Biology of Algae
- ^
Cruzan, Mitchell B. (2018).
Evolutionary Biology
. Oxford University Press. p. 20.
ISBN
978-0-19-088268-6
.
- ^
a
b
c
d
e
Figueroa-Martinez, Francisco; Jackson, Christopher; Reyes-Prieto, Adrian (2019). "Plastid Genomes from Diverse Glaucophyte Genera Reveal a Largely Conserved Gene Content and Limited Architectural Diversity".
Genome Biology and Evolution
.
11
(1): 174?188.
doi
:
10.1093/gbe/evy268
.
PMC
6330054
.
PMID
30534986
.
- ^
The monoplastidic bottleneck in algae and plant evolution | Journal of Cell Science
- ^
Guiry, M.D.; Guiry, G.M.
"Glaucophyta"
.
AlgaeBase
. World-wide electronic publication, National University of Ireland, Galway
. Retrieved
2022-02-28
.
- ^
Kim, Eunsoo; Graham, Linda E. (2008).
Redfield, Rosemary Jeanne
(ed.).
"EEF2 Analysis Challenges the Monophyly of Archaeplastida and Chromalveolata"
.
PLoS ONE
.
3
(7): e2621.
Bibcode
:
2008PLoSO...3.2621K
.
doi
:
10.1371/journal.pone.0002621
.
PMC
2440802
.
PMID
18612431
.
- ^
Walker, Timothy (2012).
Plants: A Very Short Introduction
. Oxford University Press. p. 10.
ISBN
978-0-19-958406-2
.
- ^
Wise, Robert R.; Hoober, J. Kenneth, eds. (2006).
The structure and function of plastids
. Dordrecht: Springer. pp. 3?21.
ISBN
978-1-4020-4061-0
.
- ^
Miyagishima, Shin-ya; Kabeya, Yukihiro; Sugita, Chieko; Sugita, Mamoru; Fujiwara, Takayuki (2014).
"DipM is required for peptidoglycan hydrolysis during chloroplast division"
.
BMC Plant Biology
.
14
: 57.
doi
:
10.1186/1471-2229-14-57
.
PMC
4015805
.
PMID
24602296
.
- ^
a
b
Skuja, A. (1948). Taxonomie des Phytoplanktons einiger Seen in Uppland, Schweden. Symbolae Botanicae Upsalienses 9(3): 1-399.
Guiry, M.D.; Guiry, G.M.
"Glaucophyta"
.
AlgaeBase
. World-wide electronic publication, National University of Ireland, Galway.
- ^
Ball, S.; Colleoni, C.; Cenci, U.; Raj, J. N.; Tirtiaux, C. (10 January 2011).
"The evolution of glycogen and starch metabolism in eukaryotes gives molecular clues to understand the establishment of plastid endosymbiosis"
.
Journal of Experimental Botany
.
62
(6): 1775?1801.
doi
:
10.1093/jxb/erq411
.
PMID
21220783
.
- ^
de Vries, Jan; Gould, Sven B. (2017-01-01).
"The monoplastidic bottleneck in algae and plant evolution"
.
Journal of Cell Science
.
131
(2). The Company of Biologists.
doi
:
10.1242/jcs.203414
.
ISSN
1477-9137
.
PMID
28893840
.
- ^
Price, Dana C.; Steiner, Jurgen M.; Yoon, Hwan Su; Bhattacharya, Debashish; Loffelhardt, Wolfgang (2016). "Glaucophyta".
Handbook of the Protists
. pp. 1?65.
doi
:
10.1007/978-3-319-32669-6_42-1
.
ISBN
978-3-319-32669-6
.
- ^
Guiry, M.D.; Guiry, G.M.
"
Cyanophora
"
.
AlgaeBase
. World-wide electronic publication, National University of Ireland, Galway
. Retrieved
2022-03-01
.
- ^
Guiry, M.D.; Guiry, G.M.
"Glaucophyta"
.
AlgaeBase
. World-wide electronic publication, National University of Ireland, Galway
. Retrieved
2022-03-01
.
- ^
"Phycokey - Glaucocystis"
.
Extant
life
phyla/divisions by domain
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