{"title":"In memoriam: Thomas Cavalier-Smith (1942–2021)","authors":"Gaytha A. Langlois, Sonja Rueckert","doi":"10.1111/jeu.13013","DOIUrl":"10.1111/jeu.13013","url":null,"abstract":"<p>Thomas Cavalier-Smith, born in London, U.K., on October 21, 1942, was a Professor of Evolutionary Biology in the Department of Zoology at the University of Oxford at the time of his death on March 19, 2021. Credited with at least 235 research works and over 20,000 citations, Cavalier-Smith was a well-known and widely respected scientist who took a bold and detailed approach to understanding major transitions in evolution, including the role of endosymbiosis. He was noted for his willingness to question theories and constantly accumulate and evaluate data, motivated by science for the sake of science. This paper reviews Thomas Cavalier-Smith's major accomplishments, examines his theoretical approaches, and provides highlights from the “Tree of Life Symposium” sponsored by the International Society of Protistologists (ISOP) and the International Society of Evolutionary Protistology (ISEP) on June 21, 2021, to celebrate Tom's life and work.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138498483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaochen Feng, Daniel Méndez-Sánchez, Wenbao Zhuang, Ran Li, Ondřej Pomahač, Ivan Čepička, Johana Rotterová, Xiaozhong Hu
{"title":"Morphology, morphogenesis, and molecular characterization of Castula specialis sp. nov. (Ciliophora, Armophorea, Metopida)","authors":"Xiaochen Feng, Daniel Méndez-Sánchez, Wenbao Zhuang, Ran Li, Ondřej Pomahač, Ivan Čepička, Johana Rotterová, Xiaozhong Hu","doi":"10.1111/jeu.13014","DOIUrl":"10.1111/jeu.13014","url":null,"abstract":"<p>The morphology, morphogenesis, and molecular phylogeny of a new metopid ciliate, <i>Castula specialis</i> sp. nov., comprising three strains from geographically distant (China, Mexico, Czech Republic) anoxic freshwater habitats, were studied based on microscopic observation of live and protargol-stained specimens as well as SSU rRNA gene sequence data. The new species is characterized as follows: size in vivo 105–220 × 25–70 μm, body oblong to elongated ellipsoidal and asymmetrical; preoral dome distinctly projecting beyond the body; 32–46 adoral membranelles; 31–52 somatic kineties; and 4–7 setae. This study brings the first morphogenetic investigation of a member of the genus <i>Castula</i>. The morphogenesis of the type population (China) of the new species proceeds as in <i>Metopus</i> spp. comprising drastic changes in body shape and a pleurotelokinetal stomatogenesis; however, the main difference is the origin of the opisthe's paroral membrane that derives from all perizonal rows and some adjacent dome kineties. Phylogenetically, the genus <i>Castula</i> is paraphyletic.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138451639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular characterization of Blastocystis spp. in Hotan Black chickens in southern Xinjiang","authors":"Xinwei Feng, Luyao Xin, Bowen Zhang, Zhichao Wang, Zhu Meng, Fuchang Yu, Meng Qi","doi":"10.1111/jeu.13012","DOIUrl":"10.1111/jeu.13012","url":null,"abstract":"<p>To determine the infection status and assess the zoonotic potential of <i>Blastocystis</i> spp. in Hotan Black chickens in southern Xinjiang, China, fecal samples were collected from 617 chickens on 18 large-scale farms. The presence of <i>Blastocystis</i> spp. was determined using polymerase chain reaction based on the small subunit rRNA (<i>SSU</i> rRNA) locus. The results revealed an overall infection rate of 26.3% (162/617). Samples from Farm 1 in Luopu County showed the highest infection rate (76.3%, 29/38). The highest and lowest infection rates were detected in the <30-day (34.4%, 43/125) and > 90-day age groups (12.4%, 11/89), respectively. The infection rate decreased with increasing age. Statistical analysis showed significant differences in the infection rates of <i>Blastocystis</i> spp. among the different sampling sites (<i>p</i> < 0.05) and age groups (<i>p</i> < 0.05). Four <i>Blastocystis</i> spp. subtypes (ST6, ST7, ST10, and ST23) were identified. The infection rates of the zoonotic subtypes, ST6 and ST7, were 3.2% (20/617) and 22.2% (137/617), respectively. The presence of <i>Blastocystis</i> spp. and zoonotic subtypes provided evidence for the potential transmission of this pathogen between Hotan Black chickens and humans, especially in animal handlers in this area.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136397686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Rhabdamoeba marina is a heterotrophic relative of chlorarachnid algae","authors":"Takashi Shiratori, Ken-ichiro Ishida","doi":"10.1111/jeu.13010","DOIUrl":"10.1111/jeu.13010","url":null,"abstract":"<p><i>Rhabdamoeba marina</i> is a unique and poorly reported amoeba with an uncertain phylogenetic position. We successfully cultured <i>R. marina</i> from coastal seawater in Japan and performed a molecular phylogenetic analysis using the small subunit ribosomal RNA (SSU rRNA) gene sequence. Our phylogenetic analysis showed that <i>R. marina</i> branched as a basal lineage of Chlorarachnea, a group of marine photosynthetic algae belonging to the phylum Cercozoa within the supergroup Rhizaria. By comparing the ecological and morphological characteristics of <i>R. marina</i> with those of photosynthetic chlorarachneans and other cercozoans, we gained insight into the evolution and acquisition of plastids in Chlorarachnida.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 2","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71521714","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magdaléna Pavlátová, Pavla Hanousková, Ivan Čepička
{"title":"Anaeramoeba pumila sp. nov. and Anaeramoeba sp. OCE22C represent two novel types of symbiosis of Anaeramoebae and prokaryotes","authors":"Magdaléna Pavlátová, Pavla Hanousková, Ivan Čepička","doi":"10.1111/jeu.13008","DOIUrl":"10.1111/jeu.13008","url":null,"abstract":"<p>Anaeramoebae is a recently described phylum of anaerobic, marine amoebae, and amoeboflagellates belonging to the Metamonada supergroup. So far, six species have been described based on light microscopic morphology and sequences of the SSU rRNA gene. Here we present three new strains of <i>Anaeramoeba</i> with a description of their morphology, ultrastructure, and phylogenetic position based on the analysis of SSU rRNA gene sequences. Two of the strains represent a new species, <i>Anaeramoeba pumila</i> sp. nov., that has the smallest cells of all known <i>Anaeramoeba</i> species, and one that represents a species from the newly recognized <i>Anaeramoeba flamelloides</i> complex. Anaeramoebae are known to have a syntrophic relationship with prokaryotes. Our strains display two novel, remarkable types of symbioses, previously unknown from Anaeramoebae.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jeu.13008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71482149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yong Chi, Danxu Tang, Jingtao Lei, Fan Wei, Saleh A. Al-Farraj, William A. Bourland, Zigui Chen
{"title":"Highly divergent morphology but a close molecular phylogenetic relationship between two little-known ciliate genera Actinobolina and Papillorhabdos (Protozoa: Ciliophora: Litostomatea) with description of two new species","authors":"Yong Chi, Danxu Tang, Jingtao Lei, Fan Wei, Saleh A. Al-Farraj, William A. Bourland, Zigui Chen","doi":"10.1111/jeu.13007","DOIUrl":"10.1111/jeu.13007","url":null,"abstract":"<p>Free-living litostomatean ciliates, prominent microeukaryote predators commonly encountered in freshwater and marine habitats, play vital roles in maintaining energy flow and nutrient cycles. Nevertheless, understanding their biodiversity and phylogenetic relationships remains challenging due to insufficient morphological information and molecular data. As a new contribution to this group, three haptorian ciliates, including two new species (<i>Actinobolina bivacuolata</i> sp. nov. and <i>Papillorhabdos foissneri</i> sp. nov.) and the insufficiently described type species, <i>Actinobolina radians</i>, were isolated from wetlands around Lake Weishan, China and investigated by a combination of living morphology, stained preparations, and 18S rRNA gene sequence data. An illustrated key of the valid species within the two genera is provided. In addition, we reveal the phylogenetic positions of these two genera for the first time. Although they differ in all key morphologic characters such as general appearance (ellipsoidal with numerous tentacles vs. cylindrical), extrusomes (stored in tentacles vs. anchored to pellicle), circumoral kinety (present vs. absent), composition of somatic kineties (kinetosome clusters vs. monokinetids), and number of dorsal brush rows (1 vs. 4), they both cluster in a fully supported clade in the phylogenetic tree, which indicates that the biodiversity and additional molecular markers of this group need further exploration.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"54229275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tiia Luostarinen, Sofia Ribeiro, Heike H. Zimmermann, Anna B. Kvorning, Maija Heikkilä
{"title":"Single-cell DNA from West Greenland marine sediments suggests presence of Protoperidinium tricingulatum in the Arctic","authors":"Tiia Luostarinen, Sofia Ribeiro, Heike H. Zimmermann, Anna B. Kvorning, Maija Heikkilä","doi":"10.1111/jeu.13005","DOIUrl":"10.1111/jeu.13005","url":null,"abstract":"<p>Spiny brown dinoflagellate cysts are commonly used as sea-ice indicators in the Arctic, but their biological affinities are not well known. We present the first indication of hitherto temperate <i>Protoperidinium tricingulatum</i> in the Arctic based on single-cell LSU rDNA sequencing from sediments of the Disko Bay-Vaigat Sound, West Greenland. The morphological similarity of the sequenced cyst morphotype to the sea-ice indicator <i>Islandinium</i>? <i>cezare</i> morphotype 1 is striking. The morphology of the isolated cysts, as well as those observed in the total cyst assemblage following standard palynological preparation, both resemble either <i>I.? cezare</i> morphotype 1 or <i>P. tricingulatum</i>, suggesting that the specimens may in fact be close morphological variants of the same species. In addition, nine LSU rDNA sequences were obtained from morphological variants assigned to <i>Islandinium minutum</i> s.l.: including both subspecies <i>minutum</i> and subspecies <i>barbatum</i>. The two subspecies could not be differentiated based on partial LSU rDNA sequencing. Overall, Arctic spiny brown dinoflagellate cyst species may be morphologically more diverse and taxonomically more complex than shown earlier and further genetic and morphological studies are needed. Importantly, the value of cysts as palaeoecological indicators depends on a sound understanding of their biological affinity and taxonomy.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jeu.13005","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"50158085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maksim Melekhin, Alexey Potekhin, Eleni Gentekaki, Chitchai Chantangsi
{"title":"Paramecium (Oligohymenophorea, Ciliophora) diversity in Thailand sheds light on the genus biogeography and reveals new phylogenetic lineages","authors":"Maksim Melekhin, Alexey Potekhin, Eleni Gentekaki, Chitchai Chantangsi","doi":"10.1111/jeu.13004","DOIUrl":"10.1111/jeu.13004","url":null,"abstract":"<p><i>Paramecium</i> (Ciliophora, Oligohymenophorea) is a good model to study ciliate biogeography. Extensive sampling mainly in northern hemisphere has led to 16 valid morphological species description thus far. However, a majority of hard-to-reach regions, including South East Asia, are underinvestigated. Our study combined traditional morphological and molecular approaches to reveal the biodiversity of <i>Paramecium</i> in Thailand from more than 110 samples collected in 10 provinces. Representatives of seven morphological species were identified from our collection, including the rare species, such as <i>P. gigas</i> and <i>P. jenningsi</i>. Additionally, we detected five different sibling species of the <i>P. aurelia</i> complex, described a new cryptic species <i>P. hiwatashii</i> n. sp. phylogenetically related to <i>P. caudatum,</i> and discovered a potentially new genetic species of the <i>P. bursaria</i> species complex. We also documented a variety of bacterial cytoplasmic symbionts from at least nine monoclonal cultures of <i>Paramecium</i>.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41235804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Elizabeth J. Weston, Yana Eglit, Alastair G. B. Simpson
{"title":"Kaonashia insperata gen. et sp. nov., a eukaryotrophic flagellate, represents a novel major lineage of heterotrophic stramenopiles","authors":"Elizabeth J. Weston, Yana Eglit, Alastair G. B. Simpson","doi":"10.1111/jeu.13003","DOIUrl":"10.1111/jeu.13003","url":null,"abstract":"<p>Eukaryotrophic protists are ecologically significant and possess characteristics key to understanding the evolution of eukaryotes; however, they remain poorly studied, due partly to the complexities of maintaining predator–prey cultures. <i>Kaonashia insperata</i>, gen. nov., et sp. nov., is a free-swimming biflagellated eukaryotroph with a conspicuous ventral groove, a trait observed in distantly related lineages across eukaryote diversity. Di-eukaryotic (predator–prey) cultures of <i>K</i>. <i>insperata</i> with three marine algae (<i>Isochrysis galbana</i>, <i>Guillardia theta</i>, and <i>Phaeodactylum tricornutum</i>) were established by single-cell isolation. Growth trials showed that the studied <i>K</i>. <i>insperata</i> clone grew particularly well on <i>G</i>. <i>theta</i>, reaching a peak abundance of 1.0 × 10<sup>5</sup> ± 4.0 × 10<sup>4</sup> cells ml<sup>−1</sup>. Small-subunit ribosomal DNA phylogenies infer that <i>K</i>. <i>insperata</i> is a stramenopile with moderate support; however, it does not fall within any well-defined phylogenetic group, including environmental sequence clades (e.g. MASTs), and its specific placement remains unresolved. Electron microscopy shows traits consistent with stramenopile affinity, including mastigonemes on the anterior flagellum and tubular mitochondrial cristae. <i>Kaonashia insperata</i> may represent a novel major lineage within stramenopiles, and be important for understanding the evolutionary history of the group. While heterotrophic stramenopile flagellates are considered to be predominantly bacterivorous, eukaryotrophy may be relatively widespread amongst this assemblage.</p>","PeriodicalId":15672,"journal":{"name":"Journal of Eukaryotic Microbiology","volume":"71 1","pages":""},"PeriodicalIF":2.2,"publicationDate":"2023-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jeu.13003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41124172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}