IF 2.1 3区生物学

Protist Pub Date : 2025-08-06 DOI: 10.1016/j.protis.2025.126116

Valentin Kokarev, Suzanne C. Dufour

{"title":"The first record of a gregarine from the family Urosporidae (Apicomplexa: Lecudinoidea) in a bivalve mollusc, Axinopsida orbiculata","authors":"Valentin Kokarev, Suzanne C. Dufour","doi":"10.1016/j.protis.2025.126116","DOIUrl":"10.1016/j.protis.2025.126116","url":null,"abstract":"<div><div>Urosporid gregarines are an understudied group of coelomic and intestinal extracellular parasites of marine invertebrates. To date, they have been recorded in various hosts, including annelids, nemerteans, echinoderms and gastropods. In the present paper, we describe a new urosporid gregarine, <em>Gonospora axinopsidae</em> sp. nov., the first in this family known to infect a bivalve mollusc, <em>Axinopsida orbiculata</em>. Trophozoites and oocysts within gametocysts were observed within the bivalve's mantle cavity and hemocoel. The morphology and ultrastructure of these life stages are described using scanning and transmission electron microscopy. The 18S rRNA sequence of <em>Gonospora axinopsidae</em> sp. nov. suggests strong phylogenetic affinity with the genus <em>Difficilina,</em> which infects the intestine of nemerteans. This report increases the known host range of urosporid gregarines. The described morphological and genetic characteristics of <em>Gonospora axinopsidae</em> sp. nov. can support further studies aiming to elucidate phylogenetic relationships within marine gregarines.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"178 ","pages":"Article 126116"},"PeriodicalIF":2.1,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144878568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Characterizing lineage-specific genes in testate lobose amoebae (Arcellinida) 雄性叶状变形虫（Arcellinida）谱系特异性基因的研究

IF 2.1 3区生物学

Protist Pub Date : 2025-08-05 DOI: 10.1016/j.protis.2025.126115

Angela K. Jiang , Taylor R. Sehein , Rebecca Gawron , Laura A. Katz , Xyrus X. Maurer-Alcalá

{"title":"Characterizing lineage-specific genes in testate lobose amoebae (Arcellinida)","authors":"Angela K. Jiang , Taylor R. Sehein , Rebecca Gawron , Laura A. Katz , Xyrus X. Maurer-Alcalá","doi":"10.1016/j.protis.2025.126115","DOIUrl":"10.1016/j.protis.2025.126115","url":null,"abstract":"<div><div>Arcellinida are an abundant and diverse order of testate (shelled) amoebae that are important bioindicators of changing climates. Despite their ecological importance, the molecular mechanisms that underlie their adaptations, including those involving lineage-specific genes, remain largely unknown. Lineage-specific gene families (LSGFs) are linked to evolutionary innovations, yet the evolution of LSGFs remains underexplored across the tree of life, with most research restricted to model eukaryotes. Here, we assess the evolution of Arcellinida-specific gene families using a set of 197 Arcellinida transcriptomes representing 12 Arcellinida genera. We employ a conservative filtering approach to identify 3424 Arcellinda-specific gene families. Our analyses show that these lineage-specific gene families are shorter and exhibit lower expression compared to more conserved genes, congruent with trends observed in other eukaryotic lineages. Although there are inherent limitations regarding missing data with transcriptomics, we recover substantially more lineage-specific gene family births in the symbiont-bearing species <em>Hyalosphenia papilio</em> compared to <em>Hyalosphenia elegans</em>. Our results demonstrate a method to identify lineage-specific genes in non-model organisms where no reference genome are available, and expand our understanding of the evolution of lineage-specific genes in eukaryotes.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"178 ","pages":"Article 126115"},"PeriodicalIF":2.1,"publicationDate":"2025-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Soil ciliates' response to glyphosate exposure: A microcosm experiment 土壤纤毛虫对草甘膦暴露的反应：一个微观实验

IF 1.9 3区生物学

Protist Pub Date : 2025-07-02 DOI: 10.1016/j.protis.2025.126112

Hai T.T. Luu , Genoveva F. Esteban , Iain D. Green

{"title":"Soil ciliates' response to glyphosate exposure: A microcosm experiment","authors":"Hai T.T. Luu , Genoveva F. Esteban , Iain D. Green","doi":"10.1016/j.protis.2025.126112","DOIUrl":"10.1016/j.protis.2025.126112","url":null,"abstract":"<div><div>The widespread use of glyphosate, a broad-spectrum herbicide, in agriculture raises concerns about its impact on non-target organisms and ecosystem functions. Research on glyphosate's effect on soil microorganisms has been inconsistent due to varying methodologies and focuses. To address this, a controlled microcosm study was conducted to investigate glyphosate's impact on soil ciliates, an essential component of soil microbial communities. This study is among the first to examine glyphosate impact on ciliates. The experiment used agricultural soil with glyphosate applied at standard and elevated rates. Ciliate abundance and species richness were monitored in the microcosms at 1-, 7-, and 15-days post-application. Soil ciliates showed remarkable tolerance to glyphosate at standard application rates, with a notable increase in abundance after 15 days, primarily driven by one species' proliferation. This study demonstrates the resilience of ciliate communities to standard glyphosate rates, suggesting their crucial role in maintaining soil functionality in the presence of the herbicide. However, it also highlights potential ecological risks at higher glyphosate concentrations, as evidenced by the loss of ciliate species at the highest rates tested. These findings contribute to our understanding of glyphosate's impact on soil ecosystems and highlights the importance of further research in this area.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"178 ","pages":"Article 126112"},"PeriodicalIF":1.9,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144589144","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The apparently misunderstood Didinium Gargantua of Alphonse Meunier 显然被误解的阿尔方斯·穆尼耶的巨型Didinium

IF 1.9 3区生物学

Protist Pub Date : 2025-06-24 DOI: 10.1016/j.protis.2025.126111

John R. Dolan

{"title":"The apparently misunderstood Didinium Gargantua of Alphonse Meunier","authors":"John R. Dolan","doi":"10.1016/j.protis.2025.126111","DOIUrl":"10.1016/j.protis.2025.126111","url":null,"abstract":"<div><div><span><span>Meunier's, 1910</span></span> “<em>Microplankton des Mers de Barents et de Kara</em>” was the first monographic treatment of protists of the arctic plankton, and it contained many descriptions of new species of a variety of taxa. Among the most conspicuous was the ciliate <em>Didinium Garantua</em>, named with a capital G, corresponding with the title character, the gluttonous giant, of Rabelais' 1534 novel, <em>Gargantua</em>, a classic of French literature. Meunier described <em>D. gargantua</em> at length in the text as a large voracious predator, and devoted many figures to it. As of today, it has been reported from a surprising diversity of marine and estuarine ecosystems, for example, from Antarctic sea-ice, to the Gulf of Mexico, the Chesapeake Bay, and the Caspian Sea. However, most reports concern specimens of sizes considerably smaller than most of those depicted by Meunier, and cite no taxonomic authorities for ciliate identifications, suggesting that many researchers may be unfamiliar <span><span>Meunier's, 1910</span></span> monograph, thus with the ‘gargantuan' nature of his <em>D. gargantua</em>. Here, a brief biography of Meunier is given first, followed by a description of his 1910 monograph, and then a summary of his text, and some of his remarkable figures of <em>D. gargantua</em> are presented. Finally, subsequent reports of the occurrence of <em>D. gargantua</em> are reviewed, and it is suggested that many concern a species distinct from <em>D. gargantua</em>, as there are large differences in size and shapes compared to Meunier's species.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"178 ","pages":"Article 126111"},"PeriodicalIF":1.9,"publicationDate":"2025-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphology and ultrastructure of marine bacterivorous bicosoecid Hirugamonas aperieos gen. et sp. nov. 海洋嗜菌生物鱿鱼的形态和超微结构。

IF 1.9 3区生物学

Protist Pub Date : 2025-06-02 DOI: 10.1016/j.protis.2025.126104

Tatsuya Kishikami, Marina Ota, Kasumi Ishida, Kazumasa Yamada, Takafumi Kataoka

{"title":"Morphology and ultrastructure of marine bacterivorous bicosoecid Hirugamonas aperieos gen. et sp. nov.","authors":"Tatsuya Kishikami, Marina Ota, Kasumi Ishida, Kazumasa Yamada, Takafumi Kataoka","doi":"10.1016/j.protis.2025.126104","DOIUrl":"10.1016/j.protis.2025.126104","url":null,"abstract":"<div><div>Heterotrophic nanoflagellates (HNF) are recognized as active bacterivores in marine environments. We report the isolation and culture of a strain of HNF obtained from the seawater of Lake Hiruga. The organism has two flagella of different length, a long anterior flagellum with tripartite mastigonemes and a short smooth posterior flagellum; a spiral fiber was observed in the transition zone of the flagella. The spherical or D-shaped cell has a groove with one stretchable edge and is supported by 6–8 microtubule bundle that extends from the basal bodies and forms a cytostome. Additionally, the isolate lacked lorica, body scales, cytopharynx, or acronematic structure of flagella, and thus it could not be assigned to any known genera in the order Bicosoecida. Phylogenetic analysis of 18S rRNA gene sequences from Bicosoecida confirmed an independent clade at the genus level with the closest relative genus being <em>Bicosoeca</em>. The optimal salinity and temperature ranges for growth was 21 %–30 % and 25–31 °C, respectively, indicating a marine mesophilic HNF. Thus, based on the morphological features and phylogenetic analysis of 18S rRNA gene sequences, we propose a novel genus for the isolate: <em>Hirugamonas</em>, n. gen. The species name <em>Hirugamonas aperieos</em> sp. nov. is proposed.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"178 ","pages":"Article 126104"},"PeriodicalIF":1.9,"publicationDate":"2025-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144280907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Piercing the veil: A novel amoebozoan (Janelia veilia n. gen. n. sp.) reveals deep clades within Discosea through phylogenomics 揭开面纱：一种新的变形虫（Janelia veilia n. gen. n. sp.）通过系统基因组学揭示了Discosea内部的深层分支

IF 1.9 3区生物学

Protist Pub Date : 2025-05-03 DOI: 10.1016/j.protis.2025.126103

Robert E. Jones , Quentin Blandenier , Felicity Kleitz-Singleton , Tristan C. Henderson , Nicholas W. Fry , Idan Banson , Jonah Nguyen , Alexander K. Tice , Matthew W. Brown

{"title":"Piercing the veil: A novel amoebozoan (Janelia veilia n. gen. n. sp.) reveals deep clades within Discosea through phylogenomics","authors":"Robert E. Jones , Quentin Blandenier , Felicity Kleitz-Singleton , Tristan C. Henderson , Nicholas W. Fry , Idan Banson , Jonah Nguyen , Alexander K. Tice , Matthew W. Brown","doi":"10.1016/j.protis.2025.126103","DOIUrl":"10.1016/j.protis.2025.126103","url":null,"abstract":"<div><div>Three major groups of primarily amoeboid taxa are present across Amoebozoa: Discosea, Evosea, and Tubulinea. While each of these groups were thought to have morphologically unique traits and members, the morphologic boundaries between each group have recently blurred. For example, it is demonstrated that several taxa in each group display monopodial limax amoebae, a characteristic most often associated with Tubulinea. Here we describe a novel discosean amoeba isolated from a freshwater pond, <em>Janelia veilia</em> n. gen. n. sp. Its cells have variable morphologies, but often display monopodial limax amoebae, with a unique trailing structure that appears to be derived from cellular material. In some cases, cells have conical pseudopodia or pointed pseudopodia. Using phylogenomics, we find that this taxon branches as sister to the recently described discosean <em>Mycamoeba gemmipara</em> and the sporocarpic protosteloid amoeba <em>Microglomus paxillus</em>, forming an order-level group we term Mycamoebida. Mycamoebida is fully supported as sister to Dermamoebida, together forming a subclass we term Dermelia. SSU rRNA phylogenies show that <em>Janelia veilia</em> n. gen. n. sp. is molecularly unique from any known organism, but branches with high support in a clade containing <em>Mycamoeba gemmipara</em> and several environmental sequences suggesting a larger diverse clade within Discosea.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"177 ","pages":"Article 126103"},"PeriodicalIF":1.9,"publicationDate":"2025-05-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143906538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Transcriptomic analyses reveal sexual cues in reproductive life stages of uncultivated Acantharia (Radiolaria) 转录组学分析揭示了未栽培棘虫（Radiolaria）生殖阶段的性暗示

IF 1.9 3区生物学

Protist Pub Date : 2025-04-28 DOI: 10.1016/j.protis.2025.126102

Iris Rizos , Sarah Romac , Caroline Juery , Charlotte Berthelier , Johan Decelle , Juliana Bernardes , Erwan Corre , Lucie Bittner , Fabrice Not

{"title":"Transcriptomic analyses reveal sexual cues in reproductive life stages of uncultivated Acantharia (Radiolaria)","authors":"Iris Rizos , Sarah Romac , Caroline Juery , Charlotte Berthelier , Johan Decelle , Juliana Bernardes , Erwan Corre , Lucie Bittner , Fabrice Not","doi":"10.1016/j.protis.2025.126102","DOIUrl":"10.1016/j.protis.2025.126102","url":null,"abstract":"<div><div>The ability to reproduce is a key process for the perpetuation of organisms. Along the evolution of protist reproductive strategies, the molecular machinery of sexual recombination is estimated to have been inherited from the last eukaryotic common ancestor (LECA). Unraveling the sexual cycles of free-living protists remains challenging, given the enigmatic roles of many uncultivated life stages. For the planktonic group of Acantharia (Radiolaria), a hypothetical sexual cycle has been proposed since the late 19th century, including a gamete-like stage, referred to as swarmers. In order to investigate the sexual nature of acantharian reproductive stages, we compared transcriptomes of various acantharian life stages. Our results show distinct functional profiles for reproductive and vegetative stages, while revealing the expression of the gamete fusion genes, HAP2/GCS1 and KAR5-GEX1-BMB in swarmers. Annotation of differentially expressed life stage-specific genes, also highlighted putative meiosis-related functions among pre-swarmer and swarmer stages, while suggesting the existence of a putative zygotic stage. This original life stage-specific genetic data is coherent with morphological evidence supporting the acantharian sexual cycle, with swarmers acting as gametes. Moreover, it paves the way for a deeper understanding of radiolarian cell biology and ecology at a single-cell scale.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"177 ","pages":"Article 126102"},"PeriodicalIF":1.9,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143928096","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Unveiling the remarkable diversity of the genus Hypotrichomonas (Parabasalia: Hypotrichomonadidae) in cockroaches (Blattodea, excluding Isoptera) 揭示蟑螂（小蠊总目，不包括等翅目）中滴虫属（副滴虫目：滴虫科）的显著多样性

IF 1.9 3区生物学

Protist Pub Date : 2025-04-15 DOI: 10.1016/j.protis.2025.126100

Michael Kotyk , Zuzana Kotyková Varadínová , Pavla Hrubá , Ivan Čepička

{"title":"Unveiling the remarkable diversity of the genus Hypotrichomonas (Parabasalia: Hypotrichomonadidae) in cockroaches (Blattodea, excluding Isoptera)","authors":"Michael Kotyk , Zuzana Kotyková Varadínová , Pavla Hrubá , Ivan Čepička","doi":"10.1016/j.protis.2025.126100","DOIUrl":"10.1016/j.protis.2025.126100","url":null,"abstract":"<div><div>Parabasalid hindgut symbionts of the xylophagous Isoptera/<em>Cryptocercus</em> lineage (Blattodea: Blattoidea) have been attracting the interest of biologists for decades. However, the parabasalids from other cockroaches (Blattodea excluding Isoptera) remain largely unstudied. The genus <em>Hypotrichomonas</em>, along with genus <em>Trichomitus</em>, belongs to the small parabasalid order Hypotrichomonadida. So far, ten valid <em>Hypotrichomonas</em> species have been described from animals, both vertebrates and invertebrates. Here we have uncovered an extensive diversity of this genus in cockroaches. We have obtained 72 isolates from 41 cockroach species and one from a water-filled tree hole. Using a combination of light-microscopic morphology of protargol-stained cells, scanning electron microscopy, and a phylogenetic analysis of SSU rRNA gene, we show that our strains represent multiple novel <em>Hypotrichomonas</em> species, and we formally describe seven of them. Our data show that the evolutionary center of the genus likely lies in cockroaches. Moreover, the new evolutionary lineages of <em>Hypotrichomonas</em> from cockroaches show a high degree of host specificity.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"177 ","pages":"Article 126100"},"PeriodicalIF":1.9,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A novel free-living endomyxan flagellate Viscidocauda repens gen. Nov., sp. nov 一种新的自由生活的内生鞭毛软尾纲动物，repens gen. Nov., sp. Nov.

IF 1.9 3区生物学

Protist Pub Date : 2025-04-14 DOI: 10.1016/j.protis.2025.126101

Takashi Shiratori, Ken-ichiro Ishida

引用次数: 0

Morphology and phylogeny of Prorocentrum venetum Tolomio & Cavolo (Dinophyceae) 龙足科原中央兽类的形态与系统发育

IF 1.9 3区生物学

Protist Pub Date : 2025-04-03 DOI: 10.1016/j.protis.2025.126099

Daniel Grzebyk , Mona Hoppenrath , Urban Tillmann

{"title":"Morphology and phylogeny of Prorocentrum venetum Tolomio & Cavolo (Dinophyceae)","authors":"Daniel Grzebyk , Mona Hoppenrath , Urban Tillmann","doi":"10.1016/j.protis.2025.126099","DOIUrl":"10.1016/j.protis.2025.126099","url":null,"abstract":"<div><div><em>Prorocentrum venetum</em> was one of the first species of the genus <em>Prorocentrum</em> described by scanning electron microscopy by Tolomio and Cavolo in 1985. Since the first observation of the species in the Venice Lagoon (Italy) in summer 1981, it has not been reported again in published phytoplankton records of Mediterranean waters or elsewhere. Two strains were isolated from a French Mediterranean lagoon, which were morphologically identified as <em>P. venetum</em> by microscopy. Based on rDNA sequences (spanning the 18S to the D3 region of 28S rDNA), the phylogenetic analysis demonstrated that <em>P. venetum</em> belongs to the same clade as <em>Prorocentrum triestinum</em> and <em>Prorocentrum redfieldii</em>. The analysis of scanning electron micrographs provided an in-depth morphological description of the theca, particularly on the pore pattern of thecal plates and new structural details of the platelets in the periflagellar area. These morphological characteristics were compared with the closely related species within the <em>P. triestinum</em> clade, which showed synapomorphic characters in the periflagellar area (small accessory pore, platelet pattern, shape of the apical wing). Further comparison of characteristics varying between species in this clade and in the sister clade encompassing species related to <em>Prorocentrum micans</em> suggests some features of morphological evolution within this part of the genus.</div></div>","PeriodicalId":20781,"journal":{"name":"Protist","volume":"177 ","pages":"Article 126099"},"PeriodicalIF":1.9,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

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