Bigyra és un agrupament d'Heterokonts.[1]
Inclou Bicosoecida, Blastocystis i Labyrinthulida.[1]
També s'ha descrit com contenent Opalozoa, Bicoecia, i Sagenista.[2]
Bigyra és un agrupament d'Heterokonts.
Inclou Bicosoecida, Blastocystis i Labyrinthulida.
També s'ha descrit com contenent Opalozoa, Bicoecia, i Sagenista.
Tekst üüb Öömrang Bigyra san en stam faan Chromista uun di auerstam faan a Heterokonta. Det san miast algen.
Bigyra es un phylo de Heterokonta.
Bigyra san en stam faan Chromista uun di auerstam faan a Heterokonta. Det san miast algen.
Bigyra (Opalozoa) je bazni kladus heterokontnih organizama. Preci Bigyra i vjerojatno svih heterokonta bili su slobodnoživeći fagotrofni organizmi. Bicosoecea i Placididea su jedine grupe u ovom redu koje imaju pradavni način ishrane, putem fagotrofije. Nakon toga, Opalinata i Blastocystea su izmijenile fagotrofgnost predaka sekundarnom osmotrofijom kada su postali životinje ili paraziti životinja.
S druge strane, Labyrinthulea su vjerovatno neovisno izgubiile sposobnost fagotrofije, kada su se prilagodile fungoidnom saprobnom načinu života.[1][2]
Bigyra je parafiletska bazna grupa Heterokonta i predstavlja evolucijski stepen na kojem je heterotrofni prekursor pseudogljiva i okrofitne grupe algi. Sastoji se od kladusa Sagenista i Opalozoa, uspostavljajući sljedeće odnose:[3]
Heterokonta SagenistaEogyrea / Amphitremidae (?)
Opalozoa PlacidozoaBigyra (Opalozoa) je bazni kladus heterokontnih organizama. Preci Bigyra i vjerojatno svih heterokonta bili su slobodnoživeći fagotrofni organizmi. Bicosoecea i Placididea su jedine grupe u ovom redu koje imaju pradavni način ishrane, putem fagotrofije. Nakon toga, Opalinata i Blastocystea su izmijenile fagotrofgnost predaka sekundarnom osmotrofijom kada su postali životinje ili paraziti životinja.
S druge strane, Labyrinthulea su vjerovatno neovisno izgubiile sposobnost fagotrofije, kada su se prilagodile fungoidnom saprobnom načinu života.
Bigyra (from Latin bi- 'twice', and gyrus 'circle')[1] is a possibly paraphyletic phylum of heterotrophic organisms belonging to the Stramenopile lineage.[5][2] It includes the groups Bicosoecida, Opalinata and Labyrinthulea, as well as several small clades that were initially discovered through environmental DNA samples: Nanomonadea, Placididea, Opalomonadea and Eogyrea.[3][6]
Bigyra is a widely distributed group of stramenopile lineages, characterized by an anterior flagellum with tripartite hairs. It contains well-known ecological groups such as the fungi-like slime nets, the flagellate bicosoecids and the opalines.[7]
The slime nets (known as Labyrinthulea, Labyrinthulomycetes or Labyrinthulomycota) are fungus-like heterotrophic, colorless or yellowish protists that absorb nutrients in an osmotrophic or phagotrophic manner, either as free-living amoebae or as networks of anastomosing cytoplasmic threads that extend from a bothrosome. They are typically saprotrophic decomposers of the detrital food web, making organic matter more accessible to grazing protists. Some are parasitic, and others feed on bacteria. They are cosmopolitan, ubiquitous in marine, freshwater and estuarine environments, associated with algae, marine plants and detritus.[7]
The opalines (known as Opalinata) are a diverse assemblage of modified unicellular protists, consisting of three closely-related groups: proteromonads, opalinids and Blastocystis. They inhabit the intestines of various animals and can be found in all continents.[7]
The bicosoecids (known as Bicosoecida) are a small group of marine or freshwater heterotrophic flagellates that feed on bacteria. Their classification has changed multiple times over the years,[8] and is still an unresolved issue.[9]
Bigyra was first described in 1997 by Thomas Cavalier-Smith, as a phylum within Heterokonta that contained three subphyla: 1) the walled saprotrophic Pseudofungi, 2) the non-phagotrophic gut-symbiotic Opalinata, and 3) the phagotrophic zooflagellate Developayella, which received its own subphylum Bigyromonada. These groups would have originated from a common ancestor that had a double ciliary transition zone helix as its synapomorphy. The common ancestor would have evolved from photosynthetic heterokonts, but would have secondarily lost its plastids, as opposed to the photosynthetic Ochrophyta which retain them. Bigyra was, at the time, postulated as a monophyletic group (or clade), followed by a paraphyletic grade of ochrophyte classes.[1][10]
Heterokonta Bigyra Pseudofungi OpalinataPosterior phylogenetic analyses that used 18S rRNA genes revealed that Pseudofungi and Bigyromonadea were more closely related to Ochrophyta than they were to Opalinata, meaning that the synapomorphy of a double helix could have been present in the common ancestor of all heterokonts. This rendered Bigyra paraphyletic. Consequently, Bigyra was revised and modified in 2006 to comprise a different set of three subphyla: 1) Opalozoa, a previously polyphyletic diverse phylum that was modified to only include Opalinata and Nucleohelea; 2) Bicoecea, containing the bicosoecids; and 3) Sagenista, containing the osmotrophic Labyrinthulea. The phylogeny of Bigyra, however, could not be resolved, and its monophyly was weakly supported. The weak support was thought to be caused by all three bigyran lineages diverging from each other very soon after the separation from other heterokonts; this deep branching makes it difficult to find the exact branching order of bigyran clades.[2]
Heterokonta Ochrophyta Pseudofungi OpalozoaBigyra was modified again in 2013 after the discovery of several heterokont clades called MAST (‘marine stramenopiles’), recovered through environmental rDNA sequencing. The subphylum Opalozoa assimilated the bicosoecids in an infraphylum Bikosia, while another new infraphylum Placidozoa assimilated the Opalinata and an array of new clades: Placididea, Nanomonadea (MAST-3) and Opalomonadea (MAST-12), all three classified under the paraphyletic taxon Wobblata. The subphylum Sagenista, on the other hand, received a new class Eogyrea that was composed of several MAST lineages not yet described.[3] Later, one of the MAST clades within Eogyrea would be described as Pseudophyllomitus (MAST-6).[6]
Stramenopiles Gyrista Opalozoa Placidozoa Opalinata SagenistaDespite modern large-scale phylogenomic analyses that use bigger taxon sampling, the validity of Bigyra remains uncertain. The positions of the deep-branching bigyran clades are not consistent among the published studies, and not all the clades are well-represented by genomic and transcriptomic data.[6] Several studies support the monophyly of Bigyra through multi-gene phylogenetic analysis and a rich taxon sampling.[6][11] There is also support for its paraphyly from more recent phylogenetic studies of the 2020s decade.[12][13]
The present classification of Bigyra is as follows:[4][11]
Bigyra (from Latin bi- 'twice', and gyrus 'circle') is a possibly paraphyletic phylum of heterotrophic organisms belonging to the Stramenopile lineage. It includes the groups Bicosoecida, Opalinata and Labyrinthulea, as well as several small clades that were initially discovered through environmental DNA samples: Nanomonadea, Placididea, Opalomonadea and Eogyrea.
Los bigiros (Bigyra) son un filo parafilético de organismos heterocontos. El antepasado de Bigyra y probablemente de todos los heterocontos era un organismo fagótrofo de vida libre. Bicosoecea y Placididea son los únicos grupos de esta línea que retienen el modo de alimentación ancestral mediante fagotrofia. Posteriormente, Opalinata y Blastocystea reemplazaron la capacidad fagótrofa ancestral por una osmotrofia secundaria cuando se convirtieron en comensales o parásitos de los animales. Por su parte, Labyrinthulea probablemente perdió su capacidad fagotrofa independientemente cuando se adaptó a un modo de vida saprobia de tipo fungoide.[3][4][2]
Bigyra es un grupo parafilético basal de los heterokontos y representa un grado evolutivo heterótrofo precursor del grupo de los pseudohongos y de las algas ocrofitas. Está constituido por los clados Sagenista, Opalozoa y Platysulcea estableciéndose las siguientes relaciones:[2][5][6]
Bigyra Opalozoa PlacidozoaLos bigiros (Bigyra) son un filo parafilético de organismos heterocontos. El antepasado de Bigyra y probablemente de todos los heterocontos era un organismo fagótrofo de vida libre. Bicosoecea y Placididea son los únicos grupos de esta línea que retienen el modo de alimentación ancestral mediante fagotrofia. Posteriormente, Opalinata y Blastocystea reemplazaron la capacidad fagótrofa ancestral por una osmotrofia secundaria cuando se convirtieron en comensales o parásitos de los animales. Por su parte, Labyrinthulea probablemente perdió su capacidad fagotrofa independientemente cuando se adaptó a un modo de vida saprobia de tipo fungoide.
Les Bigyra sont un embranchement d'organismes eucaryotes hétérocontées.
Les Bigyra sont un embranchement d'organismes eucaryotes hétérocontées.
Systematyka Domena Eukaryota Klad Bikonta Klad SAR Klad Halvaria Klad Heterokonta Klad BigyraBigyra – takson heterotroficznych organizmów jądrowych w grupie Heterokonta[2].
Należą tu Bicosoecida, Blastocystis oraz Labyrinthulida[2].
Bywa także opisywany jako takson zawierający Opalozoa, Bicoecia oraz Sagenista, wchodzący w skład królestwa Chromista[3].
Bigyra – takson heterotroficznych organizmów jądrowych w grupie Heterokonta.
Należą tu Bicosoecida, Blastocystis oraz Labyrinthulida.
Bywa także opisywany jako takson zawierający Opalozoa, Bicoecia oraz Sagenista, wchodzący w skład królestwa Chromista.
Bigyra, ou Opalozoa, é um cladode organismos heterocontes considerado o grupo basal dos Heterokontophyta.
O antepassado de Bigyra, e provavelmente de todos os heterocontes, era um organismo fagotrófico de vida livre. Bicosoecida e Placididea são os únicos grupos desta linhagem que retiveram o modo de alimentação ancestral fagotrófica. Posteriormente, Opalinata e Blastocystea substituíram a capacidade fagotrófica ancestral por uma osmotrofia secundária quando se converteram em comensais ou parasitas dos animais. Por seu lado, os Labyrinthulea provavelmente perderam a sua capacidade fagotrófica independentemente quando se adaptaram a um modo de vida sapróbio do tipo fungoide.[3][4][5]
Como inicialmente definido, Bigyra era um grupo parafilético basal dos heterocontes que representa um grado evolutivo heterotrófico precursor do grupo dos Pseudofungi e das algas ocrófitas. O grupo é constituído pelos clados Sagenista e Opalozoa, estabelecendo-se as seguintes relações:[2][6]
Heterokonta SagenistaEogyrea / Amphitremidae (?)
Bigyra, ou Opalozoa, é um cladode organismos heterocontes considerado o grupo basal dos Heterokontophyta.
见正文
双环总门(Bigyra)是一个不等鞭毛类的子类群[1] 。
包括Bicosoecea，Labyrinthulomycetes[1]，Opalinea，Proteromonadea以及芽囊原虫纲（Blastocystis）[2] 。
这是一篇與生物相關的小作品。你可以通过编辑或修订扩充其内容。 双环总门(Bigyra)是一个不等鞭毛类的子类群 。
包括Bicosoecea，Labyrinthulomycetes，Opalinea，Proteromonadea以及芽囊原虫纲（Blastocystis） 。
비기라(Bigyra)는 부등편모조류 분류의 일종이다.[1] 비코소에카류, 블라스토키스티스류, 망형충류를 포함하고 있다.[1] 또한 오팔충류, 사게니스타류를 포함하는 것으로 기술되기도 한다.[2]
