European journal of protistology最新文献

{"title":"PCNA's dual legacy in ciliates: Conserved replication scaffold and lineage-specific genome architect","authors":"Hongzhen Jiang ,&nbsp;Haicheng Li ,&nbsp;Chundi Wang ,&nbsp;Yuanyuan Wang ,&nbsp;Yongqiang Liu","doi":"10.1016/j.ejop.2025.126162","DOIUrl":"10.1016/j.ejop.2025.126162","url":null,"abstract":"<div><div>Proliferating cell nuclear antigen (PCNA) is a central scaffold in eukaryotic DNA replication, repair, and epigenetic regulation. While its roles are well-characterized in canonical model organisms, ciliates, unicellular eukaryotes with nuclear dimorphism and programmed genome remodeling, offer unparalleled insights into PCNA's functional adaptability. Their unique biology, including replication-coupled DNA elimination, macronuclear amplification, and replication band dynamics, positions PCNA at the intersection of genome stability and plasticity. This review systematically compares ciliate and human PCNA through phylogenetic, structural, and functional analyses. We reveal that ciliate PCNAs, despite ∼50 % sequence divergence from mammals, preserve conserved trimerization interfaces and partner-binding motifs, as validated by AlphaFold3-predicted models of the classical model organism <em>Tetrahymena thermophila</em> and the emerging systems <em>Euplotes eurystomus</em> and <em>Stylonychia lemnae</em>. Functional summaries highlight lineage-specific innovations, including epigenetic regulation, paralog specialization for nuclear differentiation, and replication band assembly. These findings have broader implications for elucidating replication-coupled chromatin dynamics, the adaptive evolution of multiprotein complexes, and the use of non-model organisms such as <em>E. eurystomus</em> and <em>S. lemnae</em> to uncover conserved principles of genome biology.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"100 ","pages":"Article 126162"},"PeriodicalIF":1.6,"publicationDate":"2025-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722158","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":"Trait-based predictors of feeding ecology patterns in shelled microorganisms","authors":"Rafael L. Macêdo ,&nbsp;Odete Rocha","doi":"10.1016/j.ejop.2025.126160","DOIUrl":"10.1016/j.ejop.2025.126160","url":null,"abstract":"<div><div>Functional traits provide key insights into ecological strategies and evolutionary diversification. In this study, we analyzed a comprehensive trait dataset to investigate morphological predictors of feeding ecology in testate amoebae from the Northern Holarctic realm, focusing on variability across 372 species. We also examined whether trait diversity mirrors taxonomic richness at the family level. Morphological traits included shell length, shell width, aperture dimensions, shape, and covering. The Principal Component Analysis (PCA) indicated that Axis 1 predominantly represented variation in shell and aperture size, while Axis 2 was associated with differences in overall shape proportions. Bacterivorous species exhibited the greatest morphological and taxonomic diversity, spanning 21 families and 48 genera, with mixotrophs and predators occupying nested subsets of their broader morphospace. The regression analyses demonstrated significant associations between species richness and variation in protective features, including aperture rim morphology and the presence of spines. Decision tree models identified the aperture width-to-length ratio as a key predictor of feeding strategy, although classification accuracy was lower for mixotrophs and predators. Future research should integrate shell morphology with phylogenetic data to enhance ecological strategy predictions in testate amoebae and explore hypotheses regarding functional diversification across a broader geographical scale and within different environments.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"100 ","pages":"Article 126160"},"PeriodicalIF":1.9,"publicationDate":"2025-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144711725","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":"Revision of the Acanthocystis turfacea species complex, description of Acanthocystis pohjolensis n. sp. and notes on the phylogeny of Acanthocystis","authors":"Savelii A. Poluzerov ,&nbsp;Sofiya V. Dmitrovskaya","doi":"10.1016/j.ejop.2025.126159","DOIUrl":"10.1016/j.ejop.2025.126159","url":null,"abstract":"<div><div><em>Acanthocystis turfacea</em> Carter, 1863 is the type species of the centrohelid genus <em>Acanthocystis</em> Carter, 1863, which is characterized by bifurcated spine scales. In this study, the organism reported under the name <em>A. turfacea</em> by Zlatogursky and Klimov (2016) is reidentified as <em>A. hymenodes</em> Nicholls, 2023, based on morphological and morphometric evidence. Additionally, a centrohelid with a small cell diameter (7.9–11.9 μm) and distinctive scales, previously attributed to <em>A. turfacea</em>, was isolated from a marine habitat and is described here as a new species, <em>Acanthocystis pohjolensis</em> n. sp. Molecular phylogenetic analysis based on 18S rRNA gene sequences places <em>A. pohjolensis</em> and <em>A. hymenodes</em> in a basal position within the genus <em>Acanthocystis</em>, suggesting that bifurcated spine scales are likely an ancestral trait of this genus. Furthermore, the taxonomic status of <em>A. turfacea</em> ssp. <em>decidens</em> Nicholls, 2023 is revised and elevated to species level as <em>A. decidens</em> Nicholls, 2023 n. stat. The <em>A. turfacea</em> species complex is revisited.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"100 ","pages":"Article 126159"},"PeriodicalIF":1.9,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703874","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":"Tales of the crown: An integrative approach to the testate amoeba Galeripora dentata (Ehrenberg, 1830) Siemensma, 2021 (Amoebozoa, Arcellinida, Arcellidae)","authors":"Nikola Bankov","doi":"10.1016/j.ejop.2025.126157","DOIUrl":"10.1016/j.ejop.2025.126157","url":null,"abstract":"<div><div>Species delimitation in unicellular organisms remains a significant challenge, primarily due to the limited number of taxonomically informative traits and their often adaptive nature. Moreover, most original descriptions of testate amoebae, dating from the late 19th to mid-20th century, relied solely on light microscopy, were often accompanied by inadequate diagnoses, and lacked illustrative drawings. To address the limitations of the historic phenetic classification, modern approaches are needed to resolve fundamental questions concerning true biodiversity and phylogenetic relationships. In this study, I employed an integrative framework that combines ecological data, morphological data (light and scanning electron microscopy), and biometric measurements to investigate the testate amoeba <em>Galeripora dentata</em> (Ehrenberg, 1830) Siemensma, 2021 from Bulgaria. I provide an improved diagnosis of the species, along with a synthesis of its global geographical distribution and ecological preferences.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"100 ","pages":"Article 126157"},"PeriodicalIF":1.9,"publicationDate":"2025-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144365751","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":"A new freshwater monothalamid (Rhizaria, Foraminifera) from the Pyrenees branching within a marine clade","authors":"Maria Holzmann ,&nbsp;Ferry Siemensma","doi":"10.1016/j.ejop.2025.126156","DOIUrl":"10.1016/j.ejop.2025.126156","url":null,"abstract":"<div><div>Monothalamous (single-chambered) foraminifera are widespread in marine benthic environments and are also a common part of freshwater and soil microbial communities. Based on molecular and morphological characteristics, seven non-marine families are currently recognized, branching either as sisters to marine clades or independently within the paraphyletic class Monothalamida. In this study, we describe a new monothalamous freshwater foraminifera sampled from a Pyrenean pond near the French town of Cauterets. We erect the novel genus <em>Poseidonella</em>, with its type species <em>Poseidonella transaquatica</em> sp. nov. The new species branches within the marine clade E, which includes the genera <em>Psammophaga</em>, <em>Vellaria</em>, <em>Niveus</em>, and <em>Nellya</em>. This represents the first evidence of a mixed clade comprising both marine and freshwater monothalamids, highlighting an ongoing transition from coastal marine environments to freshwater habitats.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126156"},"PeriodicalIF":1.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144255180","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":"Phagocytes of the forest: Are myxomycetes defensive mutualists for host plants?","authors":"Diana Wrigley de Basanta,&nbsp;Carlos Lado","doi":"10.1016/j.ejop.2025.126158","DOIUrl":"10.1016/j.ejop.2025.126158","url":null,"abstract":"<div><div>Myxomycetes are microscopic eukaryotic organisms classified within the phylum Amoebozoa. They are naked amoebae, with or without a flagellated stage in their life cycle, capable of forming a multinucleate cell (plasmodium) and producing fruiting bodies for spore dispersal. Myxomycetes are natural bacterivores and fungivores, consistently associated with plants or plant remains in terrestrial habitats. They are commonly found on decaying wood but also occur in living plants, where they may act as mutualists. Here, we propose that these microorganisms function as primary endophytic symbionts of plants, potentially protecting them from other endophytes. We comment on published studies that support this relationship and suggest that further evidence could be obtained through molecular or genomic approaches.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126158"},"PeriodicalIF":1.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241046","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":"Epiphytic and fimicolous myxomycetes on the island Hiddensee (Germany): rare species, new genotypes and unexpected ecological preferences","authors":"Anastasia Kochergina,&nbsp;Martin Schnittler","doi":"10.1016/j.ejop.2025.126153","DOIUrl":"10.1016/j.ejop.2025.126153","url":null,"abstract":"<div><div>Hiddensee, a small island in the Baltic Sea, is characterized by a rather dry, windy, and sunny climate, resembling a periodic desert. We studied epiphytic and fimicolous myxomycetes on the island using the moist chamber method for 101 substrate samples. A total of 37 myxomycete species were identified from 124 records, including 4 species newly recorded in Germany. Molecular barcoding revealed that 67 % of the obtained DNA sequences were new, differing by more than 1 % from their closest matches in the GenBank database. We obtained the first molecular data for <em>Didymium megalosporum</em> (found to be related to the aethaloid species <em>D. spongiosum</em> and <em>D. yulii</em>) and <em>C. elegans</em> var. <em>microspora</em> (new data for both the species and the variety). For <em>Trichia rapa</em>, described in 2023 based on a single barcoded collection, we found three different ribotypes, including one already known. Presumably undescribed taxa within the morphospecies <em>Comatricha nigra</em>, <em>Didymium squamulosum</em>, <em>Enerthenema papillatum</em>, and <em>Trichia contorta</em> were identified by molecular barcoding. Substrate preferences of myxomycetes, categorized into four substrate types (bark of living trees, leaf litter, twigs, and dung), showed distinct patterns of occurrence, with each substrate type associated with a characteristic assemblage of myxomycetes. The species composition on the bark of living trees showed a well-known dependence on bark pH and hardness, with differing pH optima and tolerance ranges among the studied species. <em>Echinostelium minutum</em> occurred across a broad pH spectrum (6.1–8.0; 11 records), whereas <em>Didymium leptotrichum</em> was restricted to a narrow pH range (7.9–8.1; 7 records). <em>Trichia munda</em> preferred relatively acidic substrates (6.4–7.2; 9 records), while <em>Perichaena luteola</em> (7.4–8.0, 5 records) was more commonly found in slightly alkaline conditions.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126153"},"PeriodicalIF":1.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144212358","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":"Composition of cercozoan diversity: Unravelling leaf, root, and soil specificity in crop plants","authors":"Julia Sacharow,&nbsp;Stefan Ratering,&nbsp;Santiago Quiroga,&nbsp;Rita Geissler-Plaum,&nbsp;Bellinda Schneider,&nbsp;Alessandra Österreicher Cunha-Dupont,&nbsp;Sylvia Schnell","doi":"10.1016/j.ejop.2025.126152","DOIUrl":"10.1016/j.ejop.2025.126152","url":null,"abstract":"<div><div>Protists are integral components of the plant holobiome, influencing plant growth and pathogenic pressure through their predatory activities. Wheat (<em>Triticum aestivum</em>), one of the most important crops globally, depends on favorable environmental conditions and effective pathogen management to achieve high yields. This study investigates the natural compositions of cercozoan diversity in winter wheat across various developmental stages (before sowing, at flowering, at ripening, and after harvesting) and plant compartments (leaves, roots, rhizosphere, and bulk soil) over two field seasons. The results revealed a pronounced dominance of the families Sandonidae, Allapsidae, Cercomonadidae, and Rhogostomidae across all samples. A strong enrichment of Sandonidae in leaf samples and Allapsidae in root samples was particularly notable. Importantly, no significant differences in cercozoan composition were observed across the different developmental stages of the plant. A comparative analysis between <em>Triticum aestivum</em> and <em>Hordeum vulgare</em> (barley) showed substantial similarity in cercozoan diversity across soil, leaf, and root compartments, with the only notable difference occurring in leaf samples during the ripening stage. The study concludes that cercozoan diversity in winter wheat is compartment-specific and remain stable across developmental stages. Further research is needed to explore cercozoan communities in greater taxonomic depth and to elucidate their ecological roles. Future studies should also assess whether similar patterns of compartmental variation and developmental consistency are observed in other major agricultural crops.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126152"},"PeriodicalIF":1.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144262808","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":"Unexpectedly high diversity of parabasalids in captive snakes from China","authors":"Zhouchun Li ,&nbsp;Yilei Zhang ,&nbsp;Lijie Tian ,&nbsp;Xinglong Song ,&nbsp;Xinyuan Wang ,&nbsp;Genhong Wang ,&nbsp;Haofeng An ,&nbsp;Olalekan Opeyemi Ayanniyi ,&nbsp;Qianming Xu ,&nbsp;Congshan Yang","doi":"10.1016/j.ejop.2025.126154","DOIUrl":"10.1016/j.ejop.2025.126154","url":null,"abstract":"<div><div>Snakes are frequently kept as pets and are considered important reservoirs of pathogenic protists. Parabasalids, single-celled protists that parasitize a broad variety of hosts, are transmitted via the fecal-oral route. Some species pose zoonotic risks, endangering the health of both humans and animals. This study reports on the diversity and prevalence of parabasalids in six captive, non-native snake species from China. A total of 753 fecal samples were collected from non-native snakes across 26 provinces in China, including five open farms, 16 private breeders, and five pet shops. The nuclear ITS1‐5.8S-ITS2 region was PCR amplified to investigate the infection rates of parabasalids and assess their kinships through phylogenetic analysis. The overall prevalence of parabasalids in the snake fecal samples was 13.28 % (100/753). While infection rates did not differ significantly among the snake species, significant differences were observed among the breeding environments. Snakes raised on farms had significantly higher infection rates (31.62 %, 43/136) compared to those from pet shops (13.24 %, 18/136) and private breeders (8.11 %, 39/481). In addition to <em>Monocercomonas colubrorum</em>, commonly found in reptiles, five other parabasalids were identified in snake fecal samples: <em>Tritrichomonas musculus</em>, <em>Tritrichomonas muris</em>, <em>Trichomonas gallinae</em>, <em>Simplicimonas moskowitzi</em>, and <em>Trichomitus batrachorum.</em> To our best knowledge, this is the first time these parabasalids have been detected in captive snakes from China. Our study revealed a diverse community of parabasalids in the intestines of snakes, including species typically parasitic in other animal groups such as mammals, birds, and amphibians. However, further investigations are required to determine whether these parabasalids have pathogenic effects on snakes or if they could be transmitted to other animals.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"99 ","pages":"Article 126154"},"PeriodicalIF":1.9,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241045","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":"Molecular phylogeny and taxonomy of three anaerobic ciliates including Bothrostoma aporobustum nov. spec. (Ciliophora, Metopida)","authors":"Wenbao Zhuang ,&nbsp;Xiaochen Feng ,&nbsp;Ran Li ,&nbsp;Xiaozhong Hu","doi":"10.1016/j.ejop.2025.126155","DOIUrl":"10.1016/j.ejop.2025.126155","url":null,"abstract":"<div><div>The order Metopida is a species-rich taxon within the obligate anaerobic ciliate class Armophorea. Metopids have garnered increasing interest due to their potential to shed light on mitochondrial evolution and symbiotic relationship between eukaryotes and prokaryotes. However, the majority of metopid species remain poorly or incompletely studied, largely due to limitations in earlier research methodologies. In this study, three species, <em>Bothrostoma aporobustum</em> nov. spec., <em>Brachonella mitriformis</em> and <em>Planometopus contractus</em>, were examined using a morpho-molecular approach. The new species is distinguished by a short proboscis-shaped snout, an average of 33 somatic kineties, and 21 adoral membranelles. <em>Brachonella mitriformis</em> is characterized by a broad obpyriform body with a narrow and flattened posterior end, an average of 53 somatic kineties and 77 adoral membranelles, and unevenly distributed dikinetids on the preoral dome. Phylogenetic analyses confirmed the validity and monophyly of the genera <em>Bothrostoma</em> and <em>Brachonella</em>, and robustly resolved the phylogenetic position of <em>Brachonella mitriformis</em>. Representatives of geographically distant populations of <em>Planometopus contractus</em> are morphologically highly similar and cluster together with strong support in SSU rRNA gene phylogenies.</div></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"100 ","pages":"Article 126155"},"PeriodicalIF":1.9,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144331472","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}