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Ribeiro GM, Useros F, Dumack K, González-Miguéns R, Siemensma F, Porfírio-Sousa AL, Soler-Zamora C, Pedro Barbosa Alcino J, Lahr DJG, Lara E. Expansion of the cytochrome C oxidase subunit I database and description of four new lobose testate amoebae species (Amoebozoa; Arcellinida). Eur J Protistol 2023; 91:126013. [PMID: 37690315 DOI: 10.1016/j.ejop.2023.126013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 09/12/2023]
Abstract
Arcellinida is ascending in importance in protistology, but description of their diversity still presents multiple challenges. Furthermore, applicable tools for surveillance of these organisms are still in developing stages. Importantly, a good database that sets a correspondence between molecular barcodes and species morphology is lacking. Cytochrome oxidase (COI) has been suggested as the most relevant marker for species discrimination in Arcellinida. However, some major groups of Arcellinida are still lacking a COI sequence. Here we expand the database of COI marker sequences for Arcellinids, using single-cell PCR, transcriptomics, and database scavenging. In the present work, we added 24 new Arcellinida COI sequences to the database, covering all unsampled infra- and suborders. Additionally, we added six new SSUrRNA sequences and described four new species using morphological, morphometrical, and molecular evidence: Heleopera steppica, Centropyxis blatta, Arcella uspiensis, and Cylindrifflugia periurbana. This new database will provide a new starting point to address new research questions from shell evolution, biogeography, and systematics of arcellinids.
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Affiliation(s)
- Giulia M Ribeiro
- Department of Zoology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
| | | | - Kenneth Dumack
- Department of Terrestrial Ecology, Institute of Zoology, University of Cologne, Germany
| | | | | | | | | | | | - Daniel J G Lahr
- Department of Zoology, Biosciences Institute, University of São Paulo, São Paulo, Brazil
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2
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González-Miguéns R, Cano E, Guillén-Oterino A, Quesada A, Lahr DJG, Tenorio-Rodríguez D, de Salvador-Velasco D, Velázquez D, Carrasco-Braganza MI, Patterson RT, Lara E, Singer D. A needle in a haystack: A new metabarcoding approach to survey diversity at the species level of Arcellinida (Amoebozoa: Tubulinea). Mol Ecol Resour 2023. [PMID: 36799013 DOI: 10.1111/1755-0998.13771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 02/02/2023] [Accepted: 02/14/2023] [Indexed: 02/18/2023]
Abstract
Environmental DNA-based diversity studies have increased in popularity with the development of high throughput sequencing technologies. This permits the potential simultaneous retrieval of vast amounts of molecular data from many different organisms and species, thus contributing to a wide range of biological disciplines. Environmental DNA protocols designed for protists often focused on the highly conserved small subunit of the ribosome gene, that does not permit species-level assignments. On the other hand, eDNA protocols aiming at species-level assignments allow a fine level ecological resolution and reproducible results. These protocols are currently applied to organisms living in marine and shallow lotic freshwater ecosystems, often in a bioindication purpose. Therefore, in this study, we present a species-level eDNA protocol designed to explore diversity of Arcellinida (Amoebozoa: Tubulinea) testate amoebae taxa that is based on mitochondrial cytochrome oxidase subunit I (COI). These organisms are widespread in lentic water bodies and soil ecosystems. We applied this protocol to 42 samples from peatlands, estuaries and soil environments, recovering all the infraorders in Glutinoconcha (with COI data), except for Hyalospheniformes. Our results revealed an unsuspected diversity in morphologically homogeneous groups such as Cylindrothecina, Excentrostoma or Sphaerothecina. With this protocol we expect to revolutionize the design of modern distributional Arcellinida surveys. Our approach involves a rapid and cost-effective analysis of testate amoeba diversity living in contrasted ecosystems. Therefore, the order Arcellinida has the potential to be established as a model group for a wide range of theoretical and applied studies.
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Affiliation(s)
| | - Emilio Cano
- Department of Mycology, Real Jardín Botánico (RJB-CSIC), Madrid, Spain.,Research Support Unit, Real Jardín Botánico (CSIC), Madrid, Spain
| | - Antonio Guillén-Oterino
- Estación Biológica Internacional Duero-Douro (EUROPARQUES-EBI), Buque hidrográfico Helios-Cousteau en el Lago de Sanabria, Castilla y León, Spain
| | - Antonio Quesada
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Daniel Tenorio-Rodríguez
- Estación Biológica Internacional Duero-Douro (EUROPARQUES-EBI), Buque hidrográfico Helios-Cousteau en el Lago de Sanabria, Castilla y León, Spain
| | - David de Salvador-Velasco
- Estación Biológica Internacional Duero-Douro (EUROPARQUES-EBI), Buque hidrográfico Helios-Cousteau en el Lago de Sanabria, Castilla y León, Spain
| | - David Velázquez
- Department of Biology, Universidad Autónoma de Madrid, Madrid, Spain
| | - María Isabel Carrasco-Braganza
- Estación Biológica Internacional Duero-Douro (EUROPARQUES-EBI), Buque hidrográfico Helios-Cousteau en el Lago de Sanabria, Castilla y León, Spain
| | - R Timothy Patterson
- Ottawa-Carleton Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
| | - Enrique Lara
- Department of Mycology, Real Jardín Botánico (RJB-CSIC), Madrid, Spain
| | - David Singer
- Ottawa-Carleton Geoscience Centre and Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada.,UMR CNRS 6112 LPG-BIAF, Laboratory of Planetology and Geosciences, Angers University and Nantes Université, Angers, France
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3
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González-Miguéns R, Todorov M, Blandenier Q, Duckert C, Porfirio-Sousa AL, Ribeiro GM, Ramos D, Lahr DJG, Buckley D, Lara E. Deconstructing Difflugia: The tangled evolution of lobose testate amoebae shells (Amoebozoa: Arcellinida) illustrates the importance of convergent evolution in protist phylogeny. Mol Phylogenet Evol 2022; 175:107557. [PMID: 35777650 DOI: 10.1016/j.ympev.2022.107557] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/25/2022] [Accepted: 05/31/2022] [Indexed: 10/17/2022]
Abstract
Protists, the micro-eukaryotes that are neither plants, animals nor fungi build up the greatest part of eukaryotic diversity on Earth. Yet, their evolutionary histories and patterns are still mostly ignored, and their complexity overlooked. Protists are often assumed to keep stable morphologies for long periods of time (morphological stasis). In this work, we test this paradigm taking Arcellinida testate amoebae as a model. We build a taxon-rich phylogeny based on two mitochondrial (COI and NADH) and one nuclear (SSU) gene, and reconstruct morphological evolution among clades. In addition, we prove the existence of mitochondrial mRNA editing for the COI gene. The trees show a lack of conservatism of shell outlines within the main clades, as well as a widespread occurrence of morphological convergences between far-related taxa. Our results refute, therefore, a widespread morphological stasis, which may be an artefact resulting from low taxon coverage. As a corollary, we also revise the groups systematics, notably by emending the large and highly polyphyletic genus Difflugia. These results lead, amongst others, to the erection of a new infraorder Cylindrothecina, as well as two new genera Cylindrifflugia and Golemanskia.
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Affiliation(s)
| | - Milcho Todorov
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Science, 1113 Sofia, Bulgaria
| | - Quentin Blandenier
- Laboratory of Soil Biodiversity, University of Neuchâtel, Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Clément Duckert
- Laboratory of Soil Biodiversity, University of Neuchâtel, Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | | | - Giulia M Ribeiro
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil
| | - Diana Ramos
- Real Jardín Botánico (RJB-CSIC), Plaza Murillo 2, 28014 Madrid, Spain
| | - Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil
| | - David Buckley
- Department of Biology (Genetics), Universidad Autónoma de Madrid, Spain; Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Universidad Autónoma de Madrid, Spain
| | - Enrique Lara
- Real Jardín Botánico (RJB-CSIC), Plaza Murillo 2, 28014 Madrid, Spain.
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4
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Wang W, Gao X, Ndayishimiye JC, Lara E, Lahr DJG, Qian H, Ren K, Chen H, Yang J. Population and molecular responses to warming in Netzelia tuberspinifera - An endemic and sensitive protist from East Asia. Sci Total Environ 2022; 806:150897. [PMID: 34653464 DOI: 10.1016/j.scitotenv.2021.150897] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/05/2021] [Accepted: 10/05/2021] [Indexed: 06/13/2023]
Abstract
With the effects of global warming becoming ever more obvious, biodiversity conservation is facing severe challenges. Currently, a deeper understanding the mechanisms of the effects of warming on sensitive species has become an important topic in aquatic biodiversity and ecological management. Our study first overcame the "challenge" for a sensitive indicator species (Netzelia tuberspinifera, an endemic testate amoeba species in East Asia) of culturing under laboratory conditions, and then explored its molecular response mechanisms to warming using transcriptomic analysis. Our data indicate that temperature mainly drove the geographical and seasonal variation of N. tuberspinifera populations. Transcriptomic results indicate that when the temperature is <25 °C, rising temperature triggers the biosynthesis of ribosomes; while the temperature is >25 °C, it triggers molecular processes related with cell division, test formation and general biomass increase. However, once the temperature exceeds 40 °C, N. tuberspinifera is unable to survive. Following from these results, the distribution of N. tuberspinifera might expand towards higher altitude or latitude regions under global warming. For the first time, our study showed direct evidence for sensitive protozoa species that presents a very narrow adaptation mechanism to local climate. Our work provides fundamental data for regional biodiversity conservation and scientific reference in subtropical and tropical waterbodies.
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Affiliation(s)
- Wenping Wang
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaofei Gao
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; College of Fisheries, Henan Normal University, Xinxiang 453007, China
| | - Jean Claude Ndayishimiye
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Enrique Lara
- Real Jardın Botanico, CSIC, Plaza de Murillo 2, Madrid 28014, Spain
| | - Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil
| | - Haifeng Qian
- College of Environment, Zhejiang University of Technology, Hangzhou 310032, China
| | - Kexin Ren
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Huihuang Chen
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jun Yang
- Aquatic EcoHealth Group, Fujian Key Laboratory of Watershed Ecology, Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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5
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Trevisan B, Jacob Machado D, Lahr DJG, Marques FPL. Comparative Characterization of Mitogenomes From Five Orders of Cestodes (Eucestoda: Tapeworms). Front Genet 2022; 12:788871. [PMID: 35003223 PMCID: PMC8727539 DOI: 10.3389/fgene.2021.788871] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Accepted: 11/23/2021] [Indexed: 12/26/2022] Open
Abstract
The recognized potential of using mitogenomics in phylogenetics and the more accessible use of high-throughput sequencing (HTS) offer an opportunity to investigate groups of neglected organisms. Here, we leveraged HTS to execute the most comprehensive documentation of mitogenomes for cestodes based on the number of terminals sequenced. We adopted modern approaches to obtain the complete mitogenome sequences of 86 specimens representing five orders of cestodes (three reported for the first time: Phyllobothriidea, “Tetraphyllidea” and Trypanorhyncha). These complete mitogenomes represent an increase of 41% of the mitogenomes available for cestodes (61–147) and an addition of 33% in the representativeness of the cestode orders. The complete mitochondrial genomes are conserved, circular, encoded in the same strand, and transcribed in the same direction, following the pattern observed previously for tapeworms. Their length varies from 13,369 to 13,795 bp, containing 36 genes in total. Except for the Trypanorhyncha specimen, the gene order of the other four cestode orders sequenced here suggests that it could be a synapomorphy for the acetabulate group (with a reversion for taenids). Our results also suggest that no single gene can tell all the evolutionary history contained in the mitogenome. Therefore, cestodes phylogenies based on a single mitochondrial marker may fail to capture their evolutionary history. We predict that such phylogenies would be improved if conducted under a total evidence framework. The characterization of the new mitochondrial genomes is the first step to provide a valuable resource for future studies on the evolutionary relationships of these groups of parasites.
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Affiliation(s)
- Bruna Trevisan
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Denis Jacob Machado
- Department of Bioinformatics and Genomics, College of Computing and Informatics, University of North Carolina at Charlotte, Charlotte, NC, United States
| | - Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | - Fernando P L Marques
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
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6
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Abstract
Rab GTPase is a paralog-rich gene family that controls the maintenance of the eukaryotic cell compartmentalization system. Diverse eukaryotes have varying numbers of Rab paralogs. Currently, little is known about the evolutionary pattern of Rab GTPase in most major eukaryotic 'supergroups'. Here, we present a comprehensive phylogenetic reconstruction of the Rab GTPase gene family in the eukaryotic 'supergroup' Amoebozoa, a diverse lineage represented by unicellular and multicellular organisms. We demonstrate that Amoebozoa conserved 20 of the 23 ancestral Rab GTPases predicted to be present in the last eukaryotic common ancestor and massively expanded several 'novel' in-paralogs. Due to these 'novel' in-paralogs, the Rab family composition dramatically varies between the members of Amoebozoa; as a consequence, 'supergroup'-based studies may significantly change our current understanding of the evolution and diversity of this gene family. The high diversity of the Rab GTPase gene family in Amoebozoa makes this 'supergroup' a key lineage to study and advance our knowledge of the evolution of Rab in Eukaryotes.
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Affiliation(s)
| | - Alexander K. Tice
- Department of Biological Sciences, Mississippi State University, Starkville, Mississippi, USA,Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, Mississippi, USA
| | - Matthew W. Brown
- Department of Biological Sciences, Mississippi State University, Starkville, Mississippi, USA,Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, Mississippi, USA,Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Daniel J. G. Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil,CONTACT Daniel J. G. Lahr Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, Brazil
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7
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Kang S, Tice AK, Stairs CW, Jones RE, Lahr DJG, Brown MW. The integrin-mediated adhesive complex in the ancestor of animals, fungi, and amoebae. Curr Biol 2021; 31:3073-3085.e3. [PMID: 34077702 DOI: 10.1016/j.cub.2021.04.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 03/17/2021] [Accepted: 04/28/2021] [Indexed: 11/25/2022]
Abstract
Integrins are transmembrane receptors that activate signal transduction pathways upon extracellular matrix binding. The integrin-mediated adhesive complex (IMAC) mediates various cell physiological processes. Although the IMAC was thought to be specific to animals, in the past ten years these complexes were discovered in other lineages of Obazoa, the group containing animals, fungi, and several microbial eukaryotes. Very recently, many genomes and transcriptomes from Amoebozoa (the eukaryotic supergroup sister to Obazoa), other obazoans, orphan protist lineages, and the eukaryotes' closest prokaryotic relatives, have become available. To increase the resolution of where and when IMAC proteins exist and have emerged, we surveyed these newly available genomes and transcriptomes for the presence of IMAC proteins. Our results highlight that many of these proteins appear to have evolved earlier in eukaryote evolution than previously thought and that co-option of this apparently ancient protein complex was key to the emergence of animal-type multicellularity. The role of the IMACs in amoebozoans is unknown, but they play critical adhesive roles in at least some unicellular organisms.
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Affiliation(s)
- Seungho Kang
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Courtney W Stairs
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden; Department of Biology, Lund University, Lund, Sweden
| | - Robert E Jones
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Daniel J G Lahr
- Department of Zoology, University of São Paulo, São Paulo, Brazil
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Starkville, MS, USA.
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8
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Marcisz K, Jassey VEJ, Kosakyan A, Krashevska V, Lahr DJG, Lara E, Lamentowicz Ł, Lamentowicz M, Macumber A, Mazei Y, Mitchell EAD, Nasser NA, Patterson RT, Roe HM, Singer D, Tsyganov AN, Fournier B. Testate Amoeba Functional Traits and Their Use in Paleoecology. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2020.575966] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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9
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Hofstatter PG, Ribeiro GM, Porfírio‐Sousa AL, Lahr DJG. The Sexual Ancestor of all Eukaryotes: A Defense of the “Meiosis Toolkit”. Bioessays 2020; 42:e2000037. [DOI: 10.1002/bies.202000037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/08/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Paulo G. Hofstatter
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Giulia M. Ribeiro
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Alfredo L. Porfírio‐Sousa
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
| | - Daniel J. G. Lahr
- Universidade de São Paulo Instituto de Biociencias, Rua do Matão, travessa 14, A101. São Paulo, CEP.: 05508‐090, Brazil
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10
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Ribeiro GM, Porfírio-Sousa AL, Maurer-Alcalá XX, Katz LA, Lahr DJG. De novo Sequencing, Assembly, and Annotation of the Transcriptome for the Free-Living Testate Amoeba Arcella intermedia. J Eukaryot Microbiol 2020; 67:383-392. [PMID: 31971327 DOI: 10.1111/jeu.12788] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/19/2019] [Accepted: 12/22/2019] [Indexed: 11/29/2022]
Abstract
Arcella, a diverse understudied genus of testate amoebae is a member of Tubulinea in Amoebozoa group. Transcriptomes are a powerful tool for characterization of these organisms as they are an efficient way of characterizing the protein-coding potential of the genome. In this work, we employed both single-cell and clonal populations transcriptomics to create a reference transcriptome for Arcella. We compared our results with annotations of Dictyostelium discoideum, a model Amoebozoan. We assembled a pool of 38 Arcella intermedia transcriptomes, which after filtering are composed of a total of 14,712 translated proteins. There are GO categories enriched in Arcella including mainly intracellular signal transduction pathways; we also used KEGG to annotate 11,546 contigs, which also have similar distribution to Dictyostelium. A large portion of data is still impossible to assign to a gene family, probably due to a combination of lineage-specific genes, incomplete sequences in the transcriptome and rapidly evolved genes. Some absences in pathways could also be related to low expression of these genes. We provide a reference database for Arcella, and we highlight the emergence of the need for further gene discovery in Arcella.
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Affiliation(s)
- Giulia M Ribeiro
- Department of Zoology, Institute of Biosciences, University of São Paulo, Matao Street, Travessa 14 Cidade Universitaria, São Paulo, 05508-090, São Paulo, Brazil
| | - Alfredo L Porfírio-Sousa
- Department of Zoology, Institute of Biosciences, University of São Paulo, Matao Street, Travessa 14 Cidade Universitaria, São Paulo, 05508-090, São Paulo, Brazil
| | - Xyrus X Maurer-Alcalá
- Department of Biological Sciences, Smith College, 10 Elm Street, Northampton, Massachusetts, 01063.,Program in Organismic and Evolutionary Biology, University of Massachussetts Amherst, 230 Stockbridge Road, Amherst, Massachusetts, 01002-9316
| | - Laura A Katz
- Department of Biological Sciences, Smith College, 10 Elm Street, Northampton, Massachusetts, 01063
| | - Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, Matao Street, Travessa 14 Cidade Universitaria, São Paulo, 05508-090, São Paulo, Brazil
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11
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Hofstatter PG, Lahr DJG. All Eukaryotes Are Sexual, unless Proven Otherwise: Many So-Called Asexuals Present Meiotic Machinery and Might Be Able to Have Sex. Bioessays 2019; 41:e1800246. [PMID: 31087693 DOI: 10.1002/bies.201800246] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 03/15/2019] [Indexed: 11/07/2022]
Abstract
Here a wide distribution of meiotic machinery is shown, indicating the occurrence of sexual processes in all major eukaryotic groups, without exceptions, including the putative "asexuals." Meiotic machinery has evolved from archaeal DNA repair machinery by means of ancestral gene duplications. Sex is very conserved and widespread in eukaryotes, even though its evolutionary importance is still a matter of debate. The main processes in sex are plasmogamy, followed by karyogamy and meiosis. Meiosis is fundamentally a chromosomal process, which implies recombination and ploidy reduction. Several eukaryotic lineages are proposed to be asexual because their sexual processes are never observed, but presumed asexuality correlates with lack of study. The authors stress the complete lack of meiotic proteins in nucleomorphs and their almost complete loss in the fungus Malassezia. Inversely, complete sets of meiotic proteins are present in fungal groups Glomeromycotina, Trichophyton, and Cryptococcus. Endosymbiont Perkinsela and endoparasitic Microsporidia also present meiotic proteins.
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Affiliation(s)
- Paulo G Hofstatter
- Departamento de ZoologiaRua do Matão, Instituto de Biociências, Universidade de São Paulo, travessa 14, 101CEP., 05508-090, Sâo Paulo, Brazil
| | - Daniel J G Lahr
- Departamento de ZoologiaRua do Matão, Instituto de Biociências, Universidade de São Paulo, travessa 14, 101CEP., 05508-090, Sâo Paulo, Brazil
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12
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Lahr DJG, Kosakyan A, Lara E, Mitchell EAD, Morais L, Porfirio-Sousa AL, Ribeiro GM, Tice AK, Pánek T, Kang S, Brown MW. Phylogenomics and Morphological Reconstruction of Arcellinida Testate Amoebae Highlight Diversity of Microbial Eukaryotes in the Neoproterozoic. Curr Biol 2019; 29:991-1001.e3. [PMID: 30827918 DOI: 10.1016/j.cub.2019.01.078] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 10/26/2018] [Accepted: 01/30/2019] [Indexed: 11/26/2022]
Abstract
Life was microbial for the majority of Earth's history, but as very few microbial lineages leave a fossil record, the Precambrian evolution of life remains shrouded in mystery. Shelled (testate) amoebae stand out as an exception with rich documented diversity in the Neoproterozoic as vase-shaped microfossils (VSMs). While there is general consensus that most of these can be attributed to the Arcellinida lineage in Amoebozoa, it is still unclear whether they can be used as key fossils for interpretation of early eukaryotic evolution. Here, we present a well-resolved phylogenomic reconstruction based on 250 genes, obtained using single-cell transcriptomic techniques from a representative selection of 19 Arcellinid testate amoeba taxa. The robust phylogenetic framework enables deeper interpretations of evolution in this lineage and demanded an updated classification of the group. Additionally, we performed reconstruction of ancestral morphologies, yielding hypothetical ancestors remarkably similar to existing Neoproterozoic VSMs. We demonstrate that major lineages of testate amoebae were already diversified before the Sturtian glaciation (720 mya), supporting the hypothesis that massive eukaryotic diversification took place in the early Neoproterozoic and congruent with the interpretation that VSM are arcellinid testate amoebae.
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Affiliation(s)
- Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil.
| | - Anush Kosakyan
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil; Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Branišovská 1160/31, 37005, České Budějovice, Czech Republic
| | - Enrique Lara
- Real Jardín Botánico, CSIC, Plaza Murillo 2, ES 28014 Madrid, Spain; Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Edward A D Mitchell
- Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland; Botanical Garden of Neuchâtel, Pertuis-du-Sault 58, 2000 Neuchâtel, Switzerland
| | - Luana Morais
- Department of Geophysics, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, Brazil
| | | | - Giulia M Ribeiro
- Department of Zoology, Institute of Biosciences, University of São Paulo, Brazil
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Tomáš Pánek
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Department of Biology and Ecology, Faculty of Science, University of Ostrava, Czech Republic
| | - Seungho Kang
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, USA
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Starkville, MS, USA; Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Starkville, MS, USA.
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13
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Ribeiro GM, Prado PI, Coutinho RM, Rillo MC, Pereira Junior S, Porfirio-Sousa AL, Lahr DJG. Growth Rate Modulation Enables Coexistence in a Competitive Exclusion Scenario Between Microbial Eukaryotes. ACTA PROTOZOOL 2019. [DOI: 10.4467/16890027ap.19.019.12021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Coexistence usually are exceeding the explicable rate by competitive exclusion principle. Since the pioneer Gause, many studies have used protist microcosm systems to study competitive exclusion. We explored a two-species system with the testate-amoebae: (Arcella intermedia and Pyxidicula operculata), where competitive exclusion is expected to occur. We determined their growth curves individually and under competitive interaction. We used a state-space model to represent system dynamics and calculated posterior population sizes simulating competition dynamics. Contrarily to our expectation, Arcella and Pyxidicula showed similar growth rates (1.37 and 1.46 days–1 respectively) and only different carrying capacity (1,997 and 25,108 cells cm–2 respectively). The maximum number of cells of both species when growing in competition was much lower if compared to the monospecific cultures (in average, 73% and 80% less for Arcella and Pyxidicula respectively). However, our competition experiments always resulted in coexistence. According to the models, the drop in growth rates and stochasticity mainly explains our coexistence results. We propose that a context of ephemeral resources can explain these results. Additionally, we propose generating factors of stochasticity as intraspecific variation, small population effects, toxicity of waste products and influence of the bacterial community.
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14
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Abstract
Sex and reproduction are often treated as a single phenomenon in animals and plants, as in these organisms reproduction implies mixis and meiosis. In contrast, sex and reproduction are independent biological phenomena that may or may not be linked in the majority of other eukaryotes. Current evidence supports a eukaryotic ancestor bearing a mating type system and meiosis, which is a process exclusive to eukaryotes. Even though sex is ancestral, the literature regarding life cycles of amoeboid lineages depicts them as asexual organisms. Why would loss of sex be common in amoebae, if it is rarely lost, if ever, in plants and animals, as well as in fungi? One way to approach the question of meiosis in the "asexuals" is to evaluate the patterns of occurrence of genes for the proteins involved in syngamy and meiosis. We have applied a comparative genomic approach to study the occurrence of the machinery for plasmogamy, karyogamy, and meiosis in Amoebozoa, a major amoeboid supergroup. Our results support a putative occurrence of syngamy and meiotic processes in all major amoebozoan lineages. We conclude that most amoebozoans may perform mixis, recombination, and ploidy reduction through canonical meiotic processes. The present evidence indicates the possibility of sexual cycles in many lineages traditionally held as asexual.
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Affiliation(s)
- Paulo G Hofstatter
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University
| | - Daniel J G Lahr
- Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, Brazil
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15
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Dumack K, Kahlich C, Lahr DJG, Bonkowski M. Reinvestigation of Phryganella paradoxa
(Arcellinida, Amoebozoa) Penard 1902. J Eukaryot Microbiol 2018; 66:232-243. [DOI: 10.1111/jeu.12665] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 05/27/2018] [Accepted: 06/19/2018] [Indexed: 02/03/2023]
Affiliation(s)
- Kenneth Dumack
- Terrestrial Ecology; Institute of Zoology; University of Cologne; Zülpicher Str. 47b 50674 Köln Germany
- Department of Zoology; Institute of Biosciences; University of São Paulo; Rua do Matão, tv. 14, 101 05508-090 São Paulo Brazil
| | - Christopher Kahlich
- Terrestrial Ecology; Institute of Zoology; University of Cologne; Zülpicher Str. 47b 50674 Köln Germany
| | - Daniel J. G. Lahr
- Department of Zoology; Institute of Biosciences; University of São Paulo; Rua do Matão, tv. 14, 101 05508-090 São Paulo Brazil
| | - Michael Bonkowski
- Terrestrial Ecology; Institute of Zoology; University of Cologne; Zülpicher Str. 47b 50674 Köln Germany
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16
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Kang S, Tice AK, Spiegel FW, Silberman JD, Pánek T, Cepicka I, Kostka M, Kosakyan A, Alcântara DMC, Roger AJ, Shadwick LL, Smirnov A, Kudryavtsev A, Lahr DJG, Brown MW. Between a Pod and a Hard Test: The Deep Evolution of Amoebae. Mol Biol Evol 2017; 34:2258-2270. [PMID: 28505375 PMCID: PMC5850466 DOI: 10.1093/molbev/msx162] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Amoebozoa is the eukaryotic supergroup sister to Obazoa, the lineage that contains the animals and Fungi, as well as their protistan relatives, and the breviate and apusomonad flagellates. Amoebozoa is extraordinarily diverse, encompassing important model organisms and significant pathogens. Although amoebozoans are integral to global nutrient cycles and present in nearly all environments, they remain vastly understudied. We present a robust phylogeny of Amoebozoa based on broad representative set of taxa in a phylogenomic framework (325 genes). By sampling 61 taxa using culture-based and single-cell transcriptomics, our analyses show two major clades of Amoebozoa, Discosea, and Tevosa. This phylogeny refutes previous studies in major respects. Our results support the hypothesis that the last common ancestor of Amoebozoa was sexual and flagellated, it also may have had the ability to disperse propagules from a sporocarp-type fruiting body. Overall, the main macroevolutionary patterns in Amoebozoa appear to result from the parallel losses of homologous characters of a multiphase life cycle that included flagella, sex, and sporocarps rather than independent acquisition of convergent features.
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Affiliation(s)
- Seungho Kang
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS.,Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, MS
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS.,Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, MS
| | | | | | - Tomáš Pánek
- Department of Biology and Ecology, University of Ostrava, Ostrava, Czech Republic
| | - Ivan Cepicka
- Department of Zoology, Charles University, Prague, Czech Republic
| | - Martin Kostka
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Českě Budějovice, Czech Republic.,Department of Parasitology, University of South Bohemia, Českě Budějovice, Czech Republic
| | - Anush Kosakyan
- Department of Zoology, University of São Paulo, São Paulo, Brazil
| | | | - Andrew J Roger
- Centre for Comparative Genomics and Evolutionary Bioinformatics, Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada
| | - Lora L Shadwick
- Department of Biological Sciences, University of Arkansas, Fayetteville, AR
| | - Alexey Smirnov
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Alexander Kudryavtsev
- Department of Invertebrate Zoology, Faculty of Biology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Daniel J G Lahr
- Department of Zoology, University of São Paulo, São Paulo, Brazil
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS.,Institute for Genomics, Biocomputing & Biotechnology, Mississippi State University, Mississippi State, MS
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17
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Moore KR, Bosak T, Macdonald FA, Lahr DJG, Newman S, Settens C, Pruss SB. Biologically agglutinated eukaryotic microfossil from Cryogenian cap carbonates. Geobiology 2017; 15:499-515. [PMID: 28063184 DOI: 10.1111/gbi.12225] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
Cryogenian cap carbonates that overlie Sturtian glacial deposits were formed during a post-glacial transgression. Here, we describe microfossils from the Kakontwe Formation of Zambia and the Taishir Formation of Mongolia-both Cryogenian age, post-Sturtian cap carbonates-and investigate processes involved in their formation and preservation. We compare microfossils from these two localities to an assemblage of well-documented microfossils previously described in the post-Sturtian Rasthof Formation of Namibia. Microfossils from both new localities have 10 ± 1 μm-thick walls composed of carbonaceous matter and aluminosilicate minerals. Those found in the Kakontwe Formation are spherical or ovoid and 90 ± 5 μm to 200 ± 5 μm wide. Structures found in the Taishir Formation are mostly spherical, 50 ± 5 μm to 140 ± 5 μm wide, with distinct features such as blunt or concave edges. Chemical and mineralogical analyses show that the walled structures and the clay fraction extracted from the surrounding sediments are composed of clay minerals, especially muscovite and illite, as well as quartz, iron and titanium oxides, and some dolomite and feldspar. At each locality, the mineralogy of the microfossil walls matched that of the clay fractions of the surrounding sediment. The abundance of these minerals in the walled microfossils relative to the surrounding carbonate matrix and microbial laminae, and the presence of minerals that cannot precipitate from solution (titanium oxide and feldspar), suggests that the composition represents the original mineralogy of the structures. Furthermore, the consistency in mineralogy of both microfossils and sediments across the three basins, and the uniformity of size and shape among mineral grains in the fossil walls indicate that these organisms incorporated these minerals by primary biological agglutination. The discovery of new, mineral-rich microfossil assemblages in microbially laminated and other fine-grained facies of Cryogenian cap carbonates from multiple localities on different palaeocontinents demonstrates that agglutinating eukaryotes were widespread in carbonate-dominated marine environments in the aftermath of the Sturtian glaciation.
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Affiliation(s)
- K R Moore
- The Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - T Bosak
- The Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - F A Macdonald
- The Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA
| | - D J G Lahr
- Department of Zoology, University of São Paulo, São Paulo SP, Brazil
| | - S Newman
- The Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - C Settens
- Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - S B Pruss
- Department of Geosciences, Smith College, Northampton, MA, USA
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18
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Gomaa F, Lahr DJG, Todorov M, Li J, Lara E. A contribution to the phylogeny of agglutinating Arcellinida (Amoebozoa) based on SSU rRNA gene sequences. Eur J Protistol 2017; 59:99-107. [PMID: 28433921 DOI: 10.1016/j.ejop.2017.03.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 03/17/2017] [Accepted: 03/22/2017] [Indexed: 10/19/2022]
Abstract
Arcellinid testate amoebae include a wide variety of amoeboid organisms whose test (shell) varies in shape, composition and size. A decade ago, we initiated molecular phylogenetic analyses based on SSU rRNA gene sequences and a taxonomic revision of Arcellinida. However, many lineages within Arcellinida still lack molecular data, and the phylogeny of this group is largely incomplete. In this study, we obtained SSU rRNA gene sequences from seven taxa, of which six have agglutinated shell (Difflugia oblonga, D. labiosa, D. gramen, Mediolus corona, Netzelia wailesi, and N. tuberculata), and one has an entirely proteinaceous shell (Arcella intermedia). All species but Difflugia oblonga branched within the recently erected suborder Sphaerothecina, confirming the synapomorphic value of an oviform or discoid shell. Thus, we propose that species with an oviform or discoid shell currently classified within genus Difflugia must be transferred to other genera, thus continuing the process of taxonomic revision of genus Difflugia, the largest Arcellinida genus. We therefore transferred the current and the previously sequenced oviform Difflugia spp. to Netzelia spp., based on the shared globular/oviform shell shape and their monophyly. Another species, D. labiosa, formed an independent lineage that branched as a sister clade to Arcella spp.; based on the shell morphology and their phylogenetic position, we considered D. labiosa as incertae sedis.
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Affiliation(s)
- Fatma Gomaa
- Department of Organismic and Evolutionary Biology, Biological Laboratory, Harvard University, Cambridge, Massachusetts, USA; Ain Shams University, Faculty of Science, Zoology Department, Cairo, Egypt.
| | - Daniel J G Lahr
- Department of Zoology, University of Sao Paulo, Sao Paulo, Brazil
| | - Milcho Todorov
- Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, 2 Gagarin St., 1113 Sofia, Bulgaria
| | - Jingchun Li
- Department of Organismic and Evolutionary Biology, Biological Laboratory, Harvard University, Cambridge, Massachusetts, USA
| | - Enrique Lara
- Laboratory of Soil Biodiversity, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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19
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Lahr DJG, Lara E, Hofstatter PG, Ribeiro GM, Porfírio-Sousa AL, Junior SP. Meeting Report: 8th International Symposium on Testate Amoebae, Ilhabela, São Paulo, Brazil, 12-14 September 2016. J Eukaryot Microbiol 2016; 64:555-557. [DOI: 10.1111/jeu.12380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 10/31/2016] [Accepted: 10/31/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Daniel J. G. Lahr
- Department of Zoology; Institute of Biosciences; University of São Paulo; São Paulo Brazil
| | - Enrique Lara
- Laboratory of Soil Biodiversity; University of Neuchâtel; Neuchâtel Switzerland
| | - Paulo G. Hofstatter
- Department of Zoology; Institute of Biosciences; University of São Paulo; São Paulo Brazil
| | - Giulia M. Ribeiro
- Department of Zoology; Institute of Biosciences; University of São Paulo; São Paulo Brazil
| | | | - Samuel P. Junior
- Department of Zoology; Institute of Biosciences; University of São Paulo; São Paulo Brazil
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20
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Hofstatter PG, Tice AK, Kang S, Brown MW, Lahr DJG. Evolution of bacterial recombinase A (recA) in eukaryotes explained by addition of genomic data of key microbial lineages. Proc Biol Sci 2016; 283:20161453. [PMID: 27708147 PMCID: PMC5069510 DOI: 10.1098/rspb.2016.1453] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/12/2016] [Indexed: 11/12/2022] Open
Abstract
Recombinase enzymes promote DNA repair by homologous recombination. The genes that encode them are ancestral to life, occurring in all known dominions: viruses, Eubacteria, Archaea and Eukaryota. Bacterial recombinases are also present in viruses and eukaryotic groups (supergroups), presumably via ancestral events of lateral gene transfer. The eukaryotic recA genes have two distinct origins (mitochondrial and plastidial), whose acquisition by eukaryotes was possible via primary (bacteria-eukaryote) and/or secondary (eukaryote-eukaryote) endosymbiotic gene transfers (EGTs). Here we present a comprehensive phylogenetic analysis of the recA genealogy, with substantially increased taxonomic sampling in the bacteria, viruses, eukaryotes and a special focus on the key eukaryotic supergroup Amoebozoa, earlier represented only by Dictyostelium We demonstrate that several major eukaryotic lineages have lost the bacterial recombinases (including Opisthokonta and Excavata), whereas others have retained them (Amoebozoa, Archaeplastida and the SAR-supergroups). When absent, the bacterial recA homologues may have been lost entirely (secondary loss of canonical mitochondria) or replaced by other eukaryotic recombinases. RecA proteins have a transit peptide for organellar import, where they act. The reconstruction of the RecA phylogeny with its EGT events presented here retells the intertwined evolutionary history of eukaryotes and bacteria, while further illuminating the events of endosymbiosis in eukaryotes by expanding the collection of widespread genes that provide insight to this deep history.
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Affiliation(s)
- Paulo G Hofstatter
- Department of Zoology, Universidade de São Paulo/USP, Cidade Universitária, São Paulo, Brazil
| | - Alexander K Tice
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Seungho Kang
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Matthew W Brown
- Department of Biological Sciences, Mississippi State University, Mississippi State, MS 39762, USA Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Daniel J G Lahr
- Department of Zoology, Universidade de São Paulo/USP, Cidade Universitária, São Paulo, Brazil
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21
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Kosakyan A, Lahr DJG, Mulot M, Meisterfeld R, Mitchell EAD, Lara E. Phylogenetic reconstruction based on
COI
reshuffles the taxonomy of hyalosphenid shelled (testate) amoebae and reveals the convoluted evolution of shell plate shapes. Cladistics 2016; 32:606-623. [DOI: 10.1111/cla.12167] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2016] [Indexed: 11/28/2022] Open
Affiliation(s)
- Anush Kosakyan
- Laboratory of Evolutionary Protistology Institute of Biosciences University of Sao Paulo Matão Travessa 14 Cidade Universitária Sao Paulo 05508‐090 SP Brazil
| | - Daniel J. G. Lahr
- Laboratory of Evolutionary Protistology Institute of Biosciences University of Sao Paulo Matão Travessa 14 Cidade Universitária Sao Paulo 05508‐090 SP Brazil
| | - Matthieu Mulot
- Laboratory of Soil Biodiversity University of Neuchatel Rue Emile‐Argand 11 Neuchatel 2000 Switzerland
| | - Ralf Meisterfeld
- Institute for Biology II (Zoology) RWTH Aachen University Worringerweg 3 Aachen 52056 Germany
| | - Edward A. D. Mitchell
- Laboratory of Soil Biodiversity University of Neuchatel Rue Emile‐Argand 11 Neuchatel 2000 Switzerland
- Jardin Botanique de Neuchâtel Chemin du Perthuis‐du‐Sault 58 Neuchâtel 2000 Switzerland
| | - Enrique Lara
- Laboratory of Soil Biodiversity University of Neuchatel Rue Emile‐Argand 11 Neuchatel 2000 Switzerland
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22
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Kosakyan A, Gomaa F, Lara E, Lahr DJG. Current and future perspectives on the systematics, taxonomy and nomenclature of testate amoebae. Eur J Protistol 2016; 55:105-117. [PMID: 27004416 DOI: 10.1016/j.ejop.2016.02.001] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 12/09/2015] [Accepted: 02/08/2016] [Indexed: 10/22/2022]
Abstract
Testate amoebae are a polyphyletic assemblage of at least three major, unrelated taxonomic groups of unicellular amoeboid eukaryotes exhibiting a test. The focus on testate amoebae in scientific research has greatly increased in the past 20 years: from an average of about 5 papers a year in the mid-1990s to the current rate of more than 50 papers published yearly. The application range of these organisms is rapidly expanding as well: from the traditional fields of environmental monitoring and paleoecology, to forensic sciences and ecotoxicology studies. These developments are nevertheless strongly dependent on reliable taxonomy and nomenclature. However, scientometric data reveal that despite an ever-increasing necessity for the use of names (the product of taxonomy), the corresponding effort has not been achieved for improving testate amoebae systematics. As a consequence, inaccurate taxonomy yields to misinterpretations in the diversity of the organisms and to potentially incorrect conclusions. These and related problems are discussed in this study, highlighting the outcome of poor taxonomic expertise in accurate classification and phylogeny of testate amoebae, and the consequences derived from it. Additionally, this study is aimed to discuss the current status of testate amoebae classification, and to present all nomenclature and taxonomic changes in higher and lower taxonomic levels of testate amoebae, as a result of recent molecular reconstructions. Finally, we conclude with a list of the needs and suggestions toward a unified and modernized taxonomy of testate amoebae.
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Affiliation(s)
- Anush Kosakyan
- Institute of Biosciences, Department of Zoology, University of Sao Paulo, Rua do Matão, Travessa 14, Cidade Universitária, 05508-090 Sao Paulo, SP, Brazil
| | - Fatma Gomaa
- Department of Organismic and Evolutionary Biology, Biological Laboratory, Harvard University, Cambridge, MA, USA; Zoology Department, Faculty of Science, Ain Shams University, Cairo, Egypt
| | - Enrique Lara
- Laboratory of Soil Biology, University of Neuchâtel, Rue Emile-Argand 11, CH-2000, Switzerland
| | - Daniel J G Lahr
- Institute of Biosciences, Department of Zoology, University of Sao Paulo, Rua do Matão, Travessa 14, Cidade Universitária, 05508-090 Sao Paulo, SP, Brazil.
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23
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Oliverio AM, Lahr DJG, Grant J, Katz LA. Are microbes fundamentally different than macroorganisms? Convergence and a possible case for neutral phenotypic evolution in testate amoeba (Amoebozoa: Arcellinida). R Soc Open Sci 2015; 2:150414. [PMID: 27019725 PMCID: PMC4807447 DOI: 10.1098/rsos.150414] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/17/2015] [Indexed: 06/05/2023]
Abstract
This study reveals extensive phenotypic convergence based on the non-monophyly of genera and morphospecies of testate (shelled) amoebae. Using two independent markers, small subunit ribosomal DNA (ssu-rDNA) and mitochondrial cytochrome oxidase I (COI), we demonstrate discordance between morphology and molecules for 'core Nebela' species (Arcellinida; Amoebozoa). Prior work using just a single locus, ssu-rDNA, also supported the non-monophyly of the genera Hyalosphenia and Nebela as well as for several morphospecies within these genera. Here, we obtained COI gene sequences of 59 specimens from seven morphospecies and ssu-rDNA gene sequences of 50 specimens from six morphospecies of hyalosphenids. Our analyses corroborate the prior ssu-rDNA findings of morphological convergence in test (shell) morphologies, as COI and ssu-rDNA phylogenies are concordant. Further, the monophyly of morphospecies is rejected using approximately unbiased tests. Given that testate amoebae are used as bioindicators in both palaeoecological and contemporary studies of threatened ecosystems such as bogs and fens, understanding the discordance between morphology and genetics in the hyalosphenids is essential for interpretation of indicator species. Further, while convergence is normally considered the result of natural selection, it is possible that neutrality underlies phenotypic evolution in these microorganisms.
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Affiliation(s)
- Angela M. Oliverio
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
| | - Daniel J. G. Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo 05508-090, Brazil
| | - Jessica Grant
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
| | - Laura A. Katz
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
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24
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Lahr DJG, Bosak T, Lara E, Mitchell EAD. The Phanerozoic diversification of silica-cycling testate amoebae and its possible links to changes in terrestrial ecosystems. PeerJ 2015; 3:e1234. [PMID: 26734499 PMCID: PMC4699787 DOI: 10.7717/peerj.1234] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 08/19/2015] [Indexed: 11/20/2022] Open
Abstract
The terrestrial cycling of Si is thought to have a large influence on the terrestrial and marine primary production, as well as the coupled biogeochemical cycles of Si and C. Biomineralization of silica is widespread among terrestrial eukaryotes such as plants, soil diatoms, freshwater sponges, silicifying flagellates and testate amoebae. Two major groups of testate (shelled) amoebae, arcellinids and euglyphids, produce their own silica particles to construct shells. The two are unrelated phylogenetically and acquired biomineralizing capabilities independently. Hyalosphenids, a group within arcellinids, are predators of euglyphids. We demonstrate that hyalosphenids can construct shells using silica scales mineralized by the euglyphids. Parsimony analyses of the current hyalosphenid phylogeny indicate that the ability to “steal” euglyphid scales is most likely ancestral in hyalosphenids, implying that euglyphids should be older than hyalosphenids. However, exactly when euglyphids arose is uncertain. Current fossil record contains unambiguous euglyphid fossils that are as old as 50 million years, but older fossils are scarce and difficult to interpret. Poor taxon sampling of euglyphids has also prevented the development of molecular clocks. Here, we present a novel molecular clock reconstruction for arcellinids and consider the uncertainties due to various previously used calibration points. The new molecular clock puts the origin of hyalosphenids in the early Carboniferous (∼370 mya). Notably, this estimate coincides with the widespread colonization of land by Si-accumulating plants, suggesting possible links between the evolution of Arcellinid testate amoebae and the expansion of terrestrial habitats rich in organic matter and bioavailable Si.
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Affiliation(s)
- Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo , Rua do Matão, São Paulo , Brazil
| | - Tanja Bosak
- Department of Earth, Atmospheric and Planetary Sciences, Massachussetts Institute of Technology , Cambridge, MA , USA
| | - Enrique Lara
- Laboratory of Soil Biology, University of Neuchatel , Neuchatel , Switzerland
| | - Edward A D Mitchell
- Laboratory of Soil Biology, University of Neuchatel, Neuchatel, Switzerland; Jardin Botanique de Neuchâtel, Neuchatel, Switzerland
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25
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Abstract
The Amoebozoa are a major eukaryotic lineage that encompasses a wide range of amoeboid organisms. The group is understudied from a systematic perspective: molecular tools have only been applied in the last 15 yr. Hence, there is an undersampling of both genes and taxa in the group especially compared to plants, animals, and fungi. Here, we present the complete mitochondrial genomes of two ubiquitous and abundant morpho-species (Acanthamoeba castellanii and Vermamoeba vermiformis). Both have mitochondrial genomes of close relatives previously available, enabling insights into recent divergences at a genomic scale, while simultaneously offering comparisons with divergence estimates obtained from traditionally used single genes, SSU rDNA and cox1. The newly sequenced mt genomes are significantly divergent from their previously sequenced conspecifics (A. castellannii 16.4% divergence at nucleotide level and 10.4% amino acid; V. vermiformis 21.6% and 13.1%, respectively), while divergence at the small subunit ribosomal DNA is below 1% within both species. Morphological analyses determined that these lineages are indistinguishable from their previously sequenced counterparts. Phylogenetic reconstructions using 26 mt genes also indicate a level of divergence that is comparable to divergence among species, while reconstructions using the small subunit ribosomal DNA (SSU rDNA) do not. In addition, we demonstrate that between closely related taxa, there are high levels of synteny, which can be explored for primer design to obtain larger fragments than the traditional barcoding genes. We conclude that, although most systematic work has relied on SSU, this gene alone can severely underestimate diversity. Thus, we suggest that the mt genome emerges as an alternative for unraveling the lower level phylogenetic relationships of Amoebozoa.
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Affiliation(s)
- Karolina Fučíková
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, USA
| | - Daniel J G Lahr
- Department of Zoology, Institute of Biosciences, University of São Paulo, São Paulo, 05508-090, Brazil
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26
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Lahr DJG, Grant J, Molestina R, Katz LA, Anderson OR. Sapocribrum chincoteaguense n. gen. n. sp.: A Small, Scale-bearing Amoebozoan with Flabellinid Affinities. J Eukaryot Microbiol 2015; 62:444-53. [PMID: 25515047 DOI: 10.1111/jeu.12199] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Revised: 09/24/2014] [Accepted: 10/30/2014] [Indexed: 11/29/2022]
Abstract
The isolate American Type Culture Collection (ATCC)® 50979™ is a small amoebozoan whose actin gene was previously characterized, but did not allow a stable phylogenetic placement. This isolate was originally mis-identified upon deposition, and subsequently mis-illustrated in a recent publication. Here, we provide both a detailed morphological description as well as additional molecular analyses in order to clarify the isolate's phylogenetic relationships. The amoeba is minute (less than 5 μm), and presents the behavior of staying in a fixed location, while emitting one or two thin pseudopods. Transmission electron microscopy reveals that the cell is covered in a layer with embedded scales, giving the cell an armored appearance. Molecular phylogenetic analyses of data (actin, alpha- and beta-tubulin, elongation factor 2, and 14-3-3) from transcriptomes of this and four other isolates reveals that ATCC® 50979(™) is closely related to the recently described Squamamoeba japonica and in a novel, stable clade. Due to the unique nature of the scale covering, as well as other gross morphological characters and the molecular phylogenetic analyses, we formally describe the isolate as Sapocribrum chincoteaguense n. gen. n. sp.
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Affiliation(s)
- Daniel J G Lahr
- Department of Zoology, University of São Paulo, 05508-090, São Paulo, Brazil.,Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - Jessica Grant
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - Robert Molestina
- Protistology Collection, American Type Culture Collection, Manassas, Virginia, 20110, USA
| | - Laura A Katz
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, 01063, USA
| | - O Roger Anderson
- Department of Biology, Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, 10964, USA
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27
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Lahr DJG, Laughinghouse HD, Oliverio AM, Gao F, Katz LA. How discordant morphological and molecular evolution among microorganisms can revise our notions of biodiversity on Earth. Bioessays 2014; 36:950-9. [PMID: 25156897 DOI: 10.1002/bies.201400056] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Microscopy has revealed tremendous diversity of bacterial and eukaryotic forms. Recent molecular analyses show discordance in estimates of biodiversity between morphological and molecular analyses. Moreover, phylogenetic analyses of the diversity of microbial forms reveal evidence of convergence at scales as deep as interdomain: morphologies shared between bacteria and eukaryotes. Here, we highlight examples of such discordance, focusing on exemplary lineages such as testate amoebae, ciliates, and cyanobacteria. These have long histories of morphological study, enabling deeper analyses on both the molecular and morphological sides. We discuss examples in two main categories: (i) morphologically identical (or highly similar) individuals that are genetically distinct and (ii) morphologically distinct individuals that are genetically the same. We argue that hypotheses about discordance can be tested using the concept of neutral morphologies, or more broadly neutral phenotypes, as a null hypothesis.
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Affiliation(s)
- Daniel J G Lahr
- Department of Zoology, University of Sao Paulo, Sao Paulo, Brazil
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28
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Lahr DJG, Grant JR, Katz LA. Multigene phylogenetic reconstruction of the Tubulinea (Amoebozoa) corroborates four of the six major lineages, while additionally revealing that shell composition does not predict phylogeny in the Arcellinida. Protist 2013; 164:323-39. [PMID: 23499265 DOI: 10.1016/j.protis.2013.02.003] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2012] [Revised: 02/08/2013] [Accepted: 02/11/2013] [Indexed: 10/27/2022]
Abstract
Tubulinea is a phylogenetically stable higher-level taxon within Amoebozoa, morphologically characterized by monoaxially streaming and cylindrical pseudopods. Contemporary phylogenetic reconstructions have largely relied on SSU rDNA, and to a lesser extent, on actin genes to reveal the relationships among these organisms. Additionally, the test (shell) forming Arcellinida, one of the most species-rich amoebozoan groups, is nested within Tubulinea and suffers from substantial under-sampling of taxa. Here, we increase taxonomic and gene sampling within the Tubulinea, characterizing molecular data for 22 taxa and six genes (SSU rDNA, actin, α- and β-tubulin, elongation factor 2 and the 14-3-3 regulatory protein). We perform concatenated phylogenetic analyses using these genes as well as approximately unbiased tests to assess evolutionary relationships within the Tubulinea. We confirm the monophyly of Tubulinea and four of the six included lineages (Echinamoeboidea, Leptomyxida, Amoebida and Poseidonida). Arcellinida and Hartmanellidae, the remaining lineages, are not monophyletic in our reconstructions, although statistical testing does not allow rejection of either group. We further investigate more fine-grained morphological evolution of previously defined groups, concluding that relationships within Arcellinida are more consistent with general test and aperture shape than with test composition. We also discuss the implications of this phylogeny for interpretations of the Precambrian fossil record of testate amoebae.
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Affiliation(s)
- Daniel J G Lahr
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts 01003, USA.
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29
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Parfrey LW, Lahr DJG. Multicellularity arose several times in the evolution of eukaryotes (Response to DOI 10.1002/bies.201100187). Bioessays 2013; 35:339-47. [DOI: 10.1002/bies.201200143] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Affiliation(s)
- Daniel J. G. Lahr
- Department of Zoology; University of São Paulo; Rua do Matão Travessa 14, #101 05508-090 São Paulo Brazil
| | - Enrique Lara
- Laboratory of Soil Biology; University of Neuchâtel; Rue Emile-Argand 11 CH-2000 Neuchâtel Switzerland
| | - Edward A. D. Mitchell
- Laboratory of Soil Biology; University of Neuchâtel; Rue Emile-Argand 11 CH-2000 Neuchâtel Switzerland
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31
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Lahr DJG, Grant J, Nguyen T, Lin JH, Katz LA. Comprehensive phylogenetic reconstruction of amoebozoa based on concatenated analyses of SSU-rDNA and actin genes. PLoS One 2011; 6:e22780. [PMID: 21829512 PMCID: PMC3145751 DOI: 10.1371/journal.pone.0022780] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2011] [Accepted: 07/06/2011] [Indexed: 11/18/2022] Open
Abstract
Evolutionary relationships within Amoebozoa have been the subject of controversy for two reasons: 1) paucity of morphological characters in traditional surveys and 2) haphazard taxonomic sampling in modern molecular reconstructions. These along with other factors have prevented the erection of a definitive system that resolves confidently both higher and lower-level relationships. Additionally, the recent recognition that many protosteloid amoebae are in fact scattered throughout the Amoebozoa suggests that phylogenetic reconstructions have been excluding an extensive and integral group of organisms. Here we provide a comprehensive phylogenetic reconstruction based on 139 taxa using molecular information from both SSU-rDNA and actin genes. We provide molecular data for 13 of those taxa, 12 of which had not been previously characterized. We explored the dataset extensively by generating 18 alternative reconstructions that assess the effect of missing data, long-branched taxa, unstable taxa, fast evolving sites and inclusion of environmental sequences. We compared reconstructions with each other as well as against previously published phylogenies. Our analyses show that many of the morphologically established lower-level relationships (defined here as relationships roughly equivalent to Order level or below) are congruent with molecular data. However, the data are insufficient to corroborate or reject the large majority of proposed higher-level relationships (above the Order-level), with the exception of Tubulinea, Archamoebae and Myxogastrea, which are consistently recovered. Moreover, contrary to previous expectations, the inclusion of available environmental sequences does not significantly improve the Amoebozoa reconstruction. This is probably because key amoebozoan taxa are not easily amplified by environmental sequencing methodology due to high rates of molecular evolution and regular occurrence of large indels and introns. Finally, in an effort to facilitate future sampling of key amoebozoan taxa, we provide a novel methodology for genome amplification and cDNA extraction from single or a few cells, a method that is culture-independent and allows both photodocumentation and extraction of multiple genes from natural samples.
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Affiliation(s)
- Daniel J. G. Lahr
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Jessica Grant
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Truc Nguyen
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Jian Hua Lin
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
| | - Laura A. Katz
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, Massachusetts, United States of America
- Department of Biological Sciences, Smith College, Northampton, Massachusetts, United States of America
- * E-mail:
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32
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Lahr DJG, Parfrey LW, Mitchell EAD, Katz LA, Lara E. The chastity of amoebae: re-evaluating evidence for sex in amoeboid organisms. Proc Biol Sci 2011; 278:2081-90. [PMID: 21429931 PMCID: PMC3107637 DOI: 10.1098/rspb.2011.0289] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 03/04/2011] [Indexed: 11/12/2022] Open
Abstract
Amoebae are generally assumed to be asexual. We argue that this view is a relict of early classification schemes that lumped all amoebae together inside the 'lower' protozoa, separated from the 'higher' plants, animals and fungi. This artificial classification allowed microbial eukaryotes, including amoebae, to be dismissed as primitive, and implied that the biological rules and theories developed for macro-organisms need not apply to microbes. Eukaryotic diversity is made up of 70+ lineages, most of which are microbial. Plants, animals and fungi are nested among these microbial lineages. Thus, theories on the prevalence and maintenance of sex developed for macro-organisms should in fact apply to microbial eukaryotes, though the theories may need to be refined and generalized (e.g. to account for the variation in sexual strategies and prevalence of facultative sex in natural populations of many microbial eukaryotes). We use a revised phylogenetic framework to assess evidence for sex in several amoeboid lineages that are traditionally considered asexual, and we interpret this evidence in light of theories on the evolution of sex developed for macro-organisms. We emphasize that the limited data available for many lineages coupled with natural variation in microbial life cycles overestimate the extent of asexuality. Mapping sexuality onto the eukaryotic tree of life demonstrates that the majority of amoeboid lineages are, contrary to popular belief, anciently sexual, and that most asexual groups have probably arisen recently and independently. Additionally, several unusual genomic traits are prevalent in amoeboid lineages, including cyclic polyploidy, which may serve as alternative mechanisms to minimize the deleterious effects of asexuality.
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Affiliation(s)
- Daniel J. G. Lahr
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Laura Wegener Parfrey
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Edward A. D. Mitchell
- Laboratory of Soil Biology, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
| | - Laura A. Katz
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA
- Department of Biological Sciences, Smith College, Northampton, MA 01063, USA
| | - Enrique Lara
- Laboratory of Soil Biology, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000 Neuchâtel, Switzerland
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33
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Abstract
Amoebae are generally assumed to be asexual. We argue that this view is a relict of early classification schemes that lumped all amoebae together inside the 'lower' protozoa, separated from the 'higher' plants, animals and fungi. This artificial classification allowed microbial eukaryotes, including amoebae, to be dismissed as primitive, and implied that the biological rules and theories developed for macro-organisms need not apply to microbes. Eukaryotic diversity is made up of 70+ lineages, most of which are microbial. Plants, animals and fungi are nested among these microbial lineages. Thus, theories on the prevalence and maintenance of sex developed for macro-organisms should in fact apply to microbial eukaryotes, though the theories may need to be refined and generalized (e.g. to account for the variation in sexual strategies and prevalence of facultative sex in natural populations of many microbial eukaryotes). We use a revised phylogenetic framework to assess evidence for sex in several amoeboid lineages that are traditionally considered asexual, and we interpret this evidence in light of theories on the evolution of sex developed for macro-organisms. We emphasize that the limited data available for many lineages coupled with natural variation in microbial life cycles overestimate the extent of asexuality. Mapping sexuality onto the eukaryotic tree of life demonstrates that the majority of amoeboid lineages are, contrary to popular belief, anciently sexual, and that most asexual groups have probably arisen recently and independently. Additionally, several unusual genomic traits are prevalent in amoeboid lineages, including cyclic polyploidy, which may serve as alternative mechanisms to minimize the deleterious effects of asexuality.
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Affiliation(s)
- Daniel J G Lahr
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA.
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34
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Lahr DJG, Nguyen TB, Barbero E, Katz LA. Evolution of the actin gene family in testate lobose amoebae (Arcellinida) is characterized by two distinct clades of paralogs and recent independent expansions. Mol Biol Evol 2010; 28:223-36. [PMID: 20679092 DOI: 10.1093/molbev/msq200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The evolution of actin gene families is characterized by independent expansions and contractions across the eukaryotic tree of life. Here, we assess diversity of actin gene sequences within three lineages of the genus Arcella, a free-living testate (shelled) amoeba in the Arcellinida. We established four clonal lines of two morphospecies, Arcella hemisphaerica and A. vulgaris, and assessed their phylogenetic relationship within the "Amoebozoa" using small subunit ribosomal DNA (SSU-rDNA) genealogy. We determined that the two lines of A. hemisphaerica are identical in SSU-rDNA, while the two A. vulgaris are independent genetic lineages. Furthermore, we characterized multiple actin gene copies from all lineages. Analyses of the resulting sequences reveal numerous diverse actin genes, which differ mostly by synonymous substitutions. We estimate that the actin gene family contains 40-50 paralogous members in each lineage. None of the three independent lineages share the same paralog with another, and divergence between actins reaches 29% in contrast to just 2% in SSU-rDNA. Analyses of effective number of codons (ENC), compositional bias, recombination signatures, and genetic diversity in the context of a gene tree indicate that there are two groups of actins evolving with distinct patterns of molecular evolution. Within these groups, there have been multiple independent expansions of actin genes within each lineage. Together, these data suggest that the two groups are located in different regions of the Arcella genome. Furthermore, we compare the Arcella actin gene family with the relatively well-described gene family in the slime mold Dictyostelium discoideum and other members of the Amoebozoa clade. Overall patterns of molecular evolution are similar in Arcella and Dictyostelium. However, the separation of genes in two distinct groups coupled with recent expansion is characteristic of Arcella and might reflect an unusual pattern of gene family evolution in the lobose testate amoebae. We provide a model to account for both the existence of two distinct groups and the pattern of recent independent expansion leading to a large number of actins in each lineage.
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Affiliation(s)
- Daniel J G Lahr
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts
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35
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Lahr DJG, Katz LA. Reducing the impact of PCR-mediated recombination in molecular evolution and environmental studies using a new-generation high-fidelity DNA polymerase. Biotechniques 2010; 47:857-66. [PMID: 19852769 DOI: 10.2144/000113219] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
PCR-mediated recombination can greatly impact estimates of diversity, both in environmental studies and in analyses of gene family evolution. Here we measure chimera (PCR-mediated recombinant) formation by analyzing a mixture of eight partial actin sequences isolated from the amoeba Arcella hemisphaerica amplified under a variety of conditions that mimic standard laboratory situations. We further compare a new-generation proofreading processivity-enhanced polymerase to both a standard proofreading enzyme and previously published results. Proofreading polymerases are preferred over other polymerases in instances where evolutionary inferences must be made. Our analyses reveal that reducing the initial template concentration is as critical as reducing the number of cycles for decreasing chimera formation and improving accuracy. Furthermore, assessing the efficiency of recovery of original haplotypes demonstrates that multiple PCR reactions are required to capture the actual genetic diversity of a sample. Finally, the experiments confirm that processivity-enhanced polymerases enable a substantial decrease in PCR-mediated recombination through reducing starting template concentration, without compromising the robustness of PCR reactions.
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Affiliation(s)
- Daniel J G Lahr
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA 01003, USA.
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36
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Abstract
Analyses of diverse eukaryotes reveal that genomes are dynamic, sometimes dramatically so. In numerous lineages across the eukaryotic tree of life, DNA content varies within individuals throughout life cycles and among individuals within species. Discovery of examples of genome dynamism is accelerating as genome sequences are completed from diverse eukaryotes. Though much is known about genomes in animals, fungi, and plants, these lineages represent only 3 of the 60-200 lineages of eukaryotes. Here, we discuss diverse genomic strategies in exemplar eukaryotic lineages, including numerous microbial eukaryotes, to reveal dramatic variation that challenges established views of genome evolution. For example, in the life cycle of some members of the "radiolaria," ploidy increases from haploid (N) to approximately 1,000N, whereas intrapopulation variability of the enteric parasite Entamoeba ranges from 4N to 40N. Variation has also been found within our own species, with substantial differences in both gene content and chromosome lengths between individuals. Data on the dynamic nature of genomes shift the perception of the genome from being fixed and characteristic of a species (typological) to plastic due to variation within and between species.
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