Pub Date : 2024-03-30DOI: 10.1016/j.ejop.2024.126080
Eric Odle , Siratee Riewluang , Kentaro Ageishi , Hiroshi Kajihara , Kevin C. Wakeman
Gregarines are the most biodiverse group of apicomplexan parasites. This group specializes on invertebrate hosts (e.g., ascidians, crustaceans, and polychaetes). Marine gregarines are of particular interest because they are considered to be the earliest evolving apicomplexan lineage, having subsequently speciated (and radiated) through virtually all existing animal groups. Still, mechanisms governing the broad (global) distribution and speciation patterns of apicomplexans are not well understood. The present study examines Pacific lecudinids, one of the most species-rich and diverse groups of marine gregarines. Here, marine polychaetes were collected from intertidal zones. Single trophozoite cells were isolated for light and electron microscopy, as well as molecular phylogenetic analyses using the partial 18S rRNA gene. The cytochrome c oxidase subunit 1 gene was used to confirm morphology-based host identification. This study introduces Undularius glycerae n. gen., n. sp. and Lecudina kitase n. sp. (Hokkaido, Japan), as well as Difficilina fasoliformis n. sp. (California, USA). Occurrences of Lecudina cf. longissima and Lecudina cf. tuzetae (California, USA) are also reported. Phylogenetic analysis revealed a close relationship between L. pellucida, L. tuzetae, and L. kitase n. sp. Additionally, clustering among North Atlantic and Pacific L. tuzetae formed a species complex, likely influenced by biogeography.
革囊虫是生物多样性最丰富的类囊体寄生虫。该类寄生虫专门以无脊椎动物(如腹足类、甲壳类和多毛类)为宿主。海洋革囊虫尤其引人关注,因为它们被认为是最早进化的类囊体,随后在几乎所有现有的动物群落中进行了分化(和辐射)。然而,人们对有褶类动物的广泛(全球)分布和物种演化模式的机制还不甚了解。本研究考察了太平洋鳞毛目动物,这是物种最丰富、种类最多样的海洋革囊动物类群之一。本研究从潮间带采集了海洋多毛类动物。分离出滋养体单细胞,进行光镜和电子显微镜观察,并利用部分 18S rRNA 基因进行分子系统学分析。细胞色素 c 氧化酶亚单位 1 基因用于确认基于形态的宿主鉴定。本研究介绍了 Undularius glycerae n. gen.longissima 和 Lecudina cf. tuzetae(美国加利福尼亚州)。此外,北大西洋和太平洋 L. tuzetae 之间的聚类形成了一个物种复合体,可能受到生物地理学的影响。
{"title":"Pacific marine gregarines (Apicomplexa) shed light on biogeographic speciation patterns and novel diversity among early apicomplexans","authors":"Eric Odle , Siratee Riewluang , Kentaro Ageishi , Hiroshi Kajihara , Kevin C. Wakeman","doi":"10.1016/j.ejop.2024.126080","DOIUrl":"10.1016/j.ejop.2024.126080","url":null,"abstract":"<div><p>Gregarines are the most biodiverse group of apicomplexan parasites. This group specializes on invertebrate hosts (e.g., ascidians, crustaceans, and polychaetes). Marine gregarines are of particular interest because they are considered to be the earliest evolving apicomplexan lineage, having subsequently speciated (and radiated) through virtually all existing animal groups. Still, mechanisms governing the broad (global) distribution and speciation patterns of apicomplexans are not well understood. The present study examines Pacific lecudinids, one of the most species-rich and diverse groups of marine gregarines. Here, marine polychaetes were collected from intertidal zones. Single trophozoite cells were isolated for light and electron microscopy, as well as molecular phylogenetic analyses using the partial 18S rRNA gene. The cytochrome <em>c</em> oxidase subunit 1 gene was used to confirm morphology-based host identification. This study introduces <em>Undularius glycerae</em> n. gen., n. sp. and <em>Lecudina kitase</em> n. sp. (Hokkaido, Japan), as well as <em>Difficilina fasoliformis</em> n. sp. (California, USA). Occurrences of <em>Lecudina</em> cf. <em>longissima</em> and <em>Lecudina</em> cf. <em>tuzetae</em> (California, USA) are also reported. Phylogenetic analysis revealed a close relationship between <em>L</em>. <em>pellucida</em>, <em>L</em>. <em>tuzetae</em>, and <em>L</em>. <em>kitase</em> n. sp. Additionally, clustering among North Atlantic and Pacific <em>L</em>. <em>tuzetae</em> formed a species complex, likely influenced by biogeography.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"94 ","pages":"Article 126080"},"PeriodicalIF":2.9,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140404776","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}
When the ciliate Spirostomum ambiguum is transected into two pieces, both fragments regenerate and proliferate. In the anterior fragments, which have lost their contractile vacuoles due to transection, new contractile vacuoles were formed at their posterior ends in a few minutes. When the cells were cut into three pieces, new contractile vacuoles were formed in the anterior and middle fragments, both at their posterior ends. Thus, the anterior-posterior axis of S. ambiguum was maintained after transection. Morphological repair, including the formation of the contractile vacuole, was also observed when only the anteriormost portion was transected to cut out a small fragment that did not contain part of the macronucleus. Scanning electron microscopy was performed to observe changes in the shape of the cleavage surface of S. ambiguum during the wound healing process. Within minutes after cutting, the cut surface was covered with a cilia-free membrane, preventing leakage of cytoplasmic contents. The surface of the cut area then rounded with time and was covered with cilia, completing the repair of the cut area in about one day.
{"title":"Morphological reconstruction during cell regeneration in the ciliate Spirostomum ambiguum","authors":"Maho Shimada , Masashi M. Hayakawa , Toshinobu Suzaki , Hideki Ishida","doi":"10.1016/j.ejop.2024.126079","DOIUrl":"10.1016/j.ejop.2024.126079","url":null,"abstract":"<div><p>When the ciliate <em>Spirostomum ambiguum</em> is transected into two pieces, both fragments regenerate and proliferate. In the anterior fragments, which have lost their contractile vacuoles due to transection, new contractile vacuoles were formed at their posterior ends in a few minutes. When the cells were cut into three pieces, new contractile vacuoles were formed in the anterior and middle fragments, both at their posterior ends. Thus, the anterior-posterior axis of <em>S. ambiguum</em> was maintained after transection. Morphological repair, including the formation of the contractile vacuole, was also observed when only the anteriormost portion was transected to cut out a small fragment that did not contain part of the macronucleus. Scanning electron microscopy was performed to observe changes in the shape of the cleavage surface of <em>S. ambiguum</em> during the wound healing process. Within minutes after cutting, the cut surface was covered with a cilia-free membrane, preventing leakage of cytoplasmic contents. The surface of the cut area then rounded with time and was covered with cilia, completing the repair of the cut area in about one day.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"94 ","pages":"Article 126079"},"PeriodicalIF":2.9,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140399204","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 : 2024-03-26DOI: 10.1016/j.ejop.2024.126078
Kiran J. More , Harpreet Kaur , Alastair G.B. Simpson , Frederick W. Spiegel , Joel B. Dacks
Osmoregulation is the homeostatic mechanism essential for the survival of organisms in hypoosmotic and hyperosmotic conditions. In freshwater or soil dwelling protists this is frequently achieved through the action of an osmoregulatory organelle, the contractile vacuole. This endomembrane organelle responds to the osmotic challenges and compensates by collecting and expelling the excess water to maintain the cellular osmolarity. As compared with other endomembrane organelles, this organelle is underappreciated and under-studied. Here we review the reported presence or absence of contractile vacuoles across eukaryotic diversity, as well as the observed variability in the structure, function, and molecular machinery of this organelle. Our findings highlight the challenges and opportunities for constructing cellular and evolutionary models for this intriguing organelle.
{"title":"Contractile vacuoles: a rapidly expanding (and occasionally diminishing?) understanding","authors":"Kiran J. More , Harpreet Kaur , Alastair G.B. Simpson , Frederick W. Spiegel , Joel B. Dacks","doi":"10.1016/j.ejop.2024.126078","DOIUrl":"10.1016/j.ejop.2024.126078","url":null,"abstract":"<div><p>Osmoregulation is the homeostatic mechanism essential for the survival of organisms in hypoosmotic and hyperosmotic conditions. In freshwater or soil dwelling protists this is frequently achieved through the action of an osmoregulatory organelle, the contractile vacuole. This endomembrane organelle responds to the osmotic challenges and compensates by collecting and expelling the excess water to maintain the cellular osmolarity. As compared with other endomembrane organelles, this organelle is underappreciated and under-studied. Here we review the reported presence or absence of contractile vacuoles across eukaryotic diversity, as well as the observed variability in the structure, function, and molecular machinery of this organelle. Our findings highlight the challenges and opportunities for constructing cellular and evolutionary models for this intriguing organelle.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"94 ","pages":"Article 126078"},"PeriodicalIF":2.9,"publicationDate":"2024-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0932473924000282/pdfft?md5=a737d325ac61ad6612c36ea14636eba7&pid=1-s2.0-S0932473924000282-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140404661","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}
In Euplotes, protein pheromones regulate cell reproduction and mating by binding cells in autocrine or heterologous fashion, respectively. Pheromone binding sites (receptors) are identified with membrane-bound pheromone isoforms determined by the same genes specifying the soluble forms, establishing a structural equivalence in each cell type between the two twin proteins. Based on this equivalence, autocrine and heterologous pheromone/receptor interactions were investigated analyzing how native molecules of pheromones Er-1 and Er-13, distinctive of mating compatible E. raikovi cell types, associate into crystals. Er-1 and Er-13 crystals are equally formed by molecules that associate cooperatively into oligomeric chains rigorously taking a mutually opposite orientation, and each burying two interfaces. A minor interface is pheromone-specific, while a major one is common in Er-1 and Er-13 crystals. A close structural inspection of this interface suggests that it may be used by Er-1 and Er-13 to associate into heterodimers, yet inapt to further associate into higher complexes. Pheromone-molecule homo-oligomerization into chains accounts for clustering and internalization of autocrine pheromone/receptor complexes in growing cells, while the heterodimer unsuitability to oligomerize may explain why heterologous pheromone/receptor complexes fail clustering and internalization. Remaining on the cell surface, they are credited with a key role in cell–cell mating adhesion.
{"title":"Homo- and hetero-oligomeric protein–protein associations explain autocrine and heterologous pheromone-cell interactions in Euplotes","authors":"Claudio Alimenti , Bill Pedrini , Pierangelo Luporini , Yaohan Jiang , Adriana Vallesi","doi":"10.1016/j.ejop.2024.126075","DOIUrl":"10.1016/j.ejop.2024.126075","url":null,"abstract":"<div><p>In <em>Euplotes</em>, protein pheromones regulate cell reproduction and mating by binding cells in autocrine or heterologous fashion, respectively. Pheromone binding sites (receptors) are identified with membrane-bound pheromone isoforms determined by the same genes specifying the soluble forms, establishing a structural equivalence in each cell type between the two twin proteins. Based on this equivalence, autocrine and heterologous pheromone/receptor interactions were investigated analyzing how native molecules of pheromones E<em>r</em>-1 and E<em>r</em>-13, distinctive of mating compatible <em>E. raikovi</em> cell types, associate into crystals. E<em>r</em>-1 and E<em>r</em>-13 crystals are equally formed by molecules that associate cooperatively into oligomeric chains rigorously taking a mutually opposite orientation, and each burying two interfaces. A minor interface is pheromone-specific, while a major one is common in E<em>r</em>-1 and E<em>r</em>-13 crystals. A close structural inspection of this interface suggests that it may be used by E<em>r</em>-1 and E<em>r</em>-13 to associate into heterodimers, yet inapt to further associate into higher complexes. Pheromone-molecule homo-oligomerization into chains accounts for clustering and internalization of autocrine pheromone/receptor complexes in growing cells, while the heterodimer unsuitability to oligomerize may explain why heterologous pheromone/receptor complexes fail clustering and internalization. Remaining on the cell surface, they are credited with a key role in cell–cell mating adhesion.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"94 ","pages":"Article 126075"},"PeriodicalIF":2.9,"publicationDate":"2024-03-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0932473924000257/pdfft?md5=82e08cb8220c05d2e4f00c51e6326a24&pid=1-s2.0-S0932473924000257-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140181978","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 : 2024-03-09DOI: 10.1016/j.ejop.2024.126065
Patrick J. Keeling , Mahara Mtawali , Morelia Trznadel , Samuel J. Livingston , Kevin C. Wakeman
Extreme functional reduction of mitochondria has taken place in parallel in many distantly related lineages of eukaryotes, leading to a number of recurring metabolic states with variously lost electron transport chain (ETC) complexes, loss of the tricarboxylic acid (TCA) cycle, and/or loss of the mitochondrial genome. The resulting mitochondria-related organelles (MROs) are generally structurally reduced and in the most extreme cases barely recognizable features of the cell with no role in energy metabolism whatsoever (e.g., mitosomes, which generally only make iron-sulfur clusters). Recently, a wide diversity of MROs were discovered to be hiding in plain sight: in gregarine apicomplexans. This diverse group of invertebrate parasites has been known and observed for centuries, but until recent applications of culture-free genomics, their mitochondria were unremarkable. The genomics, however, showed that mitochondrial function has reduced in parallel in multiple gregarine lineages to several different endpoints, including the most reduced mitosomes. Here we review this remarkable case of parallel evolution of MROs, and some of the interesting questions this work raises.
{"title":"Parallel functional reduction in the mitochondria of apicomplexan parasites","authors":"Patrick J. Keeling , Mahara Mtawali , Morelia Trznadel , Samuel J. Livingston , Kevin C. Wakeman","doi":"10.1016/j.ejop.2024.126065","DOIUrl":"10.1016/j.ejop.2024.126065","url":null,"abstract":"<div><p>Extreme functional reduction of mitochondria has taken place in parallel in many distantly related lineages of eukaryotes, leading to a number of recurring metabolic states with variously lost electron transport chain (ETC) complexes, loss of the tricarboxylic acid (TCA) cycle, and/or loss of the mitochondrial genome. The resulting mitochondria-related organelles (MROs) are generally structurally reduced and in the most extreme cases barely recognizable features of the cell with no role in energy metabolism whatsoever (e.g., mitosomes, which generally only make iron-sulfur clusters). Recently, a wide diversity of MROs were discovered to be hiding in plain sight: in gregarine apicomplexans. This diverse group of invertebrate parasites has been known and observed for centuries, but until recent applications of culture-free genomics, their mitochondria were unremarkable. The genomics, however, showed that mitochondrial function has reduced in parallel in multiple gregarine lineages to several different endpoints, including the most reduced mitosomes. Here we review this remarkable case of parallel evolution of MROs, and some of the interesting questions this work raises.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"94 ","pages":"Article 126065"},"PeriodicalIF":2.9,"publicationDate":"2024-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0932473924000154/pdfft?md5=2fa0d50d9ef35d502b12047cc59ed12b&pid=1-s2.0-S0932473924000154-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140129340","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 : 2024-02-28DOI: 10.1016/j.ejop.2024.126066
Siobhon Egan , Amanda D. Barbosa , Yaoyu Feng , Lihua Xiao , Una Ryan
The zoonotic potential of the protist parasites Cryptosporidium spp. and Giardia duodenalis in amphibians and reptiles raises public health concerns due to their growing popularity as pets. This review examines the prevalence and diversity of these parasites in wild and captive amphibians and reptiles to better understand the zoonotic risk. Research on Giardia in both groups is limited, and zoonotic forms of Cryptosporidium or Giardia have not been reported in amphibians. Host-adapted Cryptosporidium species dominate in reptiles, albeit some reptiles have been found to carry zoonotic (C. hominis and C. parvum) and rodent-associated (C. tyzzeri, C. muris and C. andersoni) species, primarily through mechanical carriage. Similarly, the limited reports of Giardia duodenalis (assemblages A, B and E) in reptiles may also be due to mechanical carriage. Thus, the available evidence indicates minimal zoonotic risk associated with these organisms in wild and captive frogs and reptiles. The exact transmission routes for these infections within reptile populations remain poorly understood, particularly regarding the importance of mechanical carriage. Although the risk appears minimal, continued research and surveillance efforts are necessary to gain a more comprehensive understanding of the transmission dynamics and ultimately improve our ability to safeguard human and animal health.
两栖动物和爬行动物中的原生寄生虫隐孢子虫属和杜氏贾第鞭毛虫可能会造成人畜共患病,这引起了人们对公共卫生问题的关注,因为人们越来越喜欢把两栖动物和爬行动物作为宠物。本综述探讨了这些寄生虫在野生和人工饲养的两栖动物和爬行动物中的流行率和多样性,以更好地了解人畜共患病风险。对这两类动物中贾第虫的研究很有限,两栖动物中的人畜共患隐孢子虫或贾第虫尚未见报道。爬行动物中主要是与宿主相适应的隐孢子虫,但也发现一些爬行动物携带人畜共患病隐孢子虫(C. hominis 和 C. parvum)和啮齿动物相关隐孢子虫(C. tyzzeri、C. muris 和 C. andersoni),主要是通过机械携带。同样,关于爬行动物中十二指肠贾第虫(A、B 和 E 组合)的有限报告也可能是由于机械携带所致。因此,现有证据表明,这些生物在野生和人工饲养的青蛙和爬行动物中的人畜共患病风险极低。这些传染病在爬行动物种群中的确切传播途径仍然鲜为人知,尤其是机械携带的重要性。尽管风险似乎很小,但仍有必要继续开展研究和监测工作,以便更全面地了解传播动态,最终提高我们保护人类和动物健康的能力。
{"title":"Minimal zoonotic risk of cryptosporidiosis and giardiasis from frogs and reptiles","authors":"Siobhon Egan , Amanda D. Barbosa , Yaoyu Feng , Lihua Xiao , Una Ryan","doi":"10.1016/j.ejop.2024.126066","DOIUrl":"https://doi.org/10.1016/j.ejop.2024.126066","url":null,"abstract":"<div><p>The zoonotic potential of the protist parasites <em>Cryptosporidium</em> spp. and <em>Giardia duodenalis</em> in amphibians and reptiles raises public health concerns due to their growing popularity as pets. This review examines the prevalence and diversity of these parasites in wild and captive amphibians and reptiles to better understand the zoonotic risk. Research on <em>Giardia</em> in both groups is limited, and zoonotic forms of <em>Cryptosporidium</em> or <em>Giardia</em> have not been reported in amphibians. Host-adapted <em>Cryptosporidium</em> species dominate in reptiles, albeit some reptiles have been found to carry zoonotic (<em>C. hominis</em> and <em>C. parvum</em>) and rodent-associated (<em>C. tyzzeri</em>, <em>C. muris</em> and <em>C. andersoni</em>) species, primarily through mechanical carriage. Similarly, the limited reports of <em>Giardia duodenalis</em> (assemblages A, B and E) in reptiles may also be due to mechanical carriage. Thus, the available evidence indicates minimal zoonotic risk associated with these organisms in wild and captive frogs and reptiles. The exact transmission routes for these infections within reptile populations remain poorly understood, particularly regarding the importance of mechanical carriage. Although the risk appears minimal, continued research and surveillance efforts are necessary to gain a more comprehensive understanding of the transmission dynamics and ultimately improve our ability to safeguard human and animal health.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"93 ","pages":"Article 126066"},"PeriodicalIF":2.9,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0932473924000166/pdfft?md5=f2d522799f5a06cf61e0671be64349cf&pid=1-s2.0-S0932473924000166-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140031379","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 : 2024-02-28DOI: 10.1016/j.ejop.2024.126067
Ji Hye Choi , Atef Omar , Jae-Ho Jung
During a survey of Korean marine ciliates, Trochilia sigmoides, the type species of the genus Trochilia, was collected and examined using in vivo observation and protargol impregnation. Moreover, scanning electron microscopy and 18S rRNA gene sequencing have been applied for the first time to study this species. Morphologically, T. sigmoides is characterized by the small body size, the oval body outline, and the spiral dorsal ridges. The Korean population of T. sigmoides shows only minute differences to other populations reported in the literature, mainly in body size and the number of dorsal ridges. Phylogenetic analyses based on 18S rRNA gene sequences show that T. sigmoides and T. petrani are placed together with two members of the family Kyaroikeidae, causing the family Dysteriidae to be non-monophyletic. The present new data increase the knowledge about the morphology and phylogeny of the genus Trochilia and would assist in understanding the phylogenetic relationship between the free-living Dysteriidae and the parasitic Kyaroikeidae.
{"title":"Redescription and molecular phylogeny of Trochilia sigmoides Dujardin, 1841 (Ciliophora, Cyrtophoria) collected from South Korea","authors":"Ji Hye Choi , Atef Omar , Jae-Ho Jung","doi":"10.1016/j.ejop.2024.126067","DOIUrl":"https://doi.org/10.1016/j.ejop.2024.126067","url":null,"abstract":"<div><p>During a survey of Korean marine ciliates, <em>Trochilia sigmoides</em>, the type species of the genus <em>Trochilia</em>, was collected and examined using in vivo observation and protargol impregnation. Moreover, scanning electron microscopy and 18S rRNA gene sequencing have been applied for the first time to study this species. Morphologically, <em>T. sigmoides</em> is characterized by the small body size, the oval body outline, and the spiral dorsal ridges. The Korean population of <em>T. sigmoides</em> shows only minute differences to other populations reported in the literature, mainly in body size and the number of dorsal ridges. Phylogenetic analyses based on 18S rRNA gene sequences show that <em>T. sigmoides</em> and <em>T. petrani</em> are placed together with two members of the family Kyaroikeidae, causing the family Dysteriidae to be non-monophyletic. The present new data increase the knowledge about the morphology and phylogeny of the genus <em>Trochilia</em> and would assist in understanding the phylogenetic relationship between the free-living Dysteriidae and the parasitic Kyaroikeidae.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"93 ","pages":"Article 126067"},"PeriodicalIF":2.9,"publicationDate":"2024-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140042490","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 : 2024-02-20DOI: 10.1016/j.ejop.2024.126064
Dmitry G. Zagumyonnyi, Denis V. Tikhonenkov
A new species of centrohelid heliozoans, Pterocystis polycristalepis sp. nov. (Pterocystidae), was examined using light and electron microscopy. The novel centrohelid is characterized by the presence of leaf-like spine-scales with a broad pedicel-like structure on the proximal part and many subparallel ribs on the lateral wing surface. The plate-scales are ovoid with medial tubular thickening and many subparallel ribs on the very extensive marginal rim. The closely related species Pterocystis striata has also been studied in detail using light and electron microscopy. Phylogenetic analysis of 18S rRNA gene sequences placed both species into a separate clade within Pterista. The closest morphologically characterized species to the new clade is Triangulopteris lacunata. The 18S rRNA sequence of Pseudoraphidiophrys veliformis was grouped within Pterista and found to be closely related to Pterocystis polycristalepis, Pterocystis striata, and Triangulopteris lacunata. Cyst-scales of various shapes, cell and cyst aggregations, syncytia, and a cell with a stalk were revealed in a clonal culture of P. veliformis. Analysis of the morphology and phylogenetic position of the studied species and other centrohelids revealed a large number of taxonomic and phylogenetic problems in Pterista.
{"title":"A new centrohelid heliozoan, Pterocystis polycristalepis sp. nov., and taxonomic and phylogenetic concerns within Pterista (Haptista: Centroplasthelida)","authors":"Dmitry G. Zagumyonnyi, Denis V. Tikhonenkov","doi":"10.1016/j.ejop.2024.126064","DOIUrl":"10.1016/j.ejop.2024.126064","url":null,"abstract":"<div><p>A new species of centrohelid heliozoans, <em>Pterocystis polycristalepis</em> sp. nov. (Pterocystidae), was examined using light and electron microscopy. The novel centrohelid is characterized by the presence of leaf-like spine-scales with a broad pedicel-like structure on the proximal part and many subparallel ribs on the lateral wing surface. The plate-scales are ovoid with medial tubular thickening and many subparallel ribs on the very extensive marginal rim. The closely related species <em>Pterocystis striata</em> has also been studied in detail using light and electron microscopy. Phylogenetic analysis of 18S rRNA gene sequences placed both species into a separate clade within Pterista. The closest morphologically characterized species to the new clade is <em>Triangulopteris lacunata</em>. The 18S rRNA sequence of <em>Pseudoraphidiophrys veliformis</em> was grouped within Pterista and found to be closely related to <em>Pterocystis polycristalepis</em>, <em>Pterocystis striata</em>, and <em>Triangulopteris lacunata.</em> Cyst-scales of various shapes, cell and cyst aggregations, syncytia, and a cell with a stalk were revealed in a clonal culture of <em>P. veliformis</em>. Analysis of the morphology and phylogenetic position of the studied species and other centrohelids revealed a large number of taxonomic and phylogenetic problems in Pterista.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"94 ","pages":"Article 126064"},"PeriodicalIF":2.9,"publicationDate":"2024-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139927991","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 : 2024-02-12DOI: 10.1016/j.ejop.2024.126063
Franciane Cedrola , Suyane Costa Bordim , Pedro Braga Arcuri , Jailton da Costa Carneiro , Roberto Júnio Pedroso Dias
Since their discovery, rumen ciliates of domestic cattle have been reported from various geographic locations. However, until now there is only one taxonomic inventory of ciliates associated with Brazilian cattle. The present study aimed to assess the community composition, relative abundance, richness, and density of rumen ciliates in Brazilian cattle, whose feeding diets were supplemented with crescent urea levels. Across all treatments analyzed, one subclass, two orders, three families, 11 genera, and 31 species of ciliates were identified. The ciliate community composition and species richness varied among the four treatments used. However, the total ciliate density was not affected by the experimental diets. We described a new entodiniid morphotype, Entodinium caudatum m. orbonuclearis, and recorded Oligoisotricha bubali for the second time in Brazil.
{"title":"Rumen ciliates (Ciliophora, Trichostomatia) in Brazilian domestic cattle feeding on diets with crescent urea levels","authors":"Franciane Cedrola , Suyane Costa Bordim , Pedro Braga Arcuri , Jailton da Costa Carneiro , Roberto Júnio Pedroso Dias","doi":"10.1016/j.ejop.2024.126063","DOIUrl":"10.1016/j.ejop.2024.126063","url":null,"abstract":"<div><p>Since their discovery, rumen ciliates of domestic cattle have been reported from various geographic locations. However, until now there is only one taxonomic inventory of ciliates associated with Brazilian cattle. The present study aimed to assess the community composition, relative abundance, richness, and density of rumen ciliates in Brazilian cattle, whose feeding diets were supplemented with crescent urea levels. Across all treatments analyzed, one subclass, two orders, three families, 11 genera, and 31 species of ciliates were identified. The ciliate community composition and species richness varied among the four treatments used. However, the total ciliate density was not affected by the experimental diets. We described a new entodiniid morphotype, <em>Entodinium caudatum</em> m. <em>orbonuclearis</em>, and recorded <em>Oligoisotricha bubali</em> for the second time in Brazil.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"93 ","pages":"Article 126063"},"PeriodicalIF":2.9,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139891548","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 : 2024-02-05DOI: 10.1016/j.ejop.2024.126062
Zhaorui Zhou , Chao Li , Qingxiang Yuan , Yong Chi , Yuqing Li , Ying Yan , Saleh A. Al-Farraj , Naomi A. Stover , Zigui Chen , Xiao Chen
Many ciliated protists prey on other large microbial organisms, including other protists and microscopic metazoans. The ciliate class Litostomatea unites both predatory and endosymbiotic species. The evolution of predation ability in ciliates remains poorly understood, in part, due to a lack of genomic data. To fill this gap, we acquired the transcriptome profiles of six predatory litostomateans using single-cell sequencing technology and investigated their transcriptomic features. Our results show that: (1) in contrast to non-predatory ciliates, the predatory litostomateans have expanded gene families associated with transmembrane activity and reactive oxidative stress response pathways, potentially as a result of cellular behaviors such as fast contraction and extension; (2) the expansion of the calcium-activated BK potassium channel gene family, which hypothetically regulates cell contractility, is an ancient evolutionary event for the class Litostomatea, suggesting a rewired metabolism associated with the hunting behavior of predatory ciliates; and (3) three whole genome duplication (WGD) events have been detected in litostomateans, with genes associated with biosynthetic processes, transmembrane activity, and calcium-activated potassium channel activity being retained during the WGD events. In addition, we explored the evolutionary relationships among 17 ciliate species, including eight litostomateans, and provided a rich foundational dataset for future in-depth phylogenomic studies of Litostomatea. Our comprehensive analyses suggest that the rewired cellular metabolism via expanded gene families and WGD events might be the potential genetic basis for the predation ability of raptorial ciliates.
{"title":"Single-cell transcriptomic analysis reveals genome evolution in predatory litostomatean ciliates","authors":"Zhaorui Zhou , Chao Li , Qingxiang Yuan , Yong Chi , Yuqing Li , Ying Yan , Saleh A. Al-Farraj , Naomi A. Stover , Zigui Chen , Xiao Chen","doi":"10.1016/j.ejop.2024.126062","DOIUrl":"https://doi.org/10.1016/j.ejop.2024.126062","url":null,"abstract":"<div><p>Many ciliated protists prey on other large microbial organisms, including other protists and microscopic metazoans. The ciliate class Litostomatea unites both predatory and endosymbiotic species. The evolution of predation ability in ciliates remains poorly understood, in part, due to a lack of genomic data. To fill this gap, we acquired the transcriptome profiles of six predatory litostomateans using single-cell sequencing technology and investigated their transcriptomic features. Our results show that: (1) in contrast to non-predatory ciliates, the predatory litostomateans have expanded gene families associated with transmembrane activity and reactive oxidative stress response pathways, potentially as a result of cellular behaviors such as fast contraction and extension; (2) the expansion of the calcium-activated BK potassium channel gene family, which hypothetically regulates cell contractility, is an ancient evolutionary event for the class Litostomatea, suggesting a rewired metabolism associated with the hunting behavior of predatory ciliates; and (3) three whole genome duplication (WGD) events have been detected in litostomateans, with genes associated with biosynthetic processes, transmembrane activity, and calcium-activated potassium channel activity being retained during the WGD events. In addition, we explored the evolutionary relationships among 17 ciliate species, including eight litostomateans, and provided a rich foundational dataset for future in-depth phylogenomic studies of Litostomatea. Our comprehensive analyses suggest that the rewired cellular metabolism via expanded gene families and WGD events might be the potential genetic basis for the predation ability of raptorial ciliates.</p></div>","PeriodicalId":12042,"journal":{"name":"European journal of protistology","volume":"93 ","pages":"Article 126062"},"PeriodicalIF":2.9,"publicationDate":"2024-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139748116","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}