European journal of protistology最新文献

{"title":"Two new species of the genus Leptomyxa (Goodey, 1915) – Leptomyxa botanica n. sp. and Leptomyxa monrepos n. sp. from the soil habitats of Northwestern Russia","authors":"Nikita S. Kulishkin ,&nbsp;Alexey V. Smirnov ,&nbsp;David J. Patterson","doi":"10.1016/j.ejop.2023.126028","DOIUrl":"10.1016/j.ejop.2023.126028","url":null,"abstract":"<div><p>Amoebae of the genus <em>Leptomyxa</em> have variable morphologies and can only be reliably identified using molecular data. However, species distinction based on the 18S rRNA gene sequence is difficult due to the very low level of sequence divergence among morphologically different species. The database for other genes is much smaller, and genomic data on <em>Leptomyxa</em> is almost absent. In this study, we describe two new terrestrial species of the genus <em>Leptomyxa</em> isolated from Northwestern Russia, <em>Leptomyxa botanica</em> n. sp. and <em>Leptomyxa monrepos</em> n. sp. Both species easily adopt an expanded fan-shaped form and have a complex structure of the nucleolar material. Phylogenetic analyses show a derived status of these two species. They form a clade with <em>Leptomyxa valladaresi</em>. Our tree confirms that the 18S rRNA gene sequences of <em>Leptomyxa</em> species are split into two large clades. The morphological synapomorphies of these clades are not obvious. This analysis is complicated by the lack of reliable morphological data on many sequenced strains and probable misidentification of some isolates.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89717416","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}

{"title":"Morphological, ontogenetic, and phylogenetic research of a poorly known non-dorsomarginalian ciliate: Erniella filiformis Foissner, 1987 (Protista, Ciliophora, Hypotrichia)","authors":"Yurui Wang,&nbsp;Jingyi Wang,&nbsp;Banghe Wang,&nbsp;Kunwu Wang,&nbsp;Chen Shao","doi":"10.1016/j.ejop.2023.126031","DOIUrl":"10.1016/j.ejop.2023.126031","url":null,"abstract":"<div><p><em>Erniella</em> Foissner, 1987 is a poorly known genus with its available information limited solely to morphological characteristics. In this study, the type species <em>E. filiformis</em>, isolated from highly saline water in China, was investigated for morphology, morphogenesis, and phylogeny based on small subunit ribosomal DNA sequences. The main characteristic events during morphogenesis in <em>Erniella filiformis</em> are as follows: (1) in the proter, only the posterior part of the parental adoral zone is renewed and undulating membranes anlage is formed from the dedifferentiation of the old structure; (2) the oral primordium is formed intrakinetally in the opisthe; (3) frontoventral-transverse cirral anlagen II–IV develop in the primary mode, anlage V develops intrakinetally in the proter; and (4) the right frontoventral row is formed by a single anlage. The phylogenetic analyses indicate that <em>Erniella</em> forms a monophyletic group with <em>Bistichella</em>, <em>Keronopsis</em>, <em>Lamtostyla</em>, <em>Orthoamphisiella</em>, <em>Parabistichella</em>, <em>Paraholosticha</em>, and <em>Uroleptoides</em>.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71479726","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}

{"title":"Novel cercozoan and heterolobosean protists from the rhizosphere and phyllosphere of two endemic cacti from the Atacama Desert","authors":"Eduardo Acosta,&nbsp;Victoria Fincke,&nbsp;Frank Nitsche,&nbsp;Hartmut Arndt","doi":"10.1016/j.ejop.2023.126034","DOIUrl":"10.1016/j.ejop.2023.126034","url":null,"abstract":"<div><p><span>Cercozoans<span><span><span> and heterolobose amoebae are found across terrestrial habitats where they feed on other unicellular microbes, including bacteria, fungi and </span>microalgae. They constitute a significant fraction of soil ecosystems and are integral members of plant </span>microbiota<span>. Here, we present the results on the isolation of protozoans<span> from the rhizosphere<span> and phyllosphere of </span></span></span></span></span><em>Browningia candelaris</em> (Meyen) in the Andean Altiplano and <em>Eulychnia taltalensis</em><span> (F. Ritter) from the Coastal Cordillera of the Atacama Desert, both endemic to this ancient desert. We identified a new heterolobose amoeba species of the genus </span><em>Allovahlkampfia</em> isolated from cactus soil, three new species of the different glissomonad genera <em>Allapsa</em>, <em>Neoheteromita</em>, <em>Neocercomonas</em> and one new thecofilosean amoeba of the genus <em>Rhogostoma</em> isolated from the phyllosphere of one studied cactus. In addition, one bacterivorous flagellate was isolated from cactus spines and identified as a member of the non-scaled imbricatean family Spongomonadidae (<em>Spongomonas</em><span>). The isolation of protists<span> from cactus spines extends the knowledge on the habitat ranges of taxa typically found on plant leaves or soils. The molecular data presented here is a prerequisite for further investigations on the ecology and diversity of protists including next-generation sequencing of microhabitats in plants and the rhizosphere, allowing for deeper taxonomic classification.</span></span></p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135714916","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}

{"title":"The odd couple of protistology: Edward Heron-Allen (1861–1943) and Arthur Earland (1866–1958)","authors":"John R. Dolan","doi":"10.1016/j.ejop.2023.126023","DOIUrl":"10.1016/j.ejop.2023.126023","url":null,"abstract":"<div><p>Edward Heron-Allen and Arthur Earland were among the last great amateur foraminifera researchers. Their partnership began in 1907 and ended in 1932. While close in age to one another, they shared little more than a fascination for forams and a lack of any university training. In most other aspects, the two men were completely different. Heron-Allen was a famous upper class polymath, expert not only on forams, but also on the Persian language, violins, palm reading, history, asparagus, and barnacles. He was also an accomplished novelist and poet, who frequented literary circles. In contrast to the flamboyant Heron-Allen, Earland was a discrete civil servant who admitted to working on forams as a relief from the monotony of his job. Hence, the two were improbable partners. However, together they produced 39 substantial works on forams. Their studies concerned assemblages from Southern Ocean to the North Sea and they are today credited with the original description of 186 species. Here the distinct lives of the two men are presented, and their contributions to protistology, as partners as well as individuals, are reviewed. The case is made for considering Earland's work as neglected relative to that of Heron-Allen, except perhaps by foram taxonomists.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41233568","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}

{"title":"Copterus tyloloricatus (Ciliophora, Suctorea), a new suctorian genus and species","authors":"Igor Dovgal ,&nbsp;Atsushi Yamaguchi ,&nbsp;Daiki Kojima ,&nbsp;Yoshinari Endo","doi":"10.1016/j.ejop.2023.126036","DOIUrl":"https://doi.org/10.1016/j.ejop.2023.126036","url":null,"abstract":"<div><p>We present the description of the new suctorian genus <em>Copterus</em> gen. n. with type species <em>Copterus tyloloricatus</em><span><span> sp. n. from the family Acinetidae, inhabiting the prosomes and urosomes of calanoid<span> copepods from the northern North Pacific Ocean. The </span></span>new taxon<span> is characterized by (i) an ellipsoidal to triangular, asymmetric, dorsoventrally flattened cell body, which lies horizontally on the lorica surface; (ii) an unflattened lorica; and (iii) the presence of three to five radially arranged bundles of tentacles positioned at the edge of the body or on actinophores.</span></span></p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138448445","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}

{"title":"Identification and characterization of an ectophosphatase activity involved in Acanthamoeba castellanii adhesion to host cells","authors":"Luiz Fernando Carvalho-Kelly,&nbsp;Anita Leocadio Freitas-Mesquita,&nbsp;Clara Ferreira Pralon,&nbsp;Eduarda de Souza-Maciel,&nbsp;José Roberto Meyer-Fernandes","doi":"10.1016/j.ejop.2023.126026","DOIUrl":"10.1016/j.ejop.2023.126026","url":null,"abstract":"<div><p><em>Acanthamoeba castellanii</em> is a free-living amoeba and an opportunistic pathogen for humans that can cause encephalitis and, more commonly, <em>Acanthamoeba</em> keratitis. During its life cycle, <em>A. castellanii</em> may present as proliferative and infective trophozoites or resistant cysts. The adhesion of trophozoites to host cells is a key first step in the pathogenesis of infection. A major virulence protein of <em>Acanthamoeba</em> is a mannose-binding protein (MBP) that mediates the adhesion of amoebae to cell surfaces. Ectophosphatases are ecto-enzymes that can dephosphorylate extracellular substrates and have already been described in several microorganisms. Regarding their physiological roles, there is consistent evidence that ectophosphatase activities play an important role in parasite-host interactions. In the present work, we identified and biochemically characterized the ectophosphatase activity of <em>A. castellanii</em>. The ectophosphatase activity is acidic, stimulated by magnesium, cobalt and nickel, and presents the following apparent kinetic parameters: <em>K</em>_m = 2.12 ± 0.54 mM <em>p</em>-NPP and <em>V</em>_max = 26.12 ± 2.53 nmol <em>p</em>-NP × h⁻¹ × 10^-6 cells. We observed that sodium orthovanadate, ammonium molybdate, sodium fluoride, and inorganic phosphate are able to inhibit ectophosphatase activity. Comparing the two stages of the <em>A. castellanii</em> lifecycle, ectophosphatase activity is significantly higher in trophozoites than in cysts. The ectophosphatase activity is stimulated by mannose residues and is significantly increased when trophozoites interact with LLC-MK2 cells. The inhibition of ectophosphatase by pretreatment with sodium orthovanadate also inhibits the adhesion of trophozoites to epithelial cells. These results allow us to conclude that the ectophosphatase activity of <em>A. castellanii</em> is somehow important for the adhesion of trophozoites to their host cells. According to our data, we believe that the activation of MBP by mannose residues triggers the stimulation of ectophosphatase activity to facilitate the adhesion process.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49689427","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}

{"title":"Life history of Apocarchesium arndti Norf &  Foissner, 2010 (Ciliophora, Peritrichia) including recognition of a novel type of zooid","authors":"Álmos Becz ,&nbsp;Júlia Katalin Török","doi":"10.1016/j.ejop.2023.126022","DOIUrl":"10.1016/j.ejop.2023.126022","url":null,"abstract":"<div><p><em>Apocarchesium rosettum</em> and <em>A. arndti</em> were originally discovered in Japan (Lake Biwa) and Germany (River Rhine), respectively. We report the first record of <em>A. arndti</em><span> in the Danube and provide a detailed description of its colony development. Our findings support the theory of moderate endemicity and reveal a new, smaller zooid type in </span><em>A. arndti</em><span><span>. This zooid remains attached to the colony, connected to the stalk myoneme but lacks an aboral ciliary wreath. Unlike microzooids, it is incapable of leaving the colony. It exhibits a less spherical shape and arises from the fourth division of the colony-founder cell. Although its specific function is unknown, it is hypothesized to support the stalk dish. Our results have significant implications for understanding the systematics of vorticellids, suggesting their ancestral nature as colonial organisms characterized by a helically contracting stalk myoneme. Furthermore, the exclusive retention of the stalk myoneme by the parental cell after binary fission may serve as a synapomorphy for the Vorticellidae. We provide a descriptive analysis of the ecological environment and </span>microhabitat of </span><em>A. arndti</em> in the Danube, revealing its preference for well-developed, detritus-rich biofilms during summer, absence in late winter and spring, emergence during peak summer, and subsequent decline until mid-winter.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41132599","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}

{"title":"After 15 years, it is time for a change","authors":"Thomas Weisse","doi":"10.1016/j.ejop.2023.126027","DOIUrl":"10.1016/j.ejop.2023.126027","url":null,"abstract":"","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S093247392300072X/pdfft?md5=cc01cf712748bfef1c56fdcb14948a97&pid=1-s2.0-S093247392300072X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89717417","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}

{"title":"Expansion of the cytochrome C oxidase subunit I database and description of four new lobose testate amoebae species (Amoebozoa; Arcellinida)","authors":"Giulia M. Ribeiro ,&nbsp;Fernando Useros ,&nbsp;Kenneth Dumack ,&nbsp;Rubén González-Miguéns ,&nbsp;Ferry Siemensma ,&nbsp;Alfredo L. Porfírio-Sousa ,&nbsp;Carmen Soler-Zamora ,&nbsp;João Pedro Barbosa Alcino ,&nbsp;Daniel J.G. Lahr ,&nbsp;Enrique Lara","doi":"10.1016/j.ejop.2023.126013","DOIUrl":"10.1016/j.ejop.2023.126013","url":null,"abstract":"<div><p>Arcellinida is ascending in importance in protistology, but description of their diversity still presents multiple challenges. Furthermore, applicable tools for surveillance of these organisms are still in developing stages. Importantly, a good database that sets a correspondence between molecular barcodes and species morphology is lacking. Cytochrome oxidase (COI) has been suggested as the most relevant marker for species discrimination in Arcellinida. However, some major groups of Arcellinida are still lacking a COI sequence. Here we expand the database of COI marker sequences for Arcellinids, using single-cell PCR, transcriptomics, and database scavenging. In the present work, we added 24 new Arcellinida COI sequences to the database, covering all unsampled infra- and suborders. Additionally, we added six new SSUrRNA sequences and described four new species using morphological, morphometrical, and molecular evidence: <em>Heleopera steppica, Centropyxis blatta, Arcella uspiensis,</em> and <em>Cylindrifflugia periurbana</em>. This new database will provide a new starting point to address new research questions from shell evolution, biogeography, and systematics of arcellinids.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10192892","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}

{"title":"Acanthamoeba castellanii trophozoites escape killing by neutrophil extracellular traps using their 3′-nucleotidase/nuclease activity","authors":"Luiz Fernando Carvalho-Kelly ,&nbsp;Anita Leocadio Freitas-Mesquita ,&nbsp;Michelle T.C. Nascimento ,&nbsp;Claudia F. Dick ,&nbsp;Eduarda de Souza-Maciel ,&nbsp;Natalia C. Rochael ,&nbsp;Elvira M. Saraiva ,&nbsp;José Roberto Meyer-Fernandes","doi":"10.1016/j.ejop.2023.126032","DOIUrl":"10.1016/j.ejop.2023.126032","url":null,"abstract":"<div><p><em>Acanthamoeba castellanii</em> is a free-living amoeba that acts as an opportunistic pathogen for humans and is the pathogenic agent of Acanthamoeba keratitis (AK). <em>A. castellanii</em> may present as proliferative and infective trophozoites or as resistant cysts during their life cycle. The immune response against AK is still poorly explored; however, it is well established that macrophages and neutrophils play essential roles in controlling corneal infection during the disease outcome. The release of NETs is one of the innate immune strategies to prevent parasite infection, especially when neutrophils interact with microorganisms that are too large to be phagocytosed, which is the case for amoeba species. The present work demonstrated that <em>A. castellanii</em> trophozoites can trigger NET formation upon <em>in vitro</em> interaction with neutrophils. Using DNase as a control, we observed increased parasite survival after coinciding with neutrophils, which may be correlated with NET degradation. Indeed, <em>A. castellanii</em> trophozoites degrade the NET DNA scaffold. Molecular analysis confirmed the occurrence of a 3′-nucleotidase/nuclease (3′-NT/NU) in the <em>A. castellanii</em> genome. We also demonstrated that trophozoites exhibit significantly higher 3′-NT/NU activity than cysts, which cannot trigger NET release. Considering that previous studies indicated the pathological role of 3′-NT-/NU in parasite infection, we suggest that this enzyme may act as the mechanism of escape of <em>A. castellanii</em> trophozoites from NETs.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72208918","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}