Testate amoebae are a polyphyletic and highly diverse group of unicellular protists, inhabiting various habitats and successfully used as indicators of property of environmental variables, providing information on hydrology, pH and pollution of ecosystems. However, despite numerous studies, there is still a lack of data regarding their species diversity, geographical distribution and population dynamics in various habitats from previously unexplored or poorly investigated regions such as Mongolia. In this study, we describe the morphology and morphometry of a new genus and four new species: Armatura murmillo gen. nov., sp. nov., Trinema lenticularis sp. nov., T. parmularius sp. nov. and T. scutarius sp. nov., derived from peat cores extracted from two fens in northern Mongolia. We provide one of the first case studies of testate amoebae from Mongolia, documenting 64 taxa. We also provide information on the morphology and variability of four lesser known species: Centropyxis lapponica, Hyalosphenia insecta, Pyxidicula ornata and Schoenbornia smithi.
{"title":"Morphological and morphometric investigations on testate amoebae from Mongolia with descriptions of a new genus and four new species.","authors":"Dominika Łuców, Ferry Siemensma, Dashtseren Avirmed, Milena Obremska, Michał Słowiński, Izabela Zawiska","doi":"10.1016/j.ejop.2024.126128","DOIUrl":"https://doi.org/10.1016/j.ejop.2024.126128","url":null,"abstract":"<p><p>Testate amoebae are a polyphyletic and highly diverse group of unicellular protists, inhabiting various habitats and successfully used as indicators of property of environmental variables, providing information on hydrology, pH and pollution of ecosystems. However, despite numerous studies, there is still a lack of data regarding their species diversity, geographical distribution and population dynamics in various habitats from previously unexplored or poorly investigated regions such as Mongolia. In this study, we describe the morphology and morphometry of a new genus and four new species: Armatura murmillo gen. nov., sp. nov., Trinema lenticularis sp. nov., T. parmularius sp. nov. and T. scutarius sp. nov., derived from peat cores extracted from two fens in northern Mongolia. We provide one of the first case studies of testate amoebae from Mongolia, documenting 64 taxa. We also provide information on the morphology and variability of four lesser known species: Centropyxis lapponica, Hyalosphenia insecta, Pyxidicula ornata and Schoenbornia smithi.</p>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"97 ","pages":"126128"},"PeriodicalIF":1.9,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142946883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ejop.2024.126121
Stefano Lometto , Daniela Sparvoli , Gabriele Malengo , Thomas Heimerl , Georg K.A. Hochberg
The mitochondrial citrate synthase (mCS) purified from the ciliate Tetrahymena thermophila has been reported to form intermediate-filament-like structures during conjugation and to self-assemble into fibers when recombinantly expressed. This would represent a rare example of a tractable and recent origin of a novel cytoskeletal element. In an attempt to investigate the evolutionary emergence of this behavior, we re-investigated the ability of Tetrahymena’s mCS to form filaments in vivo. Using strep-tagged mCS in Tetrahymena and monoclonal antibodies, we found no evidence of filamentous structures during conjugation or starvation. Extensive biochemical characterization of mCS revealed that the self-assembly of recombinant protein is triggered by a specific chemical moiety shared by MES and HEPES buffers used in previous studies. The absence of indicative phenotypes in fiber-deficient GFP-tagged mutants indicates that Tetrahymena mCS did not evolve a structural role in sexual reproduction or metabolic regulation.
据报道，从嗜热四膜虫（Tetrahymena thermophila）中纯化的线粒体柠檬酸合成酶（mCS）可在连接过程中形成类似中间膜的结构，并在重组表达时自组装成纤维。这代表了一种新型细胞骨架元素的可控和近期起源的罕见实例。为了研究这种行为在进化过程中的出现，我们重新研究了四膜虫的mCS在体内形成细丝的能力。利用链球菌标记的四膜虫 mCS 和单克隆抗体，我们发现在连接或饥饿过程中都没有丝状结构的迹象。对 mCS 进行广泛的生化鉴定后发现，重组蛋白的自组装是由先前研究中使用的 MES 和 HEPES 缓冲液共有的一种特定化学分子引发的。在纤维缺失的GFP标记突变体中没有出现指示性表型，这表明四膜虫mCS在有性生殖或新陈代谢调节中没有演化出结构性作用。
{"title":"The mitochondrial citrate synthase from Tetrahymena thermophila does not form an intermediate filament","authors":"Stefano Lometto , Daniela Sparvoli , Gabriele Malengo , Thomas Heimerl , Georg K.A. Hochberg","doi":"10.1016/j.ejop.2024.126121","DOIUrl":"10.1016/j.ejop.2024.126121","url":null,"abstract":"<div><div>The mitochondrial citrate synthase (mCS) purified from the ciliate <em>Tetrahymena thermophila</em> has been reported to form intermediate-filament-like structures during conjugation and to self-assemble into fibers when recombinantly expressed. This would represent a rare example of a tractable and recent origin of a novel cytoskeletal element. In an attempt to investigate the evolutionary emergence of this behavior, we re-investigated the ability of <em>Tetrahymena</em>’s mCS to form filaments in vivo. Using strep-tagged mCS in <em>Tetrahymena</em> and monoclonal antibodies, we found no evidence of filamentous structures during conjugation or starvation. Extensive biochemical characterization of mCS revealed that the self-assembly of recombinant protein is triggered by a specific chemical moiety shared by MES and HEPES buffers used in previous studies. The absence of indicative phenotypes in fiber-deficient GFP-tagged mutants indicates that <em>Tetrahymena</em> mCS did not evolve a structural role in sexual reproduction or metabolic regulation.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126121"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142461230","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Kingdom of Bhutan in the Eastern Himalayas harbors a rich biodiversity. However, its detailed documentation still needs to be created, including not only macroorganisms but also protists. In the present study, as many as 105 taxa of testate amoebae were identified and directly counted in soil suspension samples collected from the wetlands of the Gangtey-Phobji Valley (generally Phobjikha), Wangdue Phodrang district. The most dominant were cosmopolitan species, e.g., Euglypha rotunda, Trinema lineare, T. complanatum, T. enchelys, Phryganella acropodia, and Plagiopyxis declivis. However, some taxa such as Centropyxis deflandriana, C. stenodeflandriana, Hoogenraadia cf. humicola, Pareuglypha reticulata, and Sphenoderia chardezi have a geographically restricted distribution and/or are considered rare. Some specimens could not be assigned to already described species (Centropyxis dentata sp. nov. and Difflugia fusiforma sp. nov.) or were highly similar to known species but differed in size or other taxonomically important characteristics (e.g., Hoogenraadia cf. humicola and Planhoogenraadia sp.). To our knowledge, this study is the first to present a comprehensive list of testate amoebae from Bhutan, including some new and rare species. The discovery of a remarkable diversity of testate amoebae in only a few soil samples suggests that this remote and largely unexplored region likely harbors many more intriguing species.
{"title":"Testate amoebae from the wetlands of the Phobjikha Valley of Bhutan, the Eastern Himalayas","authors":"Manfred Wanner , Ferry Siemensma , Indra Prasad Acharja , Jigme Tshering , Pema Khandu , Santa Lal Gajmer , Chöki Gyeltshen , Tshering Dorji , Kinley Tenzin , Satoshi Shimano","doi":"10.1016/j.ejop.2024.126125","DOIUrl":"10.1016/j.ejop.2024.126125","url":null,"abstract":"<div><div>The Kingdom of Bhutan in the Eastern Himalayas harbors a rich biodiversity. However, its detailed documentation still needs to be created, including not only macroorganisms but also protists. In the present study, as many as 105 taxa of testate amoebae were identified and directly counted in soil suspension samples collected from the wetlands of the Gangtey-Phobji Valley (generally Phobjikha), Wangdue Phodrang district. The most dominant were cosmopolitan species, e.g., <em>Euglypha rotunda</em>, <em>Trinema lineare</em>, <em>T. complanatum</em>, <em>T. enchelys</em>, <em>Phryganella acropodia</em>, and <em>Plagiopyxis declivis</em>. However, some taxa such as <em>Centropyxis deflandriana, C. stenodeflandriana</em>, <em>Hoogenraadia</em> cf<em>. humicola</em>, <em>Pareuglypha reticulata</em>, and <em>Sphenoderia chardezi</em> have a geographically restricted distribution and/or are considered rare. Some specimens could not be assigned to already described species (<em>Centropyxis dentata</em> sp. nov. and <em>Difflugia fusiforma</em> sp. nov.) or were highly similar to known species but differed in size or other taxonomically important characteristics (e.g., <em>Hoogenraadia</em> cf. <em>humicola</em> and <em>Planhoogenraadia</em> sp.). To our knowledge, this study is the first to present a comprehensive list of testate amoebae from Bhutan, including some new and rare species. The discovery of a remarkable diversity of testate amoebae in only a few soil samples suggests that this remote and largely unexplored region likely harbors many more intriguing species.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126125"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142617431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new urostylid ciliate, Holostichides (Holostichides) parachardezi, collected from a Chinese tropical city, was studied using morphological and molecular methods. Diagnostic features of the new species include: size 140–180 × 30–60 μm in vivo; 25–43 macronuclear nodules; colourless cortical granules; three to six frontoterminal cirri; a midventral complex composed of seven to eleven cirral pairs and one midventral row of five to eleven cirri; four bipolar dorsal kineties and six to nine caudal cirri in four groups; and a terrestrial habitat. Its ontogenesis follows the typical Holostichides mode in that (1) the proximal portion of the parental adoral zone of membranelles is partly renewed and the opisthe’s oral primordium originates very close to the midventral complex; (2) the last anlage n generates the frontoterminal cirral row, and the midventral complex is formed from anlage IV to n − 1; and (3) both marginal rows and dorsal kinety anlagen develop within the parental rows. The present SSU rDNA phylogenies corroborated the monophyly of the genus Holostichides.
{"title":"Morphology, morphogenesis, and molecular phylogeny of Holostichides (Holostichides) parachardezi nov. spec. (Ciliophora, Hypotrichia, Urostylida), a new soil ciliate from China","authors":"Ziyan Liu, Kexin Wang, Chengliang Zhang, Yuwen Jiang, Ranran Song, Tengyue Zhang, Fengchao Li","doi":"10.1016/j.ejop.2024.126124","DOIUrl":"10.1016/j.ejop.2024.126124","url":null,"abstract":"<div><div>A new urostylid ciliate, <em>Holostichides</em> (<em>Holostichides</em>) <em>parachardezi</em>, collected from a Chinese tropical city, was studied using morphological and molecular methods. Diagnostic features of the new species include: size 140–180 × 30–60 μm in vivo; 25–43 macronuclear nodules; colourless cortical granules; three to six frontoterminal cirri; a midventral complex composed of seven to eleven cirral pairs and one midventral row of five to eleven cirri; four bipolar dorsal kineties and six to nine caudal cirri in four groups; and a terrestrial habitat. Its ontogenesis follows the typical <em>Holostichides</em> mode in that (1) the proximal portion of the parental adoral zone of membranelles is partly renewed and the opisthe’s oral primordium originates very close to the midventral complex; (2) the last anlage <em>n</em> generates the frontoterminal cirral row, and the midventral complex is formed from anlage IV to <em>n</em> − 1; and (3) both marginal rows and dorsal kinety anlagen develop within the parental rows. The present SSU rDNA phylogenies corroborated the monophyly of the genus <em>Holostichides</em>.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126124"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142646335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ejop.2024.126119
Megan Gross , Ľubomír Rajter , Frédéric Mahé , David Bass , Cédric Berney , Nicolas Henry , Colomban de Vargas , Micah Dunthorn
Short-branch Microsporidia were previously shown to form a basal grade within the expanded Microsporidia clade and to branch near the classical, long-branch Microsporidia. Although they share simpler versions of some morphological characteristics, they do not show accelerated evolutionary rates, making them ideal candidates to study the evolutionary trajectories that have led to long-branch microsporidian unique characteristics. However, most sequences assigned to the short-branch Microsporidia are undescribed, novel environmental lineages for which the identification requires knowledge of where they can be found. To direct future isolation, we used the EukBank database of the global UniEuk initiative that contains the majority of the publicly available environmental V4 SSU rRNA gene sequences of protists. The curated OTU table and corresponding metadata were used to evaluate the occurrence of short-branch Microsporidia across freshwater, hypersaline, marine benthic, marine pelagic, and terrestrial environments. Presence–absence analyses infer that short-branch Microsporidia are most abundant in freshwater and terrestrial environments, and alpha- and beta-diversity measures indicate that focusing our sampling effort on these two environments would cover a large part of their overall diversity. These results can be used to coordinate future isolation and sampling campaigns to better understand the enigmatic evolution of microsporidians’ unique characteristics.
{"title":"O short-branch Microsporidia, where art thou? Identifying diversity hotspots for future sampling","authors":"Megan Gross , Ľubomír Rajter , Frédéric Mahé , David Bass , Cédric Berney , Nicolas Henry , Colomban de Vargas , Micah Dunthorn","doi":"10.1016/j.ejop.2024.126119","DOIUrl":"10.1016/j.ejop.2024.126119","url":null,"abstract":"<div><div>Short-branch Microsporidia were previously shown to form a basal grade within the expanded Microsporidia clade and to branch near the classical, long-branch Microsporidia. Although they share simpler versions of some morphological characteristics, they do not show accelerated evolutionary rates, making them ideal candidates to study the evolutionary trajectories that have led to long-branch microsporidian unique characteristics. However, most sequences assigned to the short-branch Microsporidia are undescribed, novel environmental lineages for which the identification requires knowledge of where they can be found. To direct future isolation, we used the EukBank database of the global UniEuk initiative that contains the majority of the publicly available environmental V4 SSU rRNA gene sequences of protists. The curated OTU table and corresponding metadata were used to evaluate the occurrence of short-branch Microsporidia across freshwater, hypersaline, marine benthic, marine pelagic, and terrestrial environments. Presence–absence analyses infer that short-branch Microsporidia are most abundant in freshwater and terrestrial environments, and alpha- and beta-diversity measures indicate that focusing our sampling effort on these two environments would cover a large part of their overall diversity. These results can be used to coordinate future isolation and sampling campaigns to better understand the enigmatic evolution of microsporidians’ unique characteristics.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126119"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142427040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ejop.2024.126126
Valdirley de Souza Lima, Franciane Cedrola, Millke Jasmine Arminini Morales, Vera Nisaka Solferini
Rumen ciliates constitute a highly diverse group within the subclass Trichostomatia. They are known for their symbiotic relationship with ruminant hosts and their pivotal role in digestive metabolism. This review presents a historical analysis of research on rumen ciliate metabolism, since the earliest studies, based on in vitro and in situ experiments, as well as molecular studies, initially relying on Sanger sequencing, and more recently, next-generation sequencing techniques. Finally, the paper discusses future approaches that may be useful for elucidating the metabolic profile of various taxa of rumen ciliates.
{"title":"Disentangling the metabolic profile of rumen ciliates: A historical perspective and future directions","authors":"Valdirley de Souza Lima, Franciane Cedrola, Millke Jasmine Arminini Morales, Vera Nisaka Solferini","doi":"10.1016/j.ejop.2024.126126","DOIUrl":"10.1016/j.ejop.2024.126126","url":null,"abstract":"<div><div>Rumen ciliates constitute a highly diverse group within the subclass Trichostomatia. They are known for their symbiotic relationship with ruminant hosts and their pivotal role in digestive metabolism. This review presents a historical analysis of research on rumen ciliate metabolism, since the earliest studies, based on in vitro and in situ experiments, as well as molecular studies, initially relying on Sanger sequencing, and more recently, next-generation sequencing techniques. Finally, the paper discusses future approaches that may be useful for elucidating the metabolic profile of various taxa of rumen ciliates.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126126"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142582620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ejop.2024.126123
Dmytro Leontyev , Edvin Johannesen , Gabriel Moreno , Iryna Yatsiuk , Martin Schnittler
The paper describes a new myxomycete species, Trichia tuberculata, from the Ecuadorian cloud forest. The phylogeny constructed with nuclear 18S rDNA and mitochondrial 17S rDNA sequences indicates that the taxon is closely related to recently described species T. acetocorticola, T. nubila, and T. pinicola, all within the T. botrytis complex. The morphology of the inner peridium surface and capillitium also aligns T. tuberculata with these species. However, the distinctive tuberculate peridium, short elater tips, and perhaps the distribution range (so far found in the equatorial zone only) distinguish T. tuberculata from related taxa.
本文描述了厄瓜多尔云雾林中的一个新菌类--Trichia tuberculata。用核 18S rDNA 和线粒体 17S rDNA 序列构建的系统发生表明，该分类群与最近描述的物种 T. acetocorticola、T. nubila 和 T. pinicola 关系密切，它们都属于 T. botrytis 复合体。T. tuberculata 与这些物种的包被内表面和毛细管的形态也一致。然而，独特的瘤状包被、短的叶尖以及分布范围（迄今为止仅在赤道地区发现）可能会将 T. tuberculata 与相关类群区分开来。
{"title":"A new species of the Trichia botrytis complex from the cloud forest in Ecuador","authors":"Dmytro Leontyev , Edvin Johannesen , Gabriel Moreno , Iryna Yatsiuk , Martin Schnittler","doi":"10.1016/j.ejop.2024.126123","DOIUrl":"10.1016/j.ejop.2024.126123","url":null,"abstract":"<div><div>The paper describes a new myxomycete species, <em>Trichia tuberculata</em>, from the Ecuadorian cloud forest. The phylogeny constructed with nuclear 18S rDNA and mitochondrial 17S rDNA sequences indicates that the taxon is closely related to recently described species <em>T. acetocorticola</em>, <em>T. nubila</em>, and <em>T. pinicola</em>, all within the <em>T. botrytis</em> complex. The morphology of the inner peridium surface and capillitium also aligns <em>T. tuberculata</em> with these species. However, the distinctive tuberculate peridium, short elater tips, and perhaps the distribution range (so far found in the equatorial zone only) distinguish <em>T. tuberculata</em> from related taxa.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126123"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142638722","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ejop.2024.126120
Sandra C. Craveiro , Mariana S. Pandeirada , Øjvind Moestrup , António J. Calado
The fine-structural organization of the protoperidiniacean Kolkwitziella acuta was examined by SEM and TEM. Serial sections of five cells of K. acuta were used to study the architecture of basal bodies and associated roots, the pusular system, and the feeding apparatus. The basal bodies were inserted 1 µm apart at an angle of ca. 80°, and displayed the typical peridinioid features of associating with two roots each and having a layered connective linking the longitudinal microtubular root to the transverse striated root. The transverse flagellar canal was associated with a ‘sac pusule’, while the longitudinal flagellar canal was linked, via a pusule canal surrounded by a conspicuous layer of striated material, to a collecting chamber from which ca. 40 pusular tubes radiated. An extruded pallium was present, associated with a microtubular strand (the MSP) that extended anteriorly and progressively separated into six or seven groups of microtubules, with electron-opaque vesicles present along the MSP. A prominent striated collar surrounded the exit area of the pallium and was connected to the striated collars of both the transverse and longitudinal flagellar canals. The partial nuclear-encoded LSU rDNA sequence confirmed the identification as K. acuta. The currently known fine-structural features of pallium-feeding Protoperidiniaceae are summarized.
{"title":"Architecture of the flagellar apparatus and related structures in Kolkwitziella acuta: Towards a fine-structural characterization of pallium-feeding dinoflagellates (Protoperidiniaceae)","authors":"Sandra C. Craveiro , Mariana S. Pandeirada , Øjvind Moestrup , António J. Calado","doi":"10.1016/j.ejop.2024.126120","DOIUrl":"10.1016/j.ejop.2024.126120","url":null,"abstract":"<div><div>The fine-structural organization of the protoperidiniacean <em>Kolkwitziella acuta</em> was examined by SEM and TEM. Serial sections of five cells of <em>K. acuta</em> were used to study the architecture of basal bodies and associated roots, the pusular system, and the feeding apparatus. The basal bodies were inserted 1 µm apart at an angle of ca. 80°, and displayed the typical peridinioid features of associating with two roots each and having a layered connective linking the longitudinal microtubular root to the transverse striated root. The transverse flagellar canal was associated with a ‘sac pusule’, while the longitudinal flagellar canal was linked, via a pusule canal surrounded by a conspicuous layer of striated material, to a collecting chamber from which ca. 40 pusular tubes radiated. An extruded pallium was present, associated with a microtubular strand (the MSP) that extended anteriorly and progressively separated into six or seven groups of microtubules, with electron-opaque vesicles present along the MSP. A prominent striated collar surrounded the exit area of the pallium and was connected to the striated collars of both the transverse and longitudinal flagellar canals. The partial nuclear-encoded LSU rDNA sequence confirmed the identification as <em>K. acuta</em>. The currently known fine-structural features of pallium-feeding Protoperidiniaceae are summarized.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126120"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01Epub Date: 2024-11-28DOI: 10.1016/j.ejop.2024.126127
Jaroslav Kubín, Josef Juráň
This review aims to compile sparse information on the ecology of freshwater heterotrophic euglenoids and synthesize the main phenomena and hypotheses from published results. Apparently, heterotrophic euglenoids play a very important role in the nutrient flow of water ecosystems and are irreplaceable heterotrophic contributors in benthic communities, as their total biomass is by far the largest among heterotrophic flagellates. Even though they are obviously a very crucial part of the diversity of freshwater heterotrophic protists, and likely the most represented (in terms of biovolume) group of heterotrophic flagellates, there have been only a few attempts to elucidate their ecological preferences, roles, niches, and importance. They exhibit three nutrition modes-bacterivory, eukaryovory, and osmotrophy-which are strategies closely related to their taxonomical groupings and phylogenetic positions. Unfortunately, the phylogeny of the majority of the species remains unknown, similar to their autecology. There are major problems with the quantitative research methodologies, which is a big challenge for future research to improve.
{"title":"Ecology of free-living freshwater heterotrophic euglenoids: A summarizing review.","authors":"Jaroslav Kubín, Josef Juráň","doi":"10.1016/j.ejop.2024.126127","DOIUrl":"10.1016/j.ejop.2024.126127","url":null,"abstract":"<p><p>This review aims to compile sparse information on the ecology of freshwater heterotrophic euglenoids and synthesize the main phenomena and hypotheses from published results. Apparently, heterotrophic euglenoids play a very important role in the nutrient flow of water ecosystems and are irreplaceable heterotrophic contributors in benthic communities, as their total biomass is by far the largest among heterotrophic flagellates. Even though they are obviously a very crucial part of the diversity of freshwater heterotrophic protists, and likely the most represented (in terms of biovolume) group of heterotrophic flagellates, there have been only a few attempts to elucidate their ecological preferences, roles, niches, and importance. They exhibit three nutrition modes-bacterivory, eukaryovory, and osmotrophy-which are strategies closely related to their taxonomical groupings and phylogenetic positions. Unfortunately, the phylogeny of the majority of the species remains unknown, similar to their autecology. There are major problems with the quantitative research methodologies, which is a big challenge for future research to improve.</p>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"126127"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142791344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.ejop.2024.126122
Limin Jiang , Qianhui Sun , Xiaoxuan Zhu , Hunter N. Hines , Xiaozhong Hu
Ciliates of the class Prostomatea show a broad spectrum of feeding strategies and often occur abundantly in various aquatic habitats, playing a vital role in the biogeochemical cycle. Due to their small cell size and simple structure, prostomateans were considered to be a group with a lower degree of morphological differentiation for a long time. However, recent research suggests that the diversity of this group of ciliates is higher than previously thought. In the present study, three prostomateans, collected from different localities in China and classified into three families, were examined using morphological and phylogenetic techniques. Our analyses revealed two new species, Metacystis multitricha sp. nov. and Apolagynus spiralis sp. nov., and suggested a transfer of Prorodon abietum Penard, 1922 to the genus Pelagothrix. Phylogenetic analyses corroborated the morphological classifications of the three species into the families Metacystidae, Lagynusidae, and Holophryidae, respectively, demonstrating that their diagnostic characteristics bear an evolutionary signal at the family level.
{"title":"Morphology and molecular phylogeny of Pelagothrix abietum (Penard, 1922) comb. nov. and two new Metacystis and Apolagynus species (Ciliophora, Prostomatea)","authors":"Limin Jiang , Qianhui Sun , Xiaoxuan Zhu , Hunter N. Hines , Xiaozhong Hu","doi":"10.1016/j.ejop.2024.126122","DOIUrl":"10.1016/j.ejop.2024.126122","url":null,"abstract":"<div><div>Ciliates of the class Prostomatea show a broad spectrum of feeding strategies and often occur abundantly in various aquatic habitats, playing a vital role in the biogeochemical cycle. Due to their small cell size and simple structure, prostomateans were considered to be a group with a lower degree of morphological differentiation for a long time. However, recent research suggests that the diversity of this group of ciliates is higher than previously thought. In the present study, three prostomateans, collected from different localities in China and classified into three families, were examined using morphological and phylogenetic techniques. Our analyses revealed two new species, <em>Metacystis multitricha</em> sp. nov. and <em>Apolagynus spiralis</em> sp. nov., and suggested a transfer of <em>Prorodon abietum</em> Penard, 1922 to the genus <em>Pelagothrix</em>. Phylogenetic analyses corroborated the morphological classifications of the three species into the families Metacystidae, Lagynusidae, and Holophryidae, respectively, demonstrating that their diagnostic characteristics bear an evolutionary signal at the family level.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"96 ","pages":"Article 126122"},"PeriodicalIF":1.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142568197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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