Breviatea

{{Short description|Group of protists}} {{Automatic taxobox | taxon = Breviatida | authority = Cavalier-Smith, 2004<ref name="CavSmith et al 2004"/> | image = Undescribed breviates 2025 Aguilera-Campos-et-al.jpg | image_caption = [[Differential interference contrast microscopy|Differential interference contrast micrographs]] of four strains of undescribed marine breviates. Scale bars: 5 µm | parent_authority = [[Cavalier-Smith]] 2004 in Cavalier-Smith et al., 2004<ref name="CavSmith et al 2004"/> | display_parents = 4 | subdivision_ranks = Genera | subdivision = * '''[[Breviatidae]]''' ** ''[[Breviata]]'' ** ''[[Subulatomonas]]'' * '''[[Pygsuia|Pygsuidae]]''' ** ''[[Pygsuia]]'' * ''[[Lenisia]]'' | diversity = [[#Classification|4 species]] }}

'''Breviatea''', commonly known as '''breviate amoebae''',<ref name="Brown 2013"/> are a group of free-living, [[amitochondriate]] [[Protist|protists]] with uncertain phylogenetic position.<ref name="Hamann_2016"/> They are [[Flagellate|biflagellate]], and can live in anaerobic (oxygen-free) environments.<ref name="Hamann_2016"/><ref name="Brown 2013"/><ref name="Modern Soil Biology 3rd"/> They are currently placed in the [[Obazoa]] clade.<ref name="Kang 2021"/> They likely do not possess [[Vinculin family|vinculin]] proteins.<ref name="Kang 2021"/> Their metabolism relies on [[Fermentation|fermentative]] production of [[Adenosine triphosphate|ATP]] as an adaptation to their low-oxygen environment.<ref name="Hamann_2016"/>

The lineage emerged roughly one billion years ago, at a time when the oxygen content of the Earth's oceans was low, and they thus developed anaerobic lifestyles. Together with [[Apusomonad|apusomonads]], they are the closest relatives of the [[Opisthokont|opisthokonts]], a group that includes animals and fungi.<ref name="Brown 2013"/><ref name="Hydrogenosomes and Mitosomes"/> ==Characteristics== === Mitochondrion-related organelles === Mitochondrion-related organelles (MROs) are organelles that evolved from a degradation of ancestral, fully functional [[mitochondria]]. Among Breviatea, MROs are present in ''[[Pygsuia]]'', ''[[Breviata]]'' and ''[[Subulatomonas]]''. In the cells of ''Pygsuia'', for which the complete [[transcriptome]] is known, there is a single smooth MRO that lacks a [[mitochondrial genome]] and most components of the [[electron transport chain]]. Of the [[citric acid cycle]] enzymes, which are present in the mitochondria in other organisms, only two are present in ''Pygsuia'': [[fumarase]] and [[succinate dehydrogenase]]. In contrast, ''[[Lenisia]]'' cells contain multiple MROs with [[crista]]e.<ref name="Hydrogenosomes and Mitosomes"/>

== Evolution == Breviatea is a [[clade]] of [[basal group|basal]] [[eukaryote]]s. They are closely related to the [[apusomonad]]s and the [[Opisthokonta]] supergroup, and together they compose the larger clade [[Obazoa]], which is the sister group to [[Amoebozoa]].<ref name="Brown 2013"/> Within Breviatea, the four known species are distributed into smaller clades of two species each: one uniting ''[[Breviata]]'' with ''[[Subulatomonas]]'', and one uniting ''[[Lenisia]]'' with ''[[Pygsuia]]''.<ref name="Hamann_2016"/> {{clade|style=font-size:90%;|label1=[[Podiata]]|1={{clade|1=[[CRuMs]]|label2=[[Amorphea]]|2={{clade|1=[[Amoebozoa]]|label2=[[Obazoa]]|2={{clade|1={{clade|label1='''Breviatea'''|1={{clade|1={{Clade|label1=[[Breviatidae]]|1={{Clade |1=''[[Breviata anathema]]'' |2=''[[Subulatomonas tetraspora]]'' }} }} |2={{Clade |label2=[[Pygsuia|Pygsuidae]] |1=''[[Lenisia limosa]]'' |2=''[[Pygsuia biforma]]'' }}}} }}|2={{clade|1=[[Apusomonadida]]|label2=[[Opisthokonta]]|2={{clade|1=[[Holozoa]]|2=[[Holomycota]]}}}}}}}}}}}} == Taxonomy == === History === The class Breviatea was created in 2004 by British protozoologist [[Thomas Cavalier-Smith]] to group a problematic taxon previously known as ''<nowiki/>'Mastigamoeba invertens'<nowiki/>''. This organism, initially classified in the [[Archamoebae]] within phylum [[Amoebozoa]], appeared to strongly diverge in [[phylogenetic]] trees based on [[ribosomal RNA]] and had a structure very different from other archamoebae. Because of these results, ''<nowiki/>'M. invertens''' was separated into the order '''Breviatida''', contained in the monotypic class '''Breviatea'''.<ref name="CavSmith et al 2004" /> The organism was eventually renamed ''[[Breviata anathema]]''.<ref name="Walker_2006"/> A second genus and species, ''[[Subulatomonas tetraspora]]'', was described in 2011.<ref name="Subulatomonas tetraspora"/> Cavalier-Smith established a family-level rank, [[Breviatidae]], for both genera in 2013.<ref name="Cavalier-Smith et al. 2013"/> The same year, a third genus and species of breviates was described, ''[[Pygsuia biforma]]'',<ref name="Brown 2013"/> later classified by Cavalier-Smith in a separate family [[Pygsuia|Pygsuidae]].<ref>{{Cite journal |last=Cavalier-Smith |first=Thomas |date=2022-05-01 |title=Ciliary transition zone evolution and the root of the eukaryote tree: implications for opisthokont origin and classification of kingdoms Protozoa, Plantae, and Fungi |url=https://doi.org/10.1007/s00709-021-01665-7 |journal=Protoplasma |language=en |volume=259 |issue=3 |pages=487–593 |doi=10.1007/s00709-021-01665-7 |issn=1615-6102 |pmc=9010356 |pmid=34940909 |doi-access=free}}</ref> In 2016, a fourth breviate ''[[Lenisia limosa]]'' was described without a family rank.<ref name="Hamann_2016" /><ref>{{Cite journal |last=Lamża |first=Łukasz |title=Deep-branching eukaryotes and early events in protist evolution |url=https://onlinelibrary.wiley.com/doi/abs/10.1111/brv.70101 |journal=Biological Reviews |language=en |volume=n/a |issue=n/a |doi=10.1111/brv.70101 |issn=1469-185X|url-access=subscription }}</ref>

=== Classification === There are currently four accepted genera, each containing only one species. * ''[[Breviata]]'' {{au|Walker, Dacks & Embley, 2006}}<ref name="Walker_2006"/> ** ''[[Breviata anathema]]'' {{au|Walker, Dacks & Embley, 2006}} *''[[Lenisia]]'' {{au|Hamann et al., 2016}}<ref name="Hamann_2016"/> **''[[Lenisia limosa]]'' {{au|Hamann et al., 2016}} *''[[Pygsuia]]'' {{au|Brown et al., 2013}}<ref name="Brown 2013"/> ** ''[[Pygsuia biforma]]'' {{au|Brown et al., 2013}} *''[[Subulatomonas]]'' {{au|Katz et al., 2011}}<ref name="Subulatomonas tetraspora"/> ** ''[[Subulatomonas tetraspora]]'' {{au|Katz et al., 2011}}

== Distribution == Breviate species have been found in aquatic environments in various parts of the world, including off the coast of [[Prince Edward Island]] on the eastern coast of North America, around the [[San Juan Islands]] on the western coast of North America, off the coast of [[Catalonia]] in Spain<ref>{{Cite journal |last=Aguilera-Campos |first=Karla Iveth |last2=Boisard |first2=Julie |last3=Törnblom |first3=Viktor |last4=Jerlström-Hultqvist |first4=Jon |last5=Behncké-Serra |first5=Ada |last6=Cotillas |first6=Elena Aramendia |last7=Stairs |first7=Courtney Weir |date=2025-01-02 |title=Anaerobic breviate protist survival in microcosms depends on microbiome metabolic function |url=https://academic.oup.com/ismej/article/doi/10.1093/ismejo/wraf171/8228259 |journal=The ISME Journal |language=en |volume=19 |issue=1 |doi=10.1093/ismejo/wraf171 |issn=1751-7362 |pmc=12453579 |pmid=40795332}}</ref>, and in the [[Wadden Sea]] along the coast of Germany<ref name="Hamann_2016" />.

== References == <references>

<ref name="Hamann_2016">{{Cite journal |last1=Hamann |first1=Emmo |last2=Gruber-Vodicka |first2=Harald |last3=Kleiner |first3=Manuel |last4=Tegetmeyer |first4=Halina E. |last5=Riedel |first5=Dietmar |last6=Littmann |first6=Sten |last7=Chen |first7=Jianwei |last8=Milucka |first8=Jana |last9=Viehweger |first9=Bernhard |last10=Becker |first10=Kevin W. |last11=Dong |first11=Xiaoli |last12=Stairs |first12=Courtney W. |last13=Hinrichs |first13=Kai-Uwe |last14=Brown |first14=Matthew W. |last15=Roger |first15=Andrew J. |display-authors=3 |date=2016-06-09 |title=Environmental Breviatea harbor mutualistic Arcobacter epibionts |journal=Nature |volume=534 |issue=7606 |pages=254–258 |doi=10.1038/nature18297 |issn=0028-0836 |pmc=4900452 |pmid=27279223|bibcode=2016Natur.534..254H }}</ref>

<ref name="Cavalier-Smith et al. 2013">{{cite journal |last1=Cavalier-Smith|first1=Thomas |title=Early evolution of eukaryote feeding modes, cell structural diversity, and classification of the protozoan phyla Loukozoa, Sulcozoa, and Choanozoa |journal=European Journal of Protistology |date=May 2013 |volume=49 |issue=2 |pages=115–178 Document online |issn=0932-4739 |doi=10.1016/j.ejop.2012.06.001 |pmid=23085100}}</ref>

<ref name="CavSmith et al 2004">{{cite journal | doi=10.1016/j.ejop.2003.10.001 | title=Molecular phylogeny of Amoebozoa and the evolutionary significance of the unikont Phalansterium | year=2004 | last1=Cavalier-Smith | first1=Thomas | last2=Chao | first2=Ema E.-Y. | last3=Oates | first3=Brian | journal=European Journal of Protistology | volume=40 | pages=21–48 }}</ref>

<ref name="Kang 2021">{{Cite journal |last1=Kang |first1=Seungho |last2=Tice |first2=Alexander K. |last3=Stairs |first3=Courtney W. |last4=Jones |first4=Robert E. |last5=Lahr |first5=Daniel J. G. |last6=Brown |first6=Matthew W. |date=2021-07-26 |title=The integrin-mediated adhesive complex in the ancestor of animals, fungi, and amoebae |journal=Current Biology |language=en |volume=31 |issue=14 |pages=3073–3085.e3 |doi=10.1016/j.cub.2021.04.076 |pmid=34077702 |s2cid=235273235 |issn=0960-9822|doi-access=free }}</ref>

<ref name="Brown 2013">{{Cite journal |last1=Brown |first1=Matthew W. |last2=Sharpe |first2=Susan C. |last3=Silberman |first3=Jeffrey D. |last4=Heiss |first4=Aaron A. |last5=Lang |first5=B. Franz |last6=Simpson |first6=Alastair G. B. |last7=Roger |first7=Andrew J. |date=2013-10-22 |title=Phylogenomics demonstrates that breviate flagellates are related to opisthokonts and apusomonads |journal=Proceedings of the Royal Society B: Biological Sciences |language=en |volume=280 |issue=1769 |article-number=20131755 |doi=10.1098/rspb.2013.1755 |issn=0962-8452 |pmc=3768317 |pmid=23986111}}</ref>

<ref name="Hydrogenosomes and Mitosomes">{{Cite book |editor-last1=Tachezy |editor-first1=Jan |chapter-url=https://books.google.com/books?id=93eoDwAAQBAJ&dq=Breviatea&pg=PA299 |title=Hydrogenosomes and Mitosomes: Mitochondria of Anaerobic Eukaryotes |publisher=Springer Cham|isbn=978-3-030-17941-0 |language=en |volume=9 |series=Microbiology Monographs |chapter=Mitochondrion-Related Organelles in Free-Living Protists|first1=Michelle M.|last1=Leger|first2=Martin|last2=Kolísko|first3=Courtney W.|last3=Stairs|first4=Alastair G. B.|last4=Simpson|doi=10.1007/978-3-030-17941-0|edition=2nd|date=2019|s2cid=199511756 }}</ref>

<ref name="Modern Soil Biology 3rd">{{Cite book |last1=Elsas |first1=Jan Dirk van |url=https://books.google.com/books?id=3J6RDwAAQBAJ&dq=Breviatea&pg=PT217 |title=Modern Soil Microbiology, Third Edition |last2=Trevors |first2=Jack T. |last3=Rosado |first3=Alexandre Soares |last4=Nannipieri |first4=Paolo |date=2019-04-05 |publisher=CRC Press |isbn=978-0-429-60240-5 |language=en }}</ref>

<ref name="Walker_2006">{{cite journal|first1=Giselle|last1=Walker|first2=Joel B.|last2=Dacks|first3=T. Martin|last3=Embley|date=2006|title=Ultrastructural Description of ''Breviata anathema'', N. Gen., N. Sp., the Organism Previously Studied as "''Mastigamoeba invertens''"|journal=Journal of Eukaryotic Microbiology|volume=53|issue=2 |pages=65–78|doi=10.1111/j.1550-7408.2005.00087.x|pmid=16579808 |s2cid=31046569 }}</ref>

<ref name="Subulatomonas tetraspora">{{cite journal|first1=Laura A.|last1=Katz|first2=Jessica|last2=Grant|first3=Laura Wegener|last3=Parfrey|first4=Anastasia|last4=Gant|first5=Charles J.|last5=O'Kelly|first6=O. Roger|last6=Anderson|first7=Robert E.|last7=Molestina|first8=Thomas|last8=Nerad|title=''Subulatomonas tetraspora'' nov. gen. nov. sp. is a Member of a Previously Unrecognized Major Clade of Eukaryotes|journal=Protist|volume=162|issue=5|date=November 2011|pages=762–773|doi=10.1016/j.protis.2011.05.002|pmid=21723191 }}</ref>

</references> {{Life on Earth}} {{Eukaryota}} {{Taxonbar|from=Q21446474}} [[Category:Obazoa]]