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Jiang C, Gu S, Pan T, Wang X, Qin W, Wang G, Gao X, Zhang J, Chen K, Warren A, Xiong J, Miao W. Dynamics and timing of diversification events of ciliated eukaryotes from a large phylogenomic perspective. Mol Phylogenet Evol 2024; 197:108110. [PMID: 38768875 DOI: 10.1016/j.ympev.2024.108110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 05/17/2024] [Accepted: 05/17/2024] [Indexed: 05/22/2024]
Abstract
Ciliophora, an exceptionally diverse lineage of unicellular eukaryotes, exhibits a remarkable range of species richness across classes in the ciliate Tree of Life. In this study, we have acquired transcriptome and genome data from 40 representative species in seven ciliate classes. Utilizing 247 genes and 105 taxa, we devised a comprehensive phylogenomic tree for Ciliophora, encompassing over 60 % of orders and constituting the most extensive dataset of ciliate species to date. We established a robust phylogenetic framework that encompasses ambiguous taxa and the major classes within the phylum. Our findings support the monophyly of each of two subphyla (Postciliodesmatophora and Intramacronucleata), along with three subclades (Protocruzia, CONTHREEP, and SAPML) nested within Intramacronucleata, and elucidate evolutionary positions among the major classes within the phylum. Drawing on the robust ciliate Tree of Life and three constraints, we estimated the radiation of Ciliophora around 1175 Ma during the middle of the Proterozoic Eon, and most of the ciliate classes diverged from their sister lineage during the latter half of this period. Additionally, based on the time-calibrated tree and species richness pattern, we investigated net diversification rates of Ciliophora and its classes. The global net diversification rate for Ciliophora was estimated at 0.004979 species/Ma. Heterogeneity in net diversification rates was evident at the class level, with faster rates observed in Oligohymenophorea and Spirotrichea than other classes within the subclades CONTHREEP and SAPML, respectively. Notably, our analysis suggests that variations in net diversification rates, rather than clade ages, appear to contribute to the differences in species richness in Ciliophora at the class level.
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Affiliation(s)
- Chuanqi Jiang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Siyu Gu
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Tingting Pan
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Xueyan Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Weiwei Qin
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Guangying Wang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Xinxin Gao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China
| | - Jing Zhang
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Kai Chen
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
| | - Alan Warren
- Department of Life Sciences, Natural History Museum, London, UK
| | - Jie Xiong
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Wuhan, China
| | - Wei Miao
- Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China; University of Chinese Academy of Sciences, Beijing, China; Key Laboratory of Breeding Biotechnology and Sustainable Aquaculture, Chinese Academy of Sciences, Wuhan, China; Hubei Hongshan Laboratory, Wuhan, China.
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Pomahač O, Méndez-Sánchez D, Čepička I. Bit by bit toward the diversity of metopids: Description of the genus Pidimetopus n. gen. (Ciliophora: Armophorea). J Eukaryot Microbiol 2024:e13034. [PMID: 38822648 DOI: 10.1111/jeu.13034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 04/23/2024] [Accepted: 05/03/2024] [Indexed: 06/03/2024]
Abstract
While metopids (Armophorea: Metopida) represent the most species-rich group of free-living anaerobic ciliates thriving in hypoxic environments, our understanding of their true diversity remains incomplete. Most metopid species are still characterized only morphologically. Particularly, the so-called IAC clade (named in the past after some of the taxa included, Idiometopus, Atopospira, and Clevelandellida), comprising free-living members as well as the endosymbiotic ones (order Clevelandellida), is in serious need of revision. In our study, we establish a new free-living genus in the IAC clade, Pidimetopus n. gen., with descriptions of two new species, P. nanus n. sp., and P. permonicus n. sp., using up-to-date molecular and morphologic methods. The genus is characterized by small cells (up to 75 μm long), not more than 10 adoral membranelles and eight somatic kineties, and usually, four long caudal cilia that can stiffen. In addition to morphologic and molecular characterizations, we also conducted a statistical morphotype analysis of the polymorphic species P. nanus n. sp. We discuss the relevance of the earlier morphologically described species Metopus minor as a putative collective taxon for several small metopids less than 50 μm long.
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Affiliation(s)
- Ondřej Pomahač
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Daniel Méndez-Sánchez
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
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Zhou Z, Li C, Yuan Q, Chi Y, Li Y, Yan Y, Al-Farraj SA, Stover NA, Chen Z, Chen X. Single-cell transcriptomic analysis reveals genome evolution in predatory litostomatean ciliates. Eur J Protistol 2024; 93:126062. [PMID: 38368736 DOI: 10.1016/j.ejop.2024.126062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/31/2024] [Accepted: 01/31/2024] [Indexed: 02/20/2024]
Abstract
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.
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Affiliation(s)
- Zhaorui Zhou
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Chao Li
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Qingxiang Yuan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Yong Chi
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Yuqing Li
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Ying Yan
- Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Saleh A Al-Farraj
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Naomi A Stover
- Department of Biology, Bradley University, Peoria 61625, USA.
| | - Zigui Chen
- Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
| | - Xiao Chen
- Laboratory of Marine Protozoan Biodiversity and Evolution, Marine College, Shandong University, Weihai 264209, China; Suzhou Research Institute, Shandong University, Suzhou 215123, China.
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Rotterová J, Pánek T, Salomaki ED, Kotyk M, Táborský P, Kolísko M, Čepička I. Single cell transcriptomics reveals UAR codon reassignment in Palmarella salina (Metopida, Armophorea) and confirms Armophorida belongs to APM clade. Mol Phylogenet Evol 2024; 191:107991. [PMID: 38092322 DOI: 10.1016/j.ympev.2023.107991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2023] [Revised: 12/04/2023] [Accepted: 12/09/2023] [Indexed: 12/17/2023]
Abstract
Anaerobes have emerged in several major lineages of ciliates, but the number of independent transitions to anaerobiosis among ciliates is unknown. The APM clade (Armophorea, Muranotrichea, Parablepharismea) represents the largest clade of obligate anaerobes among ciliates and contains free-living marine and freshwater representatives as well as gut endobionts of animals. The evolution of APM group has only recently started getting attention, and our knowledge on its phylogeny and genetics is still limited to a fraction of taxa. While ciliates portray a wide array of alternatives to the standard genetic code across numerous classes, the APM ciliates were considered to be the largest group using exclusively standard nuclear genetic code. In this study, we present a pan-ciliate phylogenomic analysis with emphasis on the APM clade, bringing the first phylogenomic analysis of the family Tropidoatractidae (Armophorea) and confirming the position of Armophorida within Armophorea. We include five newly sequenced single cell transcriptomes from marine, freshwater, and endobiotic APM ciliates - Palmarella salina, Anteclevelandella constricta, Nyctotherus sp., Caenomorpha medusula, and Thigmothrix strigosa. We report the first discovery of an alternative nuclear genetic code among APM ciliates, used by Palmarella salina (Tropidoatractidae, Armophorea), but not by its close relative, Tropidoatractus sp., and provide a comparative analysis of stop codon identity and frequency indicating the precedency to the UAG codon loss/reassignment over the UAA codon reassignment in the specific ancestor of Palmarella. Comparative genomic and proteomic studies of this group may help explain the constraints that underlie UAR stop-to-sense reassignment, the most frequent type of alternative nuclear genetic code, not only in ciliates, but eukaryotes in general.
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Affiliation(s)
- Johana Rotterová
- Department of Zoology, Faculty of Science, Charles University, Prague 128 00, Czech Republic; Department of Marine Sciences, University of Puerto Rico Mayagüez, Mayagüez, PR, USA.
| | - Tomáš Pánek
- Department of Zoology, Faculty of Science, Charles University, Prague 128 00, Czech Republic
| | - Eric D Salomaki
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, České Budějovice 370 05, Czech Republic; Center for Computational Biology of Human Disease and Center for Computation and Visualization, Brown University, Providence, Rhode Island, USA
| | - Michael Kotyk
- Department of Zoology, Faculty of Science, Charles University, Prague 128 00, Czech Republic
| | - Petr Táborský
- Department of Zoology, Faculty of Science, Charles University, Prague 128 00, Czech Republic
| | - Martin Kolísko
- Institute of Parasitology, Biology Centre Czech Academy of Sciences, České Budějovice 370 05, Czech Republic
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague 128 00, Czech Republic.
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Zhuang W, Feng X, Li R, Al-Farraj SA, Hu X. Morphogenesis of an anaerobic ciliate Heterometopus palaeformis (Kahl, 1927) Foissner, 2016 (Ciliophora, Armophorea) with notes on its morphological and molecular characterization. Protist 2024; 175:126007. [PMID: 38141417 DOI: 10.1016/j.protis.2023.126007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 11/30/2023] [Accepted: 12/14/2023] [Indexed: 12/25/2023]
Abstract
The morphology, morphogenesis, and molecular phylogeny of Heterometopus palaeformis (Kahl, 1927) Foissner, 2016 were studied using microscopical observations on live and protargol-stained specimens as well SSU rRNA gene sequencing. The morphogenetic data for the genus are presented for the first time. Compared to other metopids, the morphogenesis of H. palaeformis is distinct since its (1) perizonal stripe rows 4 and 5 are involved in the formation of the opisthe's adoral polykinetids; (2) perizonal stripe rows 3-5 and two adjacent preoral dome kineties contribute to most of the opisthe's paroral membrane while perizonal stripe rows 1 and 2 contribute very little; (3) four kinety rows are formed to the left of the opisthe's adoral zone of polykinetids. The Chinese population resembles the original and neotype populations well in terms of general morphology - characterized by a life size of 55-120 × 10-20 μm, an elongate ellipsoidal body with a hardly spiralized flat preoral dome, about 18 somatic kineties and 20 adoral polykinetids. The SSU rDNA sequence of the present population exhibits a disparity of 1.33%-2.22% divergence from sequences of other populations. Nevertheless, phylogenetic analysis reveals that populations of H. palaeformis form a separate, stable cluster within the paraphyletic Metopidae clade.
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Affiliation(s)
- Wenbao Zhuang
- College of Fisheries, & Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Xiaochen Feng
- College of Fisheries, & Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Ran Li
- College of Fisheries, & Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Saleh A Al-Farraj
- Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
| | - Xiaozhong Hu
- College of Fisheries, & Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
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Li R, Zhuang W, Feng X, Hines HN, Hu X. First redescription and molecular phylogeny of Trimyema claviforme Kahl, 1933 with the description of a Chinese population of Plagiopyla nasuta Stein, 1860 (Ciliophora, Plagiopylea). Eur J Protistol 2023; 90:126003. [PMID: 37453202 DOI: 10.1016/j.ejop.2023.126003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 06/14/2023] [Accepted: 06/17/2023] [Indexed: 07/18/2023]
Abstract
Ciliates belonging to the class Plagiopylea are obligate anaerobes that are often neglected due to their cryptic lifestyles, difficulty of observation, and overall under-sampling. Here, we investigate two species, namely Trimyema claviforme Kahl, 1933 and Plagiopyla nasuta Stein, 1860, collected in China from marine and freshwater anaerobic sediments, respectively. A complete morphological dataset, together with SSU rRNA gene sequence data were obtained and used to diagnose the species. No molecular sequencing had ever been performed on Trimyema claviforme, with its ciliature also previously unknown. Based on these novel data presented here, the ciliate is characterized by a claviform cell shape, with a size of 35-45 × 10-20 μm in vivo, 28-39 longitudinal somatic ciliary rows forming five ciliary girdles (four complete girdles and a shorter one), two dikinetids left to anterior end of oral kinety 1, and an epaulet. A Chinese population of the well-known ciliate P. nasuta was investigated, and morphological comparisons revealed phenotypic stability of the species. The phylogenetic analyses supported previous findings about the monophyly of the families Trimyemidae and Plagiopylidae, with Trimyema claviforme branching off early in the genus Trimyema. The Chinese population of P. nasuta clusters together with two other populations with full support corroborating their conspecificity.
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Affiliation(s)
- Ran Li
- College of Fisheries, Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Wenbao Zhuang
- College of Fisheries, Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Xiaochen Feng
- College of Fisheries, Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China
| | - Hunter N Hines
- Harbor Branch Oceanographic Institute, Florida Atlantic University, Fort Pierce, Florida 34946, USA
| | - Xiaozhong Hu
- College of Fisheries, Key Laboratory of Mariculture, Ministry of Education, Ocean University of China, Qingdao 266003, China; Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
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Su H, Xu J, Li J, Yi Z. Four ciliate-specific expansion events occurred during actin gene family evolution of eukaryotes. Mol Phylogenet Evol 2023; 184:107789. [PMID: 37105243 DOI: 10.1016/j.ympev.2023.107789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/21/2023] [Accepted: 04/14/2023] [Indexed: 04/29/2023]
Abstract
Actin gene family is a divergent and ancient eukaryotic cellular cytoskeletal gene family, and participates in many essential cellular processes. Ciliated protists offer us an excellent opportunity to investigate gene family evolution, since their gene families evolved faster in ciliates than in other eukaryotes. Nonetheless, actin gene family is well studied in few model ciliate species but little is known about its evolutionary patterns in ciliates. Here, we analyzed the evolutionary pattern of eukaryotic actin gene family based on genomes/transcriptomes of 36 species covering ten ciliate classes, as well as those of nine non-ciliate eukaryotic species. Results showed: (1) Except for conventional actins and actin-related proteins (Arps) shared by various eukaryotes, at least four ciliate-specific subfamilies occurred during evolution of actin gene family. Expansions of Act2 and ArpC were supposed to have happen in the ciliate common ancestor, while expansions of ActI and ActII may have occurred in the ancestor of Armophorea, Muranotrichea, and Spirotrichea. (2) The number of actin isoforms varied greatly among ciliate species. Environmental adaptability, whole genome duplication (WGD) or segmental duplication events, distinct spatial and temporal patterns of expression might play driving forces for the increasement of isoform numbers. (3) The 'birth and death' model of evolution could explain the evolution of actin gene family in ciliates. And actin genes have been generally under strong negative selection to maintain protein structures and physiological functions. Collectively, we provided meaningful information for understanding the evolution of eukaryotic actin gene family.
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Affiliation(s)
- Hua Su
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Jiahui Xu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Jia Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China
| | - Zhenzhen Yi
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, School of Life Science, South China Normal University, Guangzhou 510631, China.
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