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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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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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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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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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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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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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On the phylogenetic position of the genus Raphidocystis (Haptista: Centroplasthelida) with notes on the dimorphism in centrohelid life cycle. Eur J Protistol 2018; 64:82-90. [DOI: 10.1016/j.ejop.2018.03.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2017] [Revised: 03/24/2018] [Accepted: 03/29/2018] [Indexed: 01/27/2023]
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