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Zagumyonnyi DG, Tikhonenkov DV. A new centrohelid heliozoan, Pterocystis polycristalepis sp. nov., and taxonomic and phylogenetic concerns within Pterista (Haptista: Centroplasthelida). Eur J Protistol 2024; 94:126064. [PMID: 38531148 DOI: 10.1016/j.ejop.2024.126064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 02/13/2024] [Accepted: 02/13/2024] [Indexed: 03/28/2024]
Abstract
A new species of centrohelid heliozoans, Pterocystis polycristalepis sp. nov. (Pterocystidae), was examined using light and electron microscopy. The novel centrohelid is characterized by the presence of leaf-like spine-scales with a broad pedicel-like structure on the proximal part and many subparallel ribs on the lateral wing surface. The plate-scales are ovoid with medial tubular thickening and many subparallel ribs on the very extensive marginal rim. The closely related species Pterocystis striata has also been studied in detail using light and electron microscopy. Phylogenetic analysis of 18S rRNA gene sequences placed both species into a separate clade within Pterista. The closest morphologically characterized species to the new clade is Triangulopteris lacunata. The 18S rRNA sequence of Pseudoraphidiophrys veliformis was grouped within Pterista and found to be closely related to Pterocystis polycristalepis, Pterocystis striata, and Triangulopteris lacunata. Cyst-scales of various shapes, cell and cyst aggregations, syncytia, and a cell with a stalk were revealed in a clonal culture of P. veliformis. Analysis of the morphology and phylogenetic position of the studied species and other centrohelids revealed a large number of taxonomic and phylogenetic problems in Pterista.
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Affiliation(s)
- Dmitry G Zagumyonnyi
- Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, 152742 Borok, Russia.
| | - Denis V Tikhonenkov
- Papanin Institute for Biology of Inland Waters, Russian Academy of Sciences, 152742 Borok, Russia
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2
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Lamża Ł. Diversity of 'simple' multicellular eukaryotes: 45 independent cases and six types of multicellularity. Biol Rev Camb Philos Soc 2023; 98:2188-2209. [PMID: 37475165 DOI: 10.1111/brv.13001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 07/10/2023] [Accepted: 07/13/2023] [Indexed: 07/22/2023]
Abstract
Multicellularity evolved multiple times in the history of life, with most reviewers agreeing that it appeared at least 20 times in eukaryotes. However, a specific list of multicellular eukaryotes with clear criteria for inclusion has not yet been published. Herein, an updated critical review of eukaryotic multicellularity is presented, based on current understanding of eukaryotic phylogeny and new discoveries in microbiology, phycology and mycology. As a result, 45 independent multicellular lineages are identified that fall into six distinct types. Functional criteria, as distinct from a purely topological definition of a cell, are introduced to bring uniformity and clarity to the existing definitions of terms such as colony, multicellularity, thallus or plasmodium. The category of clonal multicellularity is expanded to include: (i) septated multinucleated thalli found in Pseudofungi and early-branching Fungi such as Chytridiomycota and Blastocladiomycota; and (ii) multicellular reproductive structures formed by plasmotomy in intracellular parasites such as Phytomyxea. Furthermore, (iii) endogeneous budding, as found in Paramyxida, is described as a form of multicellularity. The best-known case of clonal multicellularity, i.e. (iv) non-separation of cells after cell division, as known from Metazoa and Ochrophyta, is also discussed. The category of aggregative multicellularity is expanded to include not only (v) pseudoplasmodial forms, such a sorocarp-forming Acrasida, but also (vi) meroplasmodial organisms, such as members of Variosea or Filoreta. A common set of topological, geometric, genetic and life-cycle criteria are presented that form a coherent, philosophically sound framework for discussing multicellularity. A possibility of a seventh type of multicellularity is discussed, that of multi-species superorganisms formed by protists with obligatory bacterial symbionts, such as some members of Oxymonada or Parabasalia. Its inclusion is dependent on the philosophical stance taken towards the concepts of individuality and organism in biology. Taxa that merit special attention are identified, such as colonial Centrohelea, and a new speculative form of multicellularity, possibly present in some reticulopodial amoebae, is briefly described. Because of insufficient phylogenetic and morphological data, not all lineages could be unequivocally identified, and the true total number of all multicellular eukaryotic lineages is therefore higher, likely close to a hundred.
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Affiliation(s)
- Łukasz Lamża
- Copernicus Center for Interdisciplinary Studies, Jagiellonian University, Szczepanska 1, Kraków, 31-011, Poland
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3
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Gerasimova EA, Mindolina YV, Tikhonenkov DV, Kataev VY, Balkin AS, Mikhailov KV, Zagumyonnyi DG, Plotnikov AO, Zlatogursky VV. Unexpected ubiquity of heart-shaped scale morphotype in Centroplasthelida (Haptista): Ancestral trait or multiple acquisitions? J Eukaryot Microbiol 2023; 70:e12992. [PMID: 37452443 DOI: 10.1111/jeu.12992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 06/20/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023]
Abstract
Centrohelids (Haptista: Centroplasthelida) are axopodial protists with a remarkable diversity of external siliceous scale morphologies. It is believed that the last common ancestor of centrohelids had a double layer of siliceous scales composed of plate scales closer to a cell surface and spine scales radiating outwards. The characteristic morphotype of spine scales with a heart-shaped base was once believed to be a unique feature of the genus Choanocystis, as it was defined by Siemensma and Roijackers (1988). Further research revealed that this morphology is present in different and sometimes distantly related lineages: Ozanamiidae, Meringosphaeridae, and Marophryidae. Here, we report the fourth clade, Pterocystidae, which is also revealed to contain representatives having this phenotype. Cernunnos gen. nov. is erected here to place Cernunnos uralica sp. nov., Cernunnos arctica sp. nov., Cernunnos america sp. nov., and Cernunnos antarctica Tikhonenkov et Mylnikov, 2010, Gerasimova comb. nov. C. uralica was studied with scanning electron microscopy and SSU rDNA sequencing. Molecular phylogenetic analysis placed it into marine environmental clade P within Pterocystida. The ubiquity of spine scales with heart-shaped bases could be an example of parallel evolution, but taking into account the considerable similarity it is likely an ancestral trait, acquired from the last common ancestor of centrohelids.
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Affiliation(s)
| | - Yulia V Mindolina
- Institute for Cellular and Intracellular Symbiosis of the Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - Denis V Tikhonenkov
- AquaBioSafe Laboratory, University of Tyumen, Tyumen, Russia
- Papanin Institute for Biology of Inland Waters Russian Academy of Sciences, Borok, Russia
| | - Vladimir Y Kataev
- Institute for Cellular and Intracellular Symbiosis of the Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - Alexander S Balkin
- Institute for Cellular and Intracellular Symbiosis of the Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - Kirill V Mikhailov
- Belozersky Institute for Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Kharkevich Institute for Information Transmission Problems, Russian Academy of Sciences, Moscow, Russia
| | - Dmitry G Zagumyonnyi
- AquaBioSafe Laboratory, University of Tyumen, Tyumen, Russia
- Papanin Institute for Biology of Inland Waters Russian Academy of Sciences, Borok, Russia
| | - Andrey O Plotnikov
- Institute for Cellular and Intracellular Symbiosis of the Ural Branch, Russian Academy of Sciences, Orenburg, Russia
| | - Vasily V Zlatogursky
- Department of Botany, Faculty of Science, University of British Columbia, Vancouver, British Columbia, Canada
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4
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Nicholls KH. Marine and freshwater centrohelid heliozoans (Haptista: Centroplasthelida) in Canada, including taxonomic revisions and descriptions of 22 new species and subspecies. CAN J ZOOL 2023. [DOI: 10.1139/cjz-2022-0114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Canadian coastal waters of the Pacific Ocean and the Atlantic Ocean as well as inland freshwater habitats in Ontario were sampled for centrohelid heliozoans (free-living heterotrophic single-celled organisms) over a period of nearly five decades. More than 60 species and subspecies were revealed, including 1 Triangulopteris, 1 Raphidocystis, 2 Pseudoraphidocystis, 3 Raineriophrys, 4 Pseudoraphidiophrys, 12 Choanocystis, 15 Pterocystis, and 25 Acanthocystis taxa. Of these, 22 were officially named and described as new to science based primarily on the morphology of the siliceous scales that cover the cell. New species were compared with images and/or descriptions of close “relatives” to validate their new species assignments. New data on five species of Acanthocystis and one species of Choanocystis required revisions of their descriptive taxonomy that in some cases resulted in the splitting off of separate species or subspecies. Very little can be concluded about global distribution of centrohelid heliozoans, owing to the paucity of records. For many of the taxa reported here, previous records consist of just one or two findings from other parts of the world. One example is Choanocystis antarctica Tikhonenkov and Mylnikov, 2011 that was previously known only from Antarctic seawater, but is reported here from an Ontario softwater lake.
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Shɨshkin-Skarð Y, Drachko D, Zlatogursky VV. Shedding light on the origin of Acanthocystidae: Ricksol blepharistes gen. n., sp. n. (Ricksolidae fam. n., Panacanthocystida, Centroplasthelida), with notes on the evolution of the genera Acanthocystis, Ozanamia gen. n. (Ozanamiidae fam. n.), and “Heterophrys-like organisms”. ORG DIVERS EVOL 2022. [DOI: 10.1007/s13127-022-00595-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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6
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Centrohelid heliozoans of Ukraine with a description of a new genus and species (Haptista: Centroplasthelida). Eur J Protistol 2022; 86:125916. [DOI: 10.1016/j.ejop.2022.125916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/04/2022] [Accepted: 08/22/2022] [Indexed: 11/15/2022]
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Drachko D, Shɨshkin Y, Zlatogursky VV. On the phylogenetic position of Raphidocystis pallida with some notes on its life cycle. J Eukaryot Microbiol 2022; 69:e12916. [PMID: 35416375 DOI: 10.1111/jeu.12916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/31/2022] [Accepted: 04/06/2022] [Indexed: 11/30/2022]
Abstract
Raphidocystis pallida, a centrohelid heliozoan with unusually shaped tubular siliceous scales, was reisolated from Jamor river, Portugal, and studied with the use of light and electron microscopy. In enriched cultures, the cells were naked, devoid of siliceous external skeleton with the exception of several scales present in one cell. Instead, such cells were covered with a layer of rod-shaped bacteria. In clonal cultures, the cells gradually acquired siliceous coverings typical for this species and retained them in next generations. Phylogenetic position of R. pallida was clarified with SSU rDNA-based molecular phylogenetics, and its placement within the genus Raphidocystis despite unusual coverings structure was confirmed. The implications of phylogenetic placement of R. pallida and possible origins of the previously undescribed naked form were discussed.
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Affiliation(s)
- Daria Drachko
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
- Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, St. Petersburg, Russia
| | - Yegor Shɨshkin
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Vasily V Zlatogursky
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
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Drachko D, Mikhailovskii V, Shishkin Y, Zlatogursky VV. Phylogenetic position and morphology of Raphidiophrys elongata sp. nov. (Haptista: Centroplasthelida) with notes on cyst wall structure and evolution. Eur J Protistol 2021; 81:125836. [PMID: 34624791 DOI: 10.1016/j.ejop.2021.125836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 06/30/2021] [Accepted: 08/09/2021] [Indexed: 10/20/2022]
Abstract
The majority of centrohelids bear external coverings consisting of organic spicules or siliceous scales. Cyst coverings are usually reinforced with additional layers of modified scales. The cyst wall of Raphidiophrys heterophryoidea has an unusual and complex structure. It consists of three different types of scales and includes the mosaic scale layer not known in other centrohelids. During excystment, the cyst wall fragments along the sutures of the mosaic layer. For other Raphidiophrys species, cyst coverings are not studied. The present paper describes a new Raphidiophrys species, R. elongata, belonging to the NC7 environmental clade. Trophozoites bore thin plate scales with reduced upper plate. Under starvation, cysts emerged in clonal cultures. Cyst coverings of R. elongata and R. heterophryoidea were studied in comparison with the use of FIB-SEM. Cyst wall of R. elongata was significantly thinner than in R. heterophryoidea and was formed with 3-5 layers of uniform overlapping scales. No mosaic scale layer was present. During excystment, trophozoite exited cyst shell through random fissure. Possible evolutionary events and driving forces behind the complication of cyst wall within Raphidiophrys were discussed.
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Affiliation(s)
- Daria Drachko
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaja nab. 7/9, 199034 St. Petersburg, Russia; Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, Universitetskaja nab. 1, 199034 St. Petersburg, Russia.
| | - Vladimir Mikhailovskii
- Interdisciplinary Resource Center for Nanotechnology, Research Park, St. Petersburg State University, Universitetskaja nab. 7/9, 199034 St. Petersburg, Russia
| | - Yegor Shishkin
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaja nab. 7/9, 199034 St. Petersburg, Russia
| | - Vasily V Zlatogursky
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaja nab. 7/9, 199034 St. Petersburg, Russia
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9
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Bessudova AY, Firsova AD, Likhoshway YV. Silica-scaled heterotrophic protists Rotosphaerida, Thaumatomonadida, and Centroplasthelida in the large continuous ecosystem connecting Lake Baikal to the Kara Sea. J Eukaryot Microbiol 2021; 69:e12871. [PMID: 34570402 DOI: 10.1111/jeu.12871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heterotrophic protists Rotosphaerida, Thaumatomonadida, and centrohelid heliozoans are among the less studied silicified protists in terms of their biogeography and ecology. These organisms inhabit fresh and brackish water, and leave behind siliceous structural elements after death that are species-specific and amenable to electron microscopic analysis. This paper is the first to present data on species richness and taxonomic structure of silica-scaled heterotrophic protists-rotosphaerids, colorless free-living thaumatomonad flagellates and centrohelid heliozoans-in the large continuous water system of Siberia connecting Lake Baikal to the Kara Sea. In the study area, electron microscopy revealed 21 centrohelid heliozoan species from the genera Raphidiophrys (1), Acanthocystis (7), Choanocystis (3), Raineriophrys (2), Raphidocystis (6), and Pterocystis (2), seven rotosphaerid species from the genera Pinaciophora (3), Turriplaca (2), Rabdiophrys (1), and Pompholyxophrys (1), and one thaumatomonad flagellate species Thaumatomastix. Two species of rotosphaerids, Rabdiophrys cf. anulifera and Pinaciophora tridentata, and two species of centrohelid heliozoans, Acanthocystis cf. tubata, and A. cf. cornuta, were found in the waters of Russia for the first time. The most widespread species in fresh water from Lake Baikal to the Lower Yenissei River were Pinaciophora fluviatilis and Raineriophrys cf. fortesca. These species disappeared from the protist assemblages of the Yenissei gulf of the Kara Sea due to higher salinity, with only three species, Acanthocystis cf. mylnikovi (at 3.12‰ salinity) and A. pectinata and Raphidocystis sp. 2 (at 8‰ salinity), found in the area. The sensitivity of silica-scaled heterotrophic protists to changes in habitat parameters suggests that these microeukaryotes could be new indicator organisms.
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Affiliation(s)
- Anna Yu Bessudova
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, Irkutsk, 664003, Russia
| | - Alena D Firsova
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, Irkutsk, 664003, Russia
| | - Yelena V Likhoshway
- Limnological Institute of the Siberian Branch of the Russian Academy of Sciences, Irkutsk, 664003, Russia
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10
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Shishkin Y, Drachko D, Zlatogursky VV. Clypifer cribrifer gen. nov., sp. nov. (Clypiferidae fam. nov., Pterocystida, Centroplasthelida), with notes on evolution of centrohelid siliceous coverings. Int J Syst Evol Microbiol 2021; 71. [PMID: 34196605 DOI: 10.1099/ijsem.0.004856] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A new family, genus and species of centrohelid heliozoans, Clypifer cribrifer gen. nov., sp. nov. (Clypiferidae fam. nov.), from the Gulf of Aqaba (Israel) was studied with light and electron microscopy and SSU rRNA gene sequencing. Clypifer cribrifer has only one type of scales, partially running up the sides of the axopodia. Plate scales [0.8-2.3 (av. 1.5)×0.6-1.8 (av. 1.2) μm] are flat, elliptical or circular, fenestrated with holes of irregular shape and have a marginal rim and a very short axial rib. The cell diameter is 3.9-9.6 (av. 6.0) μm. Molecular phylogenetic analysis robustly places C. cribrifer in the C4 clade for which the new family Clypiferidae is proposed here. This position is confirmed with the short sequences in the panacanthocystid increased regions. The morphology of the new genus has similarities to the genus Raphidocystis. The probability that another Clypifer species was described under a different name in the centrohelid literature is discussed. Clypiferidae represent the second lineage of Pterocystida, which are characterized by the presence of only tangentially oriented plate scales of one type. Possible ways of evolution of the centrohelid siliceous coverings are also discussed.
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Affiliation(s)
- Yegor Shishkin
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7/9, 199034, Saint Petersburg, Russia
| | - Daria Drachko
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7/9, 199034, Saint Petersburg, Russia.,Laboratory of Cellular & Molecular Protistology, Zoological Institute of Russian Academy of Sciences, Universitetskaya Embankment 1, 199034, Saint Petersburg, Russia
| | - Vasily V Zlatogursky
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7/9, 199034, Saint Petersburg, Russia
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Zlatogursky VV, Shɨshkin Y, Drachko D, Burki F. The long-time orphan protist Meringosphaera mediterranea Lohmann, 1902 [1903] is a centrohelid heliozoan. J Eukaryot Microbiol 2021; 68:e12860. [PMID: 34048133 DOI: 10.1111/jeu.12860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Meringosphaera is an enigmatic marine protist without clear phylogenetic affiliation, but it has long been suggested to be a chrysophyte-related autotroph. Microscopy-based reports indicate that it has a worldwide distribution, but no sequence data exist so far. We obtained the first 18S rDNA sequence for M. mediterranea (identified using light and electron microscopy) from the west coast of Sweden. Observations of living cells revealed granulated axopodia and up to 6 globular photosynthesizing bodies about 2 μm in diameter, the nature of which requires further investigation. The ultrastructure of barbed undulating spine scales and patternless plate scales with a central thickening is in agreement with previous reports. Molecular phylogenetic analysis placed M. mediterranea inside the NC5 environmental clade of Centroplasthelida (Haptista) along with additional environmental sequences, together closely related to Choanocystidae. This placement is supported by similar scales in Meringosphaera and Choanocystidae. We searched the Tara Oceans 18S V9 metabarcoding dataset, which revealed four OTUs with 94.8%-98.2% similarity, with oceanic distribution similar to that based on morphological observations. The current taxonomic position and species composition of the genus are discussed. The planktonic lifestyle of M. mediterranea contradicts the view of some authors that centrohelids enter the plankton only temporarily.
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Affiliation(s)
- Vasily V Zlatogursky
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia.,Department of Organismal Biology, Systematic Biology Program, Uppsala University, Uppsala, Sweden
| | - Yegor Shɨshkin
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia
| | - Daria Drachko
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, St. Petersburg, Russia.,Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, St. Petersburg, Russia
| | - Fabien Burki
- Department of Organismal Biology, Systematic Biology Program, Uppsala University, Uppsala, Sweden.,Science for Life Laboratory, Uppsala University, Uppsala, Sweden
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Shishkin Y, Drachko D, Zlatogursky VV. The smallest known heliozoans are the Erebor lineage (nom. clad. n.) inside Microheliella maris (Eukaryota, Diaphoretickes), with the amendation of M. maris diagnosis and description of Berkeleyaesol magnus gen. nov., comb. nov. (Eukaryota, incertae sedis). Int J Syst Evol Microbiol 2021; 71. [PMID: 33886450 DOI: 10.1099/ijsem.0.004776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A new strain of planktonic heliozoans (ZI172) belonging to the genus Microheliella (the sister group of Cryptista in Diaphoretickes), closely related to the only one known strain of Microheliella maris (CCAP 1945/1), was studied with light microscopy and SSU rRNA gene sequencing. Morphometric data obtained from 127 cells and based on 254 measurements showed that this strain represents the smallest heliozoan (1.66-3.42 µm, av. 2.56 µm) in diameter known to date and one of the smallest free-living eukaryotes. We also did morphometry for strain CCAP 1945/1. Its cell body size is 3.20-6.47 µm (av. 4.15 µm; n=141; m=282). The secondary structures of hairpin 15 of the SSU rRNA molecules were reconstructed for ZI172 and CCAP 1945/1 and they were compared The possible biochemical explanation for the smaller size of the ZI172 strain, which is smaller than the CCAP 1945/1 strain, is discussed, including all published electron micrographs of CCAP 1945/1. The necessary taxonomic work is also carried out. The diagnosis of Microheliella maris is amended and the new infraspecific clade Erebor is described to include ZI172. The measurements and systematics of the enigmatic heliozoan 'Raphidiophrys' magna O'Donoghue 1922 (non 1921; the biggest known heliozoan) are also discussed and it is transferred to the new genus Berkeleyaesol.
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Affiliation(s)
- Yegor Shishkin
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7/9, 199034, Saint Petersburg, Russia
| | - Daria Drachko
- Laboratory of Cellular & Molecular Protistology, Zoological Institute of Russian Academy of Sciences, Universitetskaya Embankment 1, 199034, Saint Petersburg, Russia.,Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7/9, 199034, Saint Petersburg, Russia
| | - Vasily V Zlatogursky
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Universitetskaya Embankment 7/9, 199034, Saint Petersburg, Russia
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13
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Drachko D, Shɨshkin Y, Zlatogursky VV. Phenotypic masquerade: Polymorphism in the life cycle of the centrohelid heliozoan Raphidiophrys heterophryoidea (Haptista: Centroplasthelida). Eur J Protistol 2020; 73:125686. [PMID: 32109646 DOI: 10.1016/j.ejop.2020.125686] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 01/29/2020] [Accepted: 02/02/2020] [Indexed: 11/29/2022]
Abstract
The life cycle of the centrohelid heliozoan Raphidiophrys heterophryoidea Zlatogursky, 2012 was studied with light and electron microscopy in clonal cultures from the type locality. The alternation of two types of trophozoites, having contrastingly different morphology, was observed. Type 1 trophozoites morphology matched the original description. Type 2 trophozoites tended to form colonies usually of 6-8 individuals, connected with cytoplasmic bridges and their cell size was noticeably bigger, namely 43-45 μm compared to 24.5 μm on average in type 1 trophozoites. Some colonies were forming stalks composed of three or four axopodia covered with scales. Spicules were lacking completely, while plate-scales differed from those of type 1 trophozoites: they had oblong-elliptical shape, larger (5.9-14.1 × 2.4-5.8 μm) size, non-branching septa always reaching scale centre, solid upper plate. The conspecificity of the two trophozoite types was confirmed with the comparison of SSU rDNA gene sequence data. Both types of trophozoites were capable of encystment and excysted individuals always were type 1 trophozoites. A new type of cyst-scales (cup-scales) was described. Transitions between cysts and the two trophozoites types were documented. The diagnosis of R. heterophryoidea was improved accordingly. The possible functions, driving forces, and taxonomic consequences of the polymorphism were discussed.
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Affiliation(s)
- Daria Drachko
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaja nab. 7/9, 199034, St. Petersburg, Russia; Laboratory of Cellular and Molecular Protistology, Zoological Institute RAS, Universitetskaja nab. 1,199034, St. Petersburg, Russia.
| | - Yegor Shɨshkin
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaja nab. 7/9, 199034, St. Petersburg, Russia
| | - Vasily V Zlatogursky
- Department of Invertebrate Zoology, Faculty of Biology, St. Petersburg State University, Universitetskaja nab. 7/9, 199034, St. Petersburg, Russia
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14
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Gerasimova EA, Plotnikov AO, Khlopko YA, Zlatogursky VV. Multiple Euryhaline Lineages of Centrohelids (Haptista: Centroplasthelida) in Inland Saline Waters Revealed with Metabarcoding. J Eukaryot Microbiol 2019; 67:223-231. [DOI: 10.1111/jeu.12776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/30/2019] [Accepted: 11/15/2019] [Indexed: 02/02/2023]
Affiliation(s)
- Elena A. Gerasimova
- Center of Shared Scientific Equipment “Persistence of Microorganisms” Institute for Cellular and Intracellular Symbiosis Ural Branch of Russian Academy of Sciences Orenburg 460000 Russia
| | - Andrey O. Plotnikov
- Center of Shared Scientific Equipment “Persistence of Microorganisms” Institute for Cellular and Intracellular Symbiosis Ural Branch of Russian Academy of Sciences Orenburg 460000 Russia
| | - Yuri A. Khlopko
- Center of Shared Scientific Equipment “Persistence of Microorganisms” Institute for Cellular and Intracellular Symbiosis Ural Branch of Russian Academy of Sciences Orenburg 460000 Russia
| | - Vasily V. Zlatogursky
- Department of Invertebrate Zoology Faculty of Biology St. Petersburg State University St. Petersburg 199034 Russia
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15
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Zlatogursky VV, Gerasimova EA, Drachko D, Klimov VI, Shɨshkin Y, Plotnikov AO. Pinjata ruminata
gen. et sp. n.—A New Member of Centrohelid Family Yogsothothidae (Haptista: Centroplasthelida) from the Brackish River. J Eukaryot Microbiol 2019; 66:862-868. [DOI: 10.1111/jeu.12737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/12/2019] [Accepted: 03/26/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Vasily V. Zlatogursky
- Department of Invertebrate Zoology Faculty of Biology St. Petersburg State University St. Petersburg 199034 Russia
| | - Elena A. Gerasimova
- Center of Shared Scientific Equipment Institute for Cellular and Intracellular Symbiosis UrB RAS Orenburg 460000 Russia
| | - Daria Drachko
- Department of Invertebrate Zoology Faculty of Biology St. Petersburg State University St. Petersburg 199034 Russia
- Laboratory of Cellular and Molecular Protistology Zoological Institute RAS St. Petersburg 199034 Russia
| | - Vladimir I. Klimov
- Department of Invertebrate Zoology Faculty of Biology St. Petersburg State University St. Petersburg 199034 Russia
| | - Yegor Shɨshkin
- Department of Invertebrate Zoology Faculty of Biology St. Petersburg State University St. Petersburg 199034 Russia
| | - Andrey O. Plotnikov
- Center of Shared Scientific Equipment Institute for Cellular and Intracellular Symbiosis UrB RAS Orenburg 460000 Russia
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