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Morrissette N, Abbaali I, Ramakrishnan C, Hehl AB. The Tubulin Superfamily in Apicomplexan Parasites. Microorganisms 2023; 11:microorganisms11030706. [PMID: 36985278 PMCID: PMC10056924 DOI: 10.3390/microorganisms11030706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 03/03/2023] [Accepted: 03/06/2023] [Indexed: 03/11/2023] Open
Abstract
Microtubules and specialized microtubule-containing structures are assembled from tubulins, an ancient superfamily of essential eukaryotic proteins. Here, we use bioinformatic approaches to analyze features of tubulins in organisms from the phylum Apicomplexa. Apicomplexans are protozoan parasites that cause a variety of human and animal infectious diseases. Individual species harbor one to four genes each for α- and β-tubulin isotypes. These may specify highly similar proteins, suggesting functional redundancy, or exhibit key differences, consistent with specialized roles. Some, but not all apicomplexans harbor genes for δ- and ε-tubulins, which are found in organisms that construct appendage-containing basal bodies. Critical roles for apicomplexan δ- and ε-tubulin are likely to be limited to microgametes, consistent with a restricted requirement for flagella in a single developmental stage. Sequence divergence or the loss of δ- and ε-tubulin genes in other apicomplexans appears to be associated with diminished requirements for centrioles, basal bodies, and axonemes. Finally, because spindle microtubules and flagellar structures have been proposed as targets for anti-parasitic therapies and transmission-blocking strategies, we discuss these ideas in the context of tubulin-based structures and tubulin superfamily properties.
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Affiliation(s)
- Naomi Morrissette
- Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697, USA
- Correspondence: ; Tel.: +1-949-824-9243
| | - Izra Abbaali
- Molecular Biology and Biochemistry, University of California Irvine, Irvine, CA 92697, USA
| | - Chandra Ramakrishnan
- Institute for Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057 Zürich, Switzerland
| | - Adrian B. Hehl
- Institute for Parasitology, University of Zurich, Winterthurerstrasse 266a, 8057 Zürich, Switzerland
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2
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The characterization of novel monomeric creatine kinases in the early branching Alveolata species, Perkinsus marinus: Implications for phosphagen kinase evolution. Comp Biochem Physiol B Biochem Mol Biol 2022; 262:110758. [PMID: 35598705 DOI: 10.1016/j.cbpb.2022.110758] [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: 03/07/2022] [Revised: 05/14/2022] [Accepted: 05/16/2022] [Indexed: 11/20/2022]
Abstract
The genome of the unicellular molluscan parasite Perkinsus marinus contains at least five genes coding for putative creatine kinases (CK), a phosphoryl transfer enzyme which plays a key role in cellular energy transactions. Expression and kinetic analyses of three of the P. marinus CKs revealed them to be true CKs with catalytic properties in the range of typical metazoan CKs. A sequence comparison of the P. marinus CKs with a range of CK dimers and other dimeric phosphoryl transfer enzymes in this family (phosphagen kinases) showed that the P. marinus CKs lacked some of the critical residues involved in dimer stabilization, a trait all previously characterized CKs share. Size exclusion chromatography of all three expressed P. marinus CK constructs indicated they are monomeric, consistent with the observed lack of some critical dimer stabilizing residues. Phylogenetic analyses of the P. marinus CKs and putative dinoflagellate CKs with a broad range of monomeric and dimeric phosphagen kinases revealed that the Perkinsus CKs form a distinct, well-supported clade with dinoflagellate CKs which also lack the dimer stabilizing residues. Analysis of the genomic data for P. marinus showed the presence of putative genes for the two enzymes associated with creatine biosynthesis. CK in higher organisms plays a critical role in energy buffering in cell types displaying high and variable rates of ATP turnover. The presence of multiple CKs and the creatine biosynthetic pathway in P. marinus indicates that this unicellular parasite has the full complement of molecular machinery for CK-mediated energy buffering.
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Itoïz S, Metz S, Derelle E, Reñé A, Garcés E, Bass D, Soudant P, Chambouvet A. Emerging Parasitic Protists: The Case of Perkinsea. Front Microbiol 2022; 12:735815. [PMID: 35095782 PMCID: PMC8792838 DOI: 10.3389/fmicb.2021.735815] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Accepted: 11/25/2021] [Indexed: 11/13/2022] Open
Abstract
The last century has witnessed an increasing rate of new disease emergence across the world leading to permanent loss of biodiversity. Perkinsea is a microeukaryotic parasitic phylum composed of four main lineages of parasitic protists with broad host ranges. Some of them represent major ecological and economical threats because of their geographically invasive ability and pathogenicity (leading to mortality events). In marine environments, three lineages are currently described, the Parviluciferaceae, the Perkinsidae, and the Xcellidae, infecting, respectively, dinoflagellates, mollusks, and fish. In contrast, only one lineage is officially described in freshwater environments: the severe Perkinsea infectious agent infecting frog tadpoles. The advent of high-throughput sequencing methods, mainly based on 18S rRNA assays, showed that Perkinsea is far more diverse than the previously four described lineages especially in freshwater environments. Indeed, some lineages could be parasites of green microalgae, but a formal nature of the interaction needs to be explored. Hence, to date, most of the newly described aquatic clusters are only defined by their environmental sequences and are still not (yet) associated with any host. The unveiling of this microbial black box presents a multitude of research challenges to understand their ecological roles and ultimately to prevent their most negative impacts. This review summarizes the biological and ecological traits of Perkinsea-their diversity, life cycle, host preferences, pathogenicity, and highlights their diversity and ubiquity in association with a wide range of hosts.
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Affiliation(s)
- Sarah Itoïz
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, Plouzané, France
| | | | | | - Albert Reñé
- Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta, Barcelona, Spain
| | - Esther Garcés
- Departament de Biologia Marina i Oceanografia, Institut de Ciències del Mar, CSIC, Pg. Marítim de la Barceloneta, Barcelona, Spain
| | - David Bass
- Centre for Environment, Fisheries and Aquaculture Science (Cefas), Weymouth, United Kingdom
- Department of Life Sciences, The Natural History Museum, London, United Kingdom
- Biosciences, University of Exeter, Exeter, United Kingdom
| | | | - Aurélie Chambouvet
- Univ Brest, CNRS, IRD, Ifremer, LEMAR, Plouzané, France
- Sorbonne Université, CNRS, UMR 7144 Adaptation et Diversité en Milieu Marin, Ecology of Marine Plankton (ECOMAP), Station Biologique de Roscoff SBR, Roscoff, France
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Elisafenko EA, Evtushenko EV, Vershinin AV. The origin and evolution of a two-component system of paralogous genes encoding the centromeric histone CENH3 in cereals. BMC PLANT BIOLOGY 2021; 21:541. [PMID: 34794377 PMCID: PMC8603533 DOI: 10.1186/s12870-021-03264-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 10/12/2021] [Indexed: 06/07/2023]
Abstract
BACKGROUND The cereal family Poaceae is one of the largest and most diverse angiosperm families. The central component of centromere specification and function is the centromere-specific histone H3 (CENH3). Some cereal species (maize, rice) have one copy of the gene encoding this protein, while some (wheat, barley, rye) have two. We applied a homology-based approach to sequenced cereal genomes, in order to finally trace the mutual evolution of the structure of the CENH3 genes and the nearby regions in various tribes. RESULTS We have established that the syntenic group or the CENH3 locus with the CENH3 gene and the boundaries defined by the CDPK2 and bZIP genes first appeared around 50 Mya in a common ancestor of the subfamilies Bambusoideae, Oryzoideae and Pooideae. This locus came to Pooideae with one copy of CENH3 in the most ancient tribes Nardeae and Meliceae. The βCENH3 gene as a part of the locus appeared in the tribes Stipeae and Brachypodieae around 35-40 Mya. The duplication was accompanied by changes in the exon-intron structure. Purifying selection acts mostly on αCENH3s, while βCENH3s form more heterogeneous structures, in which clade-specific amino acid motifs are present. In barley species, the βCENH3 gene assumed an inverted orientation relative to αCENH3 and the CDPK2 gene was substituted with LHCB-l. As the evolution and domestication of plant species went on, the locus was growing in size due to an increasing distance between αCENH3 and βCENH3 because of a massive insertion of the main LTR-containing retrotransposon superfamilies, gypsy and copia, without any evolutionary preference on either of them. A comparison of the molecular structure of the locus in the A, B and D subgenomes of the hexaploid wheat T. aestivum showed that invasion by mobile elements and concomitant rearrangements took place in an independent way even in evolutionarily close species. CONCLUSIONS The CENH3 duplication in cereals was accompanied by changes in the exon-intron structure of the βCENH3 paralog. The observed general tendency towards the expansion of the CENH3 locus reveals an amazing diversity of ways in which different species implement the scenario described in this paper.
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Affiliation(s)
- Evgeny A Elisafenko
- Institute of Cytology and Genetics, SB RAS, Novosibirsk, 630090, Russia
- Institute of Molecular and Cellular Biology, SB RAS, Novosibirsk, 630090, Russia
| | - Elena V Evtushenko
- Institute of Molecular and Cellular Biology, SB RAS, Novosibirsk, 630090, Russia
| | - Alexander V Vershinin
- Institute of Molecular and Cellular Biology, SB RAS, Novosibirsk, 630090, Russia.
- Novosibirsk State University, Novosibirsk, 630090, Russia.
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5
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Einarsson E, Lassadi I, Zielinski J, Guan Q, Wyler T, Pain A, Gornik SG, Waller RF. Development of the Myzozoan Aquatic Parasite Perkinsus marinus as A Versatile Experimental Genetic Model Organism. Protist 2021; 172:125830. [PMID: 34555729 DOI: 10.1016/j.protis.2021.125830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/14/2021] [Accepted: 07/15/2021] [Indexed: 11/17/2022]
Abstract
The phylum Perkinsozoa is an aquatic parasite lineage that has devastating effects on commercial and natural mollusc populations, and also comprises parasites of algae, fish and amphibians. They are related to dinoflagellates and apicomplexans and thus offer excellent genetic models for both parasitological and evolutionary studies. Genetic transformation was previously achieved for Perkinsus spp. but with few tools for transgene expression and limited selection efficacy. We sought to expand the power of experimental genetic tools for Perkinsus using P. marinus as a model. We constructed a modular plasmid assembly system for expression of multiple genes simultaneously. We developed efficient selection systems for three drugs, puromycin, bleomycin and blasticidin, that are effective in as little as three weeks. We developed eleven new promoters of variable expression strength. Furthermore, we identified that genomic integration of transgenes is predominantly via non-homologous recombination but with transgene fragmentation including deletion of some elements. To counter these dynamic processes, we show that bi-cistronic transcripts using the viral 2A peptides can couple selection to the maintenance of the expression of a transgene of interest. Collectively, these new tools and insights provide great new capacity to genetically modify and study Perkinsus as an aquatic parasite and evolutionary model.
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Affiliation(s)
- Elin Einarsson
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Imen Lassadi
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Jana Zielinski
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Qingtian Guan
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Tobias Wyler
- Department of Biochemistry, University of Cambridge, Cambridge, UK; Eidgenössische Technische Hochschule (ETH), Zürich, Switzerland
| | - Arnab Pain
- Biological and Environmental Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
| | - Sebastian G Gornik
- Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany
| | - Ross F Waller
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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6
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Sparvoli D, Lebrun M. Unraveling the Elusive Rhoptry Exocytic Mechanism of Apicomplexa. Trends Parasitol 2021; 37:622-637. [PMID: 34045149 DOI: 10.1016/j.pt.2021.04.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 12/11/2022]
Abstract
Apicomplexan parasites are unicellular eukaryotes that invade the cells in which they proliferate. The development of genetic tools in Toxoplasma, and then in Plasmodium, in the 1990s allowed the first description of the molecular machinery used for motility and invasion, revealing a crucial role for two different secretory organelles, micronemes and rhoptries. Rhoptry proteins are injected directly into the host cytoplasm not only to promote invasion but also to manipulate host functions. Nonetheless, the injection machinery has remained mysterious, a major conundrum in the field. Here we review recent progress in uncovering structural components and proteins implicated in rhoptry exocytosis and explain how revisiting early findings and considering the evolutionary origins of Apicomplexa contributed to some of these discoveries.
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Affiliation(s)
- Daniela Sparvoli
- LPHI UMR5235, Univ Montpellier, CNRS, F-34095 Montpellier, France
| | - Maryse Lebrun
- LPHI UMR5235, Univ Montpellier, CNRS, F-34095 Montpellier, France.
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Zhang M, Cui Z, Liu F, Chen N. Definition of a High-Resolution Molecular Marker for Tracking the Genetic Diversity of the Harmful Algal Species Eucampia zodiacus Through Comparative Analysis of Mitochondrial Genomes. Front Microbiol 2021; 12:631144. [PMID: 33841358 PMCID: PMC8024477 DOI: 10.3389/fmicb.2021.631144] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Accepted: 02/23/2021] [Indexed: 11/13/2022] Open
Abstract
The cosmopolitan phytoplankton species Eucampia zodiacus is a common harmful algal bloom (HAB) species that have been found to cause HABs in essentially all coastal regions except the Polar regions. However, molecular information for this HAB species is limited with only a few molecular markers. In this project, we constructed the mitochondrial genome (mtDNA) of E. zodiacus, which was also the first mtDNA constructed for any species in the order Hemiaulales that includes 145 reported species (including two additional HAB species Cerataulina bicornis and Cerataulina pelagica). Comparative analysis of eight E. zodiacus strains revealed that they could not be distinguished using common molecular markers, suggesting that common molecular markers do not have adequate resolution for distinguishing E. zodiacus strains. However, these E. zodiacus strains could be distinguished using whole mtDNAs, suggesting the presence of different genotypes due to evolutionary divergence. Through comparative analysis of the mtDNAs of multiple E. zodiacus strains, we identified a new molecular marker ezmt1 that could adequately distinguish different E. zodiacus strains isolated in various coastal regions in China. This molecular marker ezmt1, which was ∼400 bp in size, could be applied to identify causative genotypes during E. zodiacus HABs through tracking the dynamic changes of genetic diversity of E. zodiacus in HABs.
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Affiliation(s)
- Mengjia Zhang
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Institute of Oceanology, University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Zongmei Cui
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Institute of Oceanology, University of Chinese Academy of Sciences, Beijing, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Feng Liu
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China
| | - Nansheng Chen
- CAS Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.,Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, China.,Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
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8
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Gottschling M, Czech L, Mahé F, Adl S, Dunthorn M. The Windblown: Possible Explanations for Dinophyte DNA in Forest Soils. J Eukaryot Microbiol 2020; 68:e12833. [PMID: 33155377 DOI: 10.1111/jeu.12833] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 10/12/2020] [Accepted: 10/28/2020] [Indexed: 11/28/2022]
Abstract
Dinophytes are widely distributed in marine- and fresh-waters, but have yet to be conclusively documented in terrestrial environments. Here, we evaluated the presence of these protists from an environmental DNA metabarcoding dataset of Neotropical rainforest soils. Using a phylogenetic placement approach with a reference alignment and tree, we showed that the numerous sequencing reads that were phylogenetically placed as dinophytes did not correlate with taxonomic assignment, environmental preference, nutritional mode, or dormancy. All the dinophytes in the soils are rather windblown dispersal units of aquatic species and are not biologically active residents of terrestrial environments.
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Affiliation(s)
- Marc Gottschling
- Department Biologie, Systematische Botanik und Mykologie, GeoBio-Center, Ludwig-Maximilians-Universität München, Munich, D-80638, Germany
| | - Lucas Czech
- Computational Molecular Evolution Group, Heidelberg Institute for Theoretical Studies, Heidelberg, D-69118, Germany.,Department of Plant Biology, Carnegie Institution for Science, Stanford, California, 94305, USA
| | - Frédéric Mahé
- CIRAD, UMR BGPI, Montpellier, F-34398, France.,BGPI, Université de Montpellier, CIRAD, IRD, Montpellier SupAgro, , Montpellier, France
| | - Sina Adl
- Department of Soil Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, SK, S7N 5A8, Canada
| | - Micah Dunthorn
- Eukaryotic Microbiology, Faculty of Biology, Universität Duisburg-Essen, Essen, D-45141, Germany.,Centre for Water and Environmental Research (ZWU), Universität Duisburg-Essen, Essen, D-45141, Germany
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9
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Sprecher BN, Zhang H, Lin S. Nuclear Gene Transformation in the Dinoflagellate Oxyrrhis marina. Microorganisms 2020; 8:E126. [PMID: 31963386 PMCID: PMC7022241 DOI: 10.3390/microorganisms8010126] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 01/10/2020] [Accepted: 01/14/2020] [Indexed: 11/16/2022] Open
Abstract
The lack of a robust gene transformation tool that allows proper expression of foreign genes and functional testing for the vast number of nuclear genes in dinoflagellates has greatly hampered our understanding of the fundamental biology in this ecologically important and evolutionarily unique lineage of microeukaryotes. Here, we report the development of a dinoflagellate expression vector containing various DNA elements from phylogenetically separate dinoflagellate lineages, an electroporation protocol, and successful expression of introduced genes in an early branching dinoflagellate, Oxyrrhis marina. This protocol, involving the use of Lonza's Nucleofector and a codon-optimized antibiotic resistance gene, has been successfully used to produce consistent results in several independent experiments for O. marina. It is anticipated that this protocol will be adaptable for other dinoflagellates and will allow characterization of many novel dinoflagellate genes.
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Affiliation(s)
| | - Huan Zhang
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Rd, Groton, CT 06340, USA;
| | - Senjie Lin
- Department of Marine Sciences, University of Connecticut, 1080 Shennecossett Rd, Groton, CT 06340, USA;
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10
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Xue Q. Pathogen proteases and host protease inhibitors in molluscan infectious diseases. J Invertebr Pathol 2019; 166:107214. [PMID: 31348922 DOI: 10.1016/j.jip.2019.107214] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 04/11/2019] [Accepted: 06/28/2019] [Indexed: 12/17/2022]
Abstract
The development of infectious diseases represents an outcome of dynamic interactions between the disease-producing agent's pathogenicity and the host's self-defense mechanism. Proteases secreted by pathogenic microorganisms and protease inhibitors produced by host species play an important role in the process. This review aimed at summarizing major findings in research on pathogen proteases and host protease inhibitors that had been proposed to be related to the development of mollusk diseases. Metalloproteases and serine proteases respectively belonging to Family M4 and Family S8 of the MEROPS system are among the most studied proteases that may function as virulence factors in mollusk pathogens. On the other hand, a mollusk-specific family (Family I84) of novel serine protease inhibitors and homologues of the tissue inhibitor of metalloprotease have been studied for their potential in the molluscan host defense. In addition, research at the genomic and transcriptomic levels showed that more proteases of pathogens and protease inhibitor of hosts are likely involved in mollusk disease processes. Therefore, the pathological significance of interactions between pathogen proteases and host protease inhibitors in the development of molluscan infectious diseases deserves more research efforts.
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Affiliation(s)
- Qinggang Xue
- Zhejiang Key Lab of Aquatic Germplasm Resources, Zhejiang Wanli University, Ningbo, Zhejiang 315100, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China.
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11
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Schott EJ, Di Lella S, Bachvaroff TR, Amzel LM, Vasta GR. Lacking catalase, a protistan parasite draws on its photosynthetic ancestry to complete an antioxidant repertoire with ascorbate peroxidase. BMC Evol Biol 2019; 19:146. [PMID: 31324143 PMCID: PMC6642578 DOI: 10.1186/s12862-019-1465-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 06/24/2019] [Indexed: 01/06/2023] Open
Abstract
Background Antioxidative enzymes contribute to a parasite’s ability to counteract the host’s intracellular killing mechanisms. The facultative intracellular oyster parasite, Perkinsus marinus, a sister taxon to dinoflagellates and apicomplexans, is responsible for mortalities of oysters along the Atlantic coast of North America. Parasite trophozoites enter molluscan hemocytes by subverting the phagocytic response while inhibiting the typical respiratory burst. Because P. marinus lacks catalase, the mechanism(s) by which the parasite evade the toxic effects of hydrogen peroxide had remained unclear. We previously found that P. marinus displays an ascorbate-dependent peroxidase (APX) activity typical of photosynthetic eukaryotes. Like other alveolates, the evolutionary history of P. marinus includes multiple endosymbiotic events. The discovery of APX in P. marinus raised the questions: From which ancestral lineage is this APX derived, and what role does it play in the parasite’s life history? Results Purification of P. marinus cytosolic APX activity identified a 32 kDa protein. Amplification of parasite cDNA with oligonucleotides corresponding to peptides of the purified protein revealed two putative APX-encoding genes, designated PmAPX1 and PmAPX2. The predicted proteins are 93% identical, and PmAPX2 carries a 30 amino acid N-terminal extension relative to PmAPX1. The P. marinus APX proteins are similar to predicted APX proteins of dinoflagellates, and they more closely resemble chloroplastic than cytosolic APX enzymes of plants. Immunofluorescence for PmAPX1 and PmAPX2 shows that PmAPX1 is cytoplasmic, while PmAPX2 is localized to the periphery of the central vacuole. Three-dimensional modeling of the predicted proteins shows pronounced differences in surface charge of PmAPX1 and PmAPX2 in the vicinity of the aperture that provides access to the heme and active site. Conclusions PmAPX1 and PmAPX2 phylogenetic analysis suggests that they are derived from a plant ancestor. Plant ancestry is further supported by the presence of ascorbate synthesis genes in the P. marinus genome that are similar to those in plants. The localizations and 3D structures of the two APX isoforms suggest that APX fulfills multiple functions in P. marinus within two compartments. The possible role of APX in free-living and parasitic stages of the life history of P. marinus is discussed. Electronic supplementary material The online version of this article (10.1186/s12862-019-1465-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Eric J Schott
- Department of Microbiology & Immunology, University of Maryland School of Medicine, and Institute of Marine and Environmental Technology, 701 E. Pratt Street, Baltimore, MD, 21202, USA.,Present address: University of Maryland Center for Environmental Science, Institute of Marine and Environmental Technology, 701 E. Pratt Street, Baltimore, MD, 21202, USA
| | - Santiago Di Lella
- Instituto de Química Biológica - Ciencias Exactas y Naturales, IQUIBICEN / CONICET, Departamento de Química Biológica, Fac. de Cs. Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Capital Federal, Argentina
| | - Tsvetan R Bachvaroff
- University of Maryland Center for Environmental Science, Institute of Marine and Environmental Technology, 701 E. Pratt Street, Baltimore, MD, 21202, USA
| | - L Mario Amzel
- Department of Biophysics & Biophysical Chemistry, The Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD, 21205, USA
| | - Gerardo R Vasta
- Department of Microbiology & Immunology, University of Maryland School of Medicine, and Institute of Marine and Environmental Technology, 701 E. Pratt Street, Baltimore, MD, 21202, USA.
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12
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Integrated grazer management mediated by chemicals for sustainable cultivation of algae in open ponds. ALGAL RES 2018. [DOI: 10.1016/j.algal.2018.09.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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13
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Klinger CM, Paoli L, Newby RJ, Wang MYW, Carroll HD, Leblond JD, Howe CJ, Dacks JB, Bowler C, Cahoon AB, Dorrell RG, Richardson E. Plastid Transcript Editing across Dinoflagellate Lineages Shows Lineage-Specific Application but Conserved Trends. Genome Biol Evol 2018; 10:1019-1038. [PMID: 29617800 PMCID: PMC5888634 DOI: 10.1093/gbe/evy057] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2018] [Indexed: 11/24/2022] Open
Abstract
Dinoflagellates are a group of unicellular protists with immense ecological and evolutionary significance and cell biological diversity. Of the photosynthetic dinoflagellates, the majority possess a plastid containing the pigment peridinin, whereas some lineages have replaced this plastid by serial endosymbiosis with plastids of distinct evolutionary affiliations, including a fucoxanthin pigment-containing plastid of haptophyte origin. Previous studies have described the presence of widespread substitutional RNA editing in peridinin and fucoxanthin plastid genes. Because reports of this process have been limited to manual assessment of individual lineages, global trends concerning this RNA editing and its effect on the biological function of the plastid are largely unknown. Using novel bioinformatic methods, we examine the dynamics and evolution of RNA editing over a large multispecies data set of dinoflagellates, including novel sequence data from the peridinin dinoflagellate Pyrocystis lunula and the fucoxanthin dinoflagellate Karenia mikimotoi. We demonstrate that while most individual RNA editing events in dinoflagellate plastids are restricted to single species, global patterns, and functional consequences of editing are broadly conserved. We find that editing is biased toward specific codon positions and regions of genes, and generally corrects otherwise deleterious changes in the genome prior to translation, though this effect is more prevalent in peridinin than fucoxanthin lineages. Our results support a model for promiscuous editing application subsequently shaped by purifying selection, and suggest the presence of an underlying editing mechanism transferred from the peridinin-containing ancestor into fucoxanthin plastids postendosymbiosis, with remarkably conserved functional consequences in the new lineage.
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Affiliation(s)
- Christen M Klinger
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Lucas Paoli
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada.,Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Robert J Newby
- Department of Biology, Middle Tennessee State University
| | - Matthew Yu-Wei Wang
- Center for Computational Science and Department of Computer Science, Columbus State University, Columbus, GA 31907
| | - Hyrum D Carroll
- Center for Computational Science and Department of Computer Science, Columbus State University, Columbus, GA 31907
| | | | | | - Joel B Dacks
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Chris Bowler
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
| | - Aubery Bruce Cahoon
- Department of Natural Sciences, The University of Virginia's College at Wise
| | - Richard G Dorrell
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France
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14
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Roy S, Jagus R, Morse D. Translation and Translational Control in Dinoflagellates. Microorganisms 2018; 6:microorganisms6020030. [PMID: 29642465 PMCID: PMC6027434 DOI: 10.3390/microorganisms6020030] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/03/2018] [Accepted: 04/05/2018] [Indexed: 12/24/2022] Open
Abstract
Dinoflagellates are unicellular protists that feature a multitude of unusual nuclear features, including large genomes, packaging of DNA without histones, and multiple gene copies organized as tandem gene arrays. Furthermore, all dinoflagellate mRNAs experience trans-splicing with a common 22-nucleotide splice leader (SL) sequence. These features challenge some of the concepts and assumptions about the regulation of gene expression derived from work on model eukaryotes such as yeasts and mammals. Translational control in the dinoflagellates, based on extensive study of circadian bioluminescence and by more recent microarray and transcriptome analyses, is now understood to be a crucial element in regulating gene expression. A picture of the translation machinery of dinoflagellates is emerging from the recent availability of transcriptomes of multiple dinoflagellate species and the first complete genome sequences. The components comprising the translational control toolkit of dinoflagellates are beginning to take shape and are outlined here.
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Affiliation(s)
- Sougata Roy
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, 4101 Sherbrooke East, Montréal, QC H1X 2B2, Canada.
| | - Rosemary Jagus
- Institute of Marine & Environmental Technology, University of Maryland Center for Environmental Science701 E. Pratt St., Baltimore, MD 21202, USA.
| | - David Morse
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, 4101 Sherbrooke East, Montréal, QC H1X 2B2, Canada.
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15
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Lau YT, Gambino L, Santos B, Pales Espinosa E, Allam B. Transepithelial migration of mucosal hemocytes in Crassostrea virginica and potential role in Perkinsus marinus pathogenesis. J Invertebr Pathol 2018. [PMID: 29518429 DOI: 10.1016/j.jip.2018.03.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
We have recently described the presence of hemocytes associated with mucus covering the pallial organs (mantle, gills, and body wall) 3 of the eastern oyster Crassostrea virginica. These hemocytes, hereby designated "pallial hemocytes" share common general characteristics with circulating hemocytes but also display significant differences particularly in their cell surface epitopes. The specific location of pallial hemocytes as peripheral cells exposed directly to the marine environment confers them a putative sentinel role. The purpose of this study was to gain a better understanding of the source of these pallial hemocytes by evaluating possible exchanges between circulatory and pallial hemocyte populations and whether these exchanges are regulated by pathogen exposure. Bi-directional transepithelial migrations of hemocytes between pallial surfaces and the circulatory system were monitored using standard cell tracking approaches after staining with the vital fluorescent dye carboxyfluorescein diacetate succinimidyl ester (CFSE) in conjunction with fluorescent microscopy and flow cytometry. Results showed bi-directional migration of hemocytes between both compartments and suggest that hemocyte migration from the pallial mucus layer to the circulatory system may occur at a greater rate compared to migration from the circulatory system to the pallial mucus layer, further supporting the role of pallial hemocytes as sentinel cells. Subsequently, the effect of the obligate parasite Perkinsus marinus and the opportunistic pathogen Vibrio alginolyticus on transepithelial migration of oyster hemocytes was investigated. Results showed an increase in hemocyte migration in response to P. marinus exposure. Furthermore, P. marinus cells were acquired by pallial hemocytes before being visible in underlying tissues and the circulatory system suggesting that this parasite could use pallial hemocytes as a vehicle facilitating its access to oyster tissues. These results are discussed in light of new evidence highlighting the role of oyster pallial organs as a portal for the initiation of P. marinus infections in oysters.
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Affiliation(s)
- Yuk-Ting Lau
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Laura Gambino
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | - Bianca Santos
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA
| | | | - Bassem Allam
- School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794, USA.
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16
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Cold ER, Vasta GR, Robledo JAF. Transient Expression of Plasmodium berghei MSP8 and HAP2 in the Marine Protozoan Parasite Perkinsus marinus. J Parasitol 2016; 103:118-122. [PMID: 27723436 DOI: 10.1645/16-88] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Perkinsus marinus is a protozoan parasite of molluscs that can be propagated in vitro in a defined culture medium, in the absence of host cells. We previously reported that P. marinus trophozoites can be transfected with high efficiency by electroporation using a plasmid based on MOE, a highly expressed gene, and proposed its potential use as a "pseudoparasite." This is a novel gene expression platform for parasites of medical relevance for which the choice of the surrogate organism is based on phylogenetic affinity to the parasite of interest, while taking advantage of the whole engineered surrogate organism as a vaccination adjuvant. Here we improved the original transfection plasmid by incorporating a multicloning site, an enterokinase recognition sequence upstream of GFP, and a His-tag and demonstrate its potential suitability for the heterologous expression of Plasmodium sp. genes relevant to the development of anti-malarial vaccines. Plasmodium berghei HAP2 and MSP8, currently considered candidate genes for a malaria vaccine, were cloned into p[MOE]:GFP, and the constructs were used to transfect P. marinus trophozoites. Within 48 hr of transfection we observed fluorescent cells indicating that the P. berghei genes fused to GFP were expressed. The expression appeared to be transient for both P. berghei genes, as florescence of the transfectants diminished gradually over time. Although this heterologous expression system will require optimization for integration and constitutive expression of Plasmodium genes, our results represent attainment of proof for the "pseudoparasite" concept we previously proposed, as we show that the engineered P. marinus system has the potential to become a surrogate system suitable for expression of Plasmodium spp. genes of interest, which could eventually be used as a malaria vaccine delivery platform. The aim of the present study was to test the ability of marine protozoan parasite P. marinus to express genes of P. berghei .
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Affiliation(s)
- Emma R Cold
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine 04544
| | - Gerardo R Vasta
- Bigelow Laboratory for Ocean Sciences, East Boothbay, Maine 04544
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17
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Schrével J, Valigurová A, Prensier G, Chambouvet A, Florent I, Guillou L. Ultrastructure of Selenidium pendula, the Type Species of Archigregarines, and Phylogenetic Relations to Other Marine Apicomplexa. Protist 2016; 167:339-368. [PMID: 27423403 DOI: 10.1016/j.protis.2016.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/30/2016] [Accepted: 06/12/2016] [Indexed: 01/16/2023]
Abstract
Archigregarines, an early branching lineage within Apicomplexa, are a poorly-known group of invertebrate parasites. By their phylogenetic position, archigregarines are an important lineage to understand the functional transition that occurred between free-living flagellated predators to obligatory parasites in Apicomplexa. In this study, we provide new ultrastructural data and phylogenies based on SSU rDNA sequences using the type species of archigregarines, the Selenidiidae Selenidium pendulaGiard, 1884. We describe for the first time the syzygy and early gamogony at the ultrastructural level, revealing a characteristic nuclear multiplication with centrocones, cryptomitosis, filamentous network of chromatin, a cyst wall secretion and a 9+0 flagellar axoneme of the male gamete. S. pendula belongs to a monophyletic lineage that includes several other related species, all infecting Sedentaria Polychaeta (Spionidae, Sabellaridae, Sabellidae and Cirratulidae). All of these Selenidium species exhibit similar biological characters: a cell cortex with the plasma membrane - inner membrane complex - subpellicular microtubule sets, an apical complex with the conoid, numerous rhoptries and micronemes, a myzocytosis with large food vacuoles, a nuclear multiplication during syzygy and young gamonts. Two other distantly related Selenidium-like lineages infect Terebellidae and Sipunculida, underlying the ability of archigregarines to parasite a wide range of marine hosts.
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Affiliation(s)
- Joseph Schrével
- Unité Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR 7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005 Paris, France.
| | - Andrea Valigurová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Gérard Prensier
- Cell Biology and Electron Microscopy Laboratory, François Rabelais University, 10 Boulevard Tonnellé, BP 3223, 37032 Tours Cedex, France
| | - Aurélie Chambouvet
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Technopole Brest Iroise, 29280 Plouzané, France
| | - Isabelle Florent
- Unité Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR 7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005 Paris, France
| | - Laure Guillou
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, CS90074, 29688 Roscoff cedex, France
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18
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Abstract
In many species of phytoplankton, simple photoreceptors monitor ambient lighting. Photoreceptors provide a number of selective advantages including the ability to assess the time of day for circadian rhythms, seasonal changes, and the detection of excessive light intensities and harmful UV light. Photoreceptors also serve as depth gauges in the water column for behaviors such as diurnal vertical migration. Photoreceptors can be organized together with screening pigment into visible eyespots. In a wide variety of motile phytoplankton, including Chlamydomonas, Volvox, Euglena, and Kryptoperidinium, eyespots are light-sensitive organelles residing within the cell. Eyespots are composed of photoreceptor proteins and typically red to orange carotenoid screening pigments. This association of photosensory pigment with screening pigment allows for detection of light directionality, needed for light-guided behaviors such as positive and negative phototaxis. In Chlamydomonas, the eyespot is located in the chloroplast and Chlamydomonas expresses a number of photosensory pigments including the microbial channelrhodopsins (ChR1 and ChR2). Dinoflagellates are unicellular protists that are ecologically important constituents of the phytoplankton. They display a great deal of diversity in morphology, nutritional modes and symbioses, and can be photosynthetic or heterotrophic, feeding on smaller phytoplankton. Dinoflagellates, such as Kryptoperidinium foliaceum, have eyespots that are used for light-mediated tasks including phototaxis. Dinoflagellates belonging to the family Warnowiaceae have a more elaborate eye. Their eye-organelle, called an ocelloid, is a large, elaborate structure consisting of a focusing lens, highly ordered retinal membranes, and a shield of dark pigment. This complex eye-organelle is similar to multicellular camera eyes, such as our own. Unraveling the molecular makeup, structure and function of dinoflagellate eyes, as well as light-guided behaviors in phytoplankton can inform us about the selective forces that drove evolution in the important steps from light detection to vision. We show here that the evolution from simple photoreception to vision seems to have independently followed identical paths and principles in phytoplankton and animals, significantly strengthening our understanding of this important biological process.
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Affiliation(s)
- Nansi Jo Colley
- *Department of Ophthalmology and Visual Sciences, Department of Genetics, McPherson Eye Research Institute, University of Wisconsin, Madison, 53792 WI, USA
| | - Dan-Eric Nilsson
- Lund Vision Group, Department of Biology, University of Lund, Lund, SE-221 00, Sweden
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19
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Bentlage B, Rogers TS, Bachvaroff TR, Delwiche CF. Complex Ancestries of Isoprenoid Synthesis in Dinoflagellates. J Eukaryot Microbiol 2015; 63:123-37. [PMID: 26291956 DOI: 10.1111/jeu.12261] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 08/12/2015] [Accepted: 08/12/2015] [Indexed: 11/29/2022]
Abstract
Isoprenoid metabolism occupies a central position in the anabolic metabolism of all living cells. In plastid-bearing organisms, two pathways may be present for de novo isoprenoid synthesis, the cytosolic mevalonate pathway (MVA) and nuclear-encoded, plastid-targeted nonmevalonate pathway (DOXP). Using transcriptomic data we find that dinoflagellates apparently make exclusive use of the DOXP pathway. Using phylogenetic analyses of all DOXP genes we inferred the evolutionary origins of DOXP genes in dinoflagellates. Plastid replacements led to a DOXP pathway of multiple evolutionary origins. Dinoflagellates commonly referred to as dinotoms due to their relatively recent acquisition of a diatom plastid, express two completely redundant DOXP pathways. Dinoflagellates with a tertiary plastid of haptophyte origin, by contrast, express a hybrid pathway of dual evolutionary origin. Here, changes in the targeting motif of signal/transit peptide likely allow for targeting the new plastid by the proteins of core isoprenoid metabolism proteins. Parasitic dinoflagellates of the Amoebophyra species complex appear to have lost the DOXP pathway, suggesting that they may rely on their host for sterol synthesis.
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Affiliation(s)
- Bastian Bentlage
- CMNS-Cell Biology and Molecular Genetics, University of Maryland, 2107 Bioscience Research Building, College Park, Maryland, 20742
| | - Travis S Rogers
- CMNS-Cell Biology and Molecular Genetics, University of Maryland, 2107 Bioscience Research Building, College Park, Maryland, 20742
| | - Tsvetan R Bachvaroff
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, 701 E Pratt St., Baltimore, Maryland, 21202
| | - Charles F Delwiche
- CMNS-Cell Biology and Molecular Genetics, University of Maryland, 2107 Bioscience Research Building, College Park, Maryland, 20742.,Maryland Agricultural Experiment Station, AGNR, University of Maryland, College Park, Maryland, 20742
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20
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Fernández-Boo S, Villalba A, Cao A. Cell proteome variability of protistan mollusc parasite Perkinsus olseni among regions of the Spanish coast. DISEASES OF AQUATIC ORGANISMS 2015; 113:245-256. [PMID: 25850402 DOI: 10.3354/dao02835] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We evaluated the proteome variability of in vitro-cultured Perkinsus olseni cells deriving from 4 regions of the Spanish coast: the rías of Arousa and Pontevedra (Galicia, NW Spain), Carreras River in Huelva (Andalusia, SW Spain) and Delta de l'Ebre (Catalonia, NE Spain). P. olseni in vitro clonal cultures were produced starting from parasite isolates from 4 individual clams from each region. Those clonal cultures were used to extract cell proteins, which were separated by 2-dimensional (2D) electrophoresis. Qualitative comparison of P. olseni protein expression profiles among regions was performed with PD Quest software. Around 700 protein spots from parasites derived from each region were considered, from which 141 spots were shared by all the regions. Various spots were found to be exclusive to each region. Higher similarity was found among the proteomes of P. olseni from the Atlantic regions than between those from the Mediterranean and the Atlantic. A total of 54 spots were excised from the gels and sequenced. Nineteen proteins were annotated after searching in databases, 13 being shared by all the regions and 6 exclusive to 1 region. Most of the identified proteins were involved in glycolysis, oxidation/reduction, metabolism and response to stress. No direct evidence of P. olseni variability associated with virulence was found within the protein set analysed, although the differences in metabolic adaptation and stress response could be connected to pathogenicity.
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Affiliation(s)
- Sergio Fernández-Boo
- Centro de Investigacións Mariñas, Consellería do Medio Rural e do Mar, Xunta de Galicia, 36620 Vilanova de Arousa, Spain
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21
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Jones GD, Williams EP, Place AR, Jagus R, Bachvaroff TR. The alveolate translation initiation factor 4E family reveals a custom toolkit for translational control in core dinoflagellates. BMC Evol Biol 2015; 15:14. [PMID: 25886308 PMCID: PMC4330643 DOI: 10.1186/s12862-015-0301-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 01/29/2015] [Indexed: 01/27/2023] Open
Abstract
Background Dinoflagellates are eukaryotes with unusual cell biology and appear to rely on translational rather than transcriptional control of gene expression. The eukaryotic translation initiation factor 4E (eIF4E) plays an important role in regulating gene expression because eIF4E binding to the mRNA cap is a control point for translation. eIF4E is part of an extended, eukaryote-specific family with different members having specific functions, based on studies of model organisms. Dinoflagellate eIF4E diversity could provide a mechanism for dinoflagellates to regulate gene expression in a post-transcriptional manner. Accordingly, eIF4E family members from eleven core dinoflagellate transcriptomes were surveyed to determine the diversity and phylogeny of the eIF4E family in dinoflagellates and related lineages including apicomplexans, ciliates and heterokonts. Results The survey uncovered eight to fifteen (on average eleven) different eIF4E family members in each core dinoflagellate species. The eIF4E family members from heterokonts and dinoflagellates segregated into three clades, suggesting at least three eIF4E cognates were present in their common ancestor. However, these three clades are distinct from the three previously described eIF4E classes, reflecting diverse approaches to a central eukaryotic function. Heterokonts contain four clades, ciliates two and apicomplexans only a single recognizable eIF4E clade. In the core dinoflagellates, the three clades were further divided into nine sub-clades based on the phylogenetic analysis and species representation. Six of the sub-clades included at least one member from all eleven core dinoflagellate species, suggesting duplication in their shared ancestor. Conservation within sub-clades varied, suggesting different selection pressures. Conclusions Phylogenetic analysis of eIF4E in core dinoflagellates revealed complex layering of duplication and conservation when compared to other eukaryotes. Our results suggest that the diverse eIF4E family in core dinoflagellates may provide a toolkit to enable selective translation as a strategy for controlling gene expression in these enigmatic eukaryotes. Electronic supplementary material The online version of this article (doi:10.1186/s12862-015-0301-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Grant D Jones
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, USA. .,University of Maryland, Baltimore, Graduate School, Baltimore, USA.
| | - Ernest P Williams
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, USA.
| | - Allen R Place
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, USA.
| | - Rosemary Jagus
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, USA.
| | - Tsvetan R Bachvaroff
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, USA.
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22
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Valencia JM, Bassitta M, Picornell A, Ramon C, Castro JA. New data on Perkinsus mediterraneus in the Balearic Archipelago: locations and affected species. DISEASES OF AQUATIC ORGANISMS 2014; 112:69-82. [PMID: 25392044 DOI: 10.3354/dao02795] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Perkinsus mediterraneus, a protozoan parasite that can cause perkinsosis (marine mollusc disease), was first detected in oysters Ostrea edulis from Mahon (Minorca, Balearic Islands, Spain) in 2004. Several years later it was also found in Andratx Harbour (Majorca, Balearic Islands) and in the Gulf of Manfredonia (Adriatic coast of Italy) in oyster populations. Since 2007, Perkinsus surveys have been conducted in different localities and shellfish species in the Balearic Archipelago. In the present work, we found P. mediterraneus in the Balearic Islands infecting oyster and other shellfish species. We describe infection with P. mediterraneus for the first time in Arca noae and Mimachlamys varia. The detection was carried out using Ray's fluid thioglycolate medium (RFTM), histology and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodologies. The internal transcribed spacer (ITS) region (including ITS1, 5.8S and ITS2) of P. mediterraneus ribosomal DNA was sequenced from infected bivalve gills (or from the body in Chamelea gallina) from Balearic Archipelago localities. Twelve haplotypes with a strong genetic similarity between them (97-100%) were observed in our samples. These data were completed with 12 more haplotypes from GenBank sequences. The phylogenetic relationship between Balearic P. mediterraneus haplotypes found in this study, those previously obtained in Mahon Harbour, and the Perkinsus spp. sequences available in GenBank clearly grouped the different Perkinsus spp. in distinct clades supported by strong bootstrap values. Moreover, these analyses detected different P. mediterraneus groups in O. edulis from Minorca Island. No abnormal mortalities or decline in populations were detected during the survey, except for C. gallina, which is also affected by Marteilia refringens.
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Affiliation(s)
- J M Valencia
- Laboratori d'Investigacions Marines i Aqüicultura (LIMIA), Av. Ingeniero Gabriel Roca, 69, Port d'Andratx, Illes Balears, 07158, Spain
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23
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Genomic insights into processes driving the infection of Alexandrium tamarense by the Parasitoid Amoebophrya sp. EUKARYOTIC CELL 2014; 13:1439-49. [PMID: 25239978 DOI: 10.1128/ec.00139-14] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The regulatory circuits during infection of dinoflagellates by their parasites are largely unknown on the molecular level. Here we provide molecular insights into these infection dynamics. Alexandrium tamarense is one of the most prominent harmful algal bloom dinoflagellates. Its pathogen, the dinoflagellate parasitoid Amoebophrya sp., has been observed to infect and control the blooms of this species. We generated a data set of transcripts from three time points (0, 6, and 96 h) during the infection of this parasite-host system. Assembly of all transcript data from the parasitoid (>900,000 reads/313 Mbp with 454/Roche next-generation sequencing [NGS]) yielded 14,455 contigs, to which we mapped the raw transcript reads of each time point of the infection cycle. We show that particular surface lectins are expressed at the beginning of the infection cycle which likely mediate the attachment to the host cell. In a later phase, signal transduction-related genes together with transmembrane transport and cytoskeleton proteins point to a high integration of processes involved in host recognition, adhesion, and invasion. At the final maturation stage, cell division- and proliferation-related genes were highly expressed, reflecting the fast cell growth and nuclear division of the parasitoid. Our molecular insights into dinoflagellate parasitoid interactions point to general mechanisms also known from other eukaryotic parasites, especially from the Alveolata. These similarities indicate the presence of fundamental processes of parasitoid infection that have remained stable throughout evolution within different phyla.
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24
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Tikhonenkov DV, Janouškovec J, Mylnikov AP, Mikhailov KV, Simdyanov TG, Aleoshin VV, Keeling PJ. Description of Colponema vietnamica sp.n. and Acavomonas peruviana n. gen. n. sp., two new alveolate phyla (Colponemidia nom. nov. and Acavomonidia nom. nov.) and their contributions to reconstructing the ancestral state of alveolates and eukaryotes. PLoS One 2014; 9:e95467. [PMID: 24740116 PMCID: PMC3989336 DOI: 10.1371/journal.pone.0095467] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Accepted: 03/27/2014] [Indexed: 11/21/2022] Open
Abstract
The evolutionary and ecological importance of predatory flagellates are too often overlooked. This is not only a gap in our understanding of microbial diversity, but also impacts how we interpret their better-studied relatives. A prime example of these problems is found in the alveolates. All well-studied species belong to three large clades (apicomplexans, dinoflagellates, and ciliates), but the predatory colponemid flagellates are also alveolates that are rare in nature and seldom cultured, but potentially important to our understanding of alveolate evolution. Recently we reported the first cultivation and molecular analysis of several colponemid-like organisms representing two novel clades in molecular trees. Here we provide ultrastructural analysis and formal species descriptions for both new species, Colponema vietnamica n. sp. and Acavomonas peruviana n. gen. n. sp. Morphological and feeding characteristics concur with molecular data that both species are distinct members of alveolates, with Acavomonas lacking the longitudinal phagocytotic groove, a defining feature of Colponema. Based on ultrastructure and molecular phylogenies, which both provide concrete rationale for a taxonomic reclassification of Alveolata, we establish the new phyla Colponemidia nom. nov. for the genus Colponema and its close relatives, and Acavomonidia nom. nov. for the genus Acavomonas and its close relatives. The morphological data presented here suggests that colponemids are central to our understanding of early alveolate evolution, and suggest they also retain features of the common ancestor of all eukaryotes.
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Affiliation(s)
- Denis V. Tikhonenkov
- Canadian Institute for Advanced Research, Botany Department, University of British Columbia, Vancouver, British Columbia, Canada
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Provence, Russia
| | - Jan Janouškovec
- Canadian Institute for Advanced Research, Botany Department, University of British Columbia, Vancouver, British Columbia, Canada
| | - Alexander P. Mylnikov
- Institute for Biology of Inland Waters, Russian Academy of Sciences, Borok, Yaroslavl Provence, Russia
| | - Kirill V. Mikhailov
- Belozersky Institute for Physicochemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | - Vladimir V. Aleoshin
- Belozersky Institute for Physicochemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Patrick J. Keeling
- Canadian Institute for Advanced Research, Botany Department, University of British Columbia, Vancouver, British Columbia, Canada
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Pallial mucus of the oyster Crassostrea virginica regulates the expression of putative virulence genes of its pathogen Perkinsus marinus. Int J Parasitol 2014; 44:305-17. [DOI: 10.1016/j.ijpara.2014.01.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2013] [Revised: 01/10/2014] [Accepted: 01/15/2014] [Indexed: 01/11/2023]
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Lee R, Lai H, Malik SB, Saldarriaga JF, Keeling PJ, Slamovits CH. Analysis of EST data of the marine protist Oxyrrhis marina, an emerging model for alveolate biology and evolution. BMC Genomics 2014; 15:122. [PMID: 24512041 PMCID: PMC3942190 DOI: 10.1186/1471-2164-15-122] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2013] [Accepted: 02/06/2014] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The alveolates include a large number of important lineages of protists and algae, among which are three major eukaryotic groups: ciliates, apicomplexans and dinoflagellates. Collectively alveolates are present in virtually every environment and include a vast diversity of cell shapes, molecular and cellular features and feeding modes including lifestyles such as phototrophy, phagotrophy/predation and intracellular parasitism, in addition to a variety of symbiotic associations. Oxyrrhis marina is a well-known model for heterotrophic protist biology, and is now emerging as a useful organism to explore the many changes that occurred during the origin and diversification of dinoflagellates by virtue of its phylogenetic position at the base of the dinoflagellate tree. RESULTS We have generated and analysed expressed sequence tag (EST) sequences from the alveolate Oxyrrhis marina in order to shed light on the evolution of a number of dinoflagellate characteristics, especially regarding the emergence of highly unusual genomic features. We found that O. marina harbours extensive gene redundancy, indicating high rates of gene duplication and transcription from multiple genomic loci. In addition, we observed a correlation between expression level and copy number in several genes, suggesting that copy number may contribute to determining transcript levels for some genes. Finally, we analyze the genes and predicted products of the recently discovered Dinoflagellate Viral Nuclear Protein, and several cases of horizontally acquired genes. CONCLUSION The dataset presented here has proven very valuable for studying this important group of protists. Our analysis indicates that gene redundancy is a pervasive feature of dinoflagellate genomes, thus the mechanisms involved in its generation must have arisen early in the evolution of the group.
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Affiliation(s)
- Renny Lee
- Department of Biochemistry and Molecular Biology, Dalhousie University, B3H4R2 Halifax, NS, Canada
| | - Hugo Lai
- Department of Biochemistry and Molecular Biology, Dalhousie University, B3H4R2 Halifax, NS, Canada
| | - Shehre Banoo Malik
- Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Alberta, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, B3H4R2 Halifax, NS, Canada
| | - Juan F Saldarriaga
- Botany Department, University of British Columbia, V6T1Z4 Vancouver, BS, Canada
| | - Patrick J Keeling
- Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Alberta, Canada
- Botany Department, University of British Columbia, V6T1Z4 Vancouver, BS, Canada
| | - Claudio H Slamovits
- Canadian Institute for Advanced Research, Program in Integrated Microbial Biodiversity, Alberta, Canada
- Department of Biochemistry and Molecular Biology, Dalhousie University, B3H4R2 Halifax, NS, Canada
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Humanized HLA-DR4 mice fed with the protozoan pathogen of oysters Perkinsus marinus (Dermo) do not develop noticeable pathology but elicit systemic immunity. PLoS One 2014; 9:e87435. [PMID: 24498105 PMCID: PMC3909113 DOI: 10.1371/journal.pone.0087435] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 12/23/2013] [Indexed: 12/02/2022] Open
Abstract
Perkinsus marinus (Phylum Perkinsozoa) is a marine protozoan parasite responsible for “Dermo” disease in oysters, which has caused extensive damage to the shellfish industry and estuarine environment. The infection prevalence has been estimated in some areas to be as high as 100%, often causing death of infected oysters within 1–2 years post-infection. Human consumption of the parasites via infected oysters is thus likely to occur, but to our knowledge the effect of oral consumption of P. marinus has not been investigated in humans or other mammals. To address the question we used humanized mice expressing HLA-DR4 molecules and lacking expression of mouse MHC-class II molecules (DR4.EA0) in such a way that CD4 T cell responses are solely restricted by the human HLA-DR4 molecule. The DR4.EA0 mice did not develop diarrhea or any detectable pathology in the gastrointestinal tract or lungs following single or repeated feedings with live P. marinus parasites. Furthermore, lymphocyte populations in the gut associated lymphoid tissue and spleen were unaltered in the parasite-fed mice ruling out local or systemic inflammation. Notably, naïve DR4.EA0 mice had antibodies (IgM and IgG) reacting against P. marinus parasites whereas parasite specific T cell responses were undetectable. Feeding with P. marinus boosted the antibody responses and stimulated specific cellular (IFNγ) immunity to the oyster parasite. Our data indicate the ability of P. marinus parasites to induce systemic immunity in DR4.EA0 mice without causing noticeable pathology, and support rationale grounds for using genetically engineered P. marinus as a new oral vaccine platform to induce systemic immunity against infectious agents.
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Lepelletier F, Karpov SA, Le Panse S, Bigeard E, Skovgaard A, Jeanthon C, Guillou L. Parvilucifera rostrata sp. nov. (Perkinsozoa), a Novel Parasitoid that Infects Planktonic Dinoflagellates. Protist 2014; 165:31-49. [DOI: 10.1016/j.protis.2013.09.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 09/04/2013] [Accepted: 09/15/2013] [Indexed: 10/26/2022]
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Biology of the Marine Heterotrophic Dinoflagellate Oxyrrhis marina: Current Status and Future Directions. Microorganisms 2013; 1:33-57. [PMID: 27694763 PMCID: PMC5029500 DOI: 10.3390/microorganisms1010033] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/02/2013] [Accepted: 10/08/2013] [Indexed: 11/17/2022] Open
Abstract
Heterotrophic dinoflagellates are prevalent protists in marine environments, which play an important role in the carbon cycling and energy flow in the marine planktonic community. Oxyrrhismarina (Dinophyceae), a widespread heterotrophic dinoflagellate, is a model species used for a broad range of ecological, biogeographic, and evolutionary studies. Despite the increasing research effort on this species, there lacks a synthesis of the existing data and a coherent picture of this organism. Here we reviewed the literature to provide an overview of what is known regarding the biology of O. marina, and identify areas where further studies are needed. As an early branch of the dinoflagellate lineage, O. marina shares similarity with typical dinoflagellates in permanent condensed chromosomes, less abundant nucleosome proteins compared to other eukaryotes, multiple gene copies, the occurrence of trans-splicing in nucleus-encoded mRNAs, highly fragmented mitochondrial genome, and disuse of ATG as a start codon for mitochondrial genes. On the other hand, O. marina also exhibits some distinct cytological features (e.g., different flagellar structure, absence of girdle and sulcus or pustules, use of intranuclear spindle in mitosis, presence of nuclear plaque, and absence of birefringent periodic banded chromosomal structure) and genetic features (e.g., a single histone-like DNA-associated protein, cob-cox3 gene fusion, 5' oligo-U cap in the mitochondrial transcripts of protein-coding genes, the absence of mRNA editing, the presence of stop codon in the fused cob-cox3 mRNA produced by post-transcriptional oligoadenylation, and vestigial plastid genes). The best-studied biology of this dinoflagellate is probably the prey and predators types, which include a wide range of organisms. On the other hand, the abundance of this species in the natural waters and its controlling factors, genome organization and gene expression regulation that underlie the unusual cytological and ecological characteristics are among the areas that urgently need study.
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Bachvaroff TR, Gornik SG, Concepcion GT, Waller RF, Mendez GS, Lippmeier JC, Delwiche CF. Dinoflagellate phylogeny revisited: using ribosomal proteins to resolve deep branching dinoflagellate clades. Mol Phylogenet Evol 2013; 70:314-22. [PMID: 24135237 DOI: 10.1016/j.ympev.2013.10.007] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 09/24/2013] [Accepted: 10/07/2013] [Indexed: 10/26/2022]
Abstract
The alveolates are composed of three major lineages, the ciliates, dinoflagellates, and apicomplexans. Together these 'protist' taxa play key roles in primary production and ecology, as well as in illness of humans and other animals. The interface between the dinoflagellate and apicomplexan clades has been an area of recent discovery, blurring the distinction between these two clades. Moreover, phylogenetic analysis has yet to determine the position of basal dinoflagellate clades hence the deepest branches of the dinoflagellate tree currently remain unresolved. Large-scale mRNA sequencing was applied to 11 species of dinoflagellates, including strains of the syndinean genera Hematodinium and Amoebophrya, parasites of crustaceans and dinoflagellates, respectively, to optimize and update the dinoflagellate tree. From the transcriptome-scale data a total of 73 ribosomal protein-coding genes were selected for phylogeny. After individual gene orthology assessment, the genes were concatenated into a >15,000 amino acid alignment with 76 taxa from dinoflagellates, apicomplexans, ciliates, and the outgroup heterokonts. Overall the tree was well resolved and supported, when the data was subsampled with gblocks or constraint trees were tested with the approximately unbiased test. The deepest branches of the dinoflagellate tree can now be resolved with strong support, and provides a clearer view of the evolution of the distinctive traits of dinoflagellates.
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Affiliation(s)
- Tsvetan R Bachvaroff
- Smithsonian Environmental Research Center, 647 Contees Wharf Rd., Edgewater, MD 21037, United States.
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31
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Abstract
Dinoflagellates are unique among eukaryotes in their unusual 'dinokaryons' - nuclei that lack bulk histones. A new study finds that acquisition of a novel dinoflagellate chromatin protein was an early step in the transition to a nucleus lacking detectable nucleosomes.
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Affiliation(s)
- Paul B Talbert
- Howard Hughes Medical Institute and Basic Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
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Swart EC, Bracht JR, Magrini V, Minx P, Chen X, Zhou Y, Khurana JS, Goldman AD, Nowacki M, Schotanus K, Jung S, Fulton RS, Ly A, McGrath S, Haub K, Wiggins JL, Storton D, Matese JC, Parsons L, Chang WJ, Bowen MS, Stover NA, Jones TA, Eddy SR, Herrick GA, Doak TG, Wilson RK, Mardis ER, Landweber LF. The Oxytricha trifallax macronuclear genome: a complex eukaryotic genome with 16,000 tiny chromosomes. PLoS Biol 2013; 11:e1001473. [PMID: 23382650 PMCID: PMC3558436 DOI: 10.1371/journal.pbio.1001473] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 12/12/2012] [Indexed: 01/03/2023] Open
Abstract
With more chromosomes than any other sequenced genome, the macronuclear genome of Oxytricha trifallax has a unique and complex architecture, including alternative fragmentation and predominantly single-gene chromosomes. The macronuclear genome of the ciliate Oxytricha trifallax displays an extreme and unique eukaryotic genome architecture with extensive genomic variation. During sexual genome development, the expressed, somatic macronuclear genome is whittled down to the genic portion of a small fraction (∼5%) of its precursor “silent” germline micronuclear genome by a process of “unscrambling” and fragmentation. The tiny macronuclear “nanochromosomes” typically encode single, protein-coding genes (a small portion, 10%, encode 2–8 genes), have minimal noncoding regions, and are differentially amplified to an average of ∼2,000 copies. We report the high-quality genome assembly of ∼16,000 complete nanochromosomes (∼50 Mb haploid genome size) that vary from 469 bp to 66 kb long (mean ∼3.2 kb) and encode ∼18,500 genes. Alternative DNA fragmentation processes ∼10% of the nanochromosomes into multiple isoforms that usually encode complete genes. Nucleotide diversity in the macronucleus is very high (SNP heterozygosity is ∼4.0%), suggesting that Oxytricha trifallax may have one of the largest known effective population sizes of eukaryotes. Comparison to other ciliates with nonscrambled genomes and long macronuclear chromosomes (on the order of 100 kb) suggests several candidate proteins that could be involved in genome rearrangement, including domesticated MULE and IS1595-like DDE transposases. The assembly of the highly fragmented Oxytricha macronuclear genome is the first completed genome with such an unusual architecture. This genome sequence provides tantalizing glimpses into novel molecular biology and evolution. For example, Oxytricha maintains tens of millions of telomeres per cell and has also evolved an intriguing expansion of telomere end-binding proteins. In conjunction with the micronuclear genome in progress, the O. trifallax macronuclear genome will provide an invaluable resource for investigating programmed genome rearrangements, complementing studies of rearrangements arising during evolution and disease. The macronuclear genome of the ciliate Oxytricha trifallax, contained in its somatic nucleus, has a unique genome architecture. Unlike its diploid germline genome, which is transcriptionally inactive during normal cellular growth, the macronuclear genome is fragmented into at least 16,000 tiny (∼3.2 kb mean length) chromosomes, most of which encode single actively transcribed genes and are differentially amplified to a few thousand copies each. The smallest chromosome is just 469 bp, while the largest is 66 kb and encodes a single enormous protein. We found considerable variation in the genome, including frequent alternative fragmentation patterns, generating chromosome isoforms with shared sequence. We also found limited variation in chromosome amplification levels, though insufficient to explain mRNA transcript level variation. Another remarkable feature of Oxytricha's macronuclear genome is its inordinate fondness for telomeres. In conjunction with its possession of tens of millions of chromosome-ending telomeres per macronucleus, we show that Oxytricha has evolved multiple putative telomere-binding proteins. In addition, we identified two new domesticated transposase-like protein classes that we propose may participate in the process of genome rearrangement. The macronuclear genome now provides a crucial resource for ongoing studies of genome rearrangement processes that use Oxytricha as an experimental or comparative model.
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Affiliation(s)
- Estienne C. Swart
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - John R. Bracht
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Vincent Magrini
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Patrick Minx
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Xiao Chen
- Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Yi Zhou
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Jaspreet S. Khurana
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Aaron D. Goldman
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Mariusz Nowacki
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- Institute of Cell Biology, University of Bern, Bern, Switzerland
| | - Klaas Schotanus
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
| | - Seolkyoung Jung
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Robert S. Fulton
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Amy Ly
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Sean McGrath
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Kevin Haub
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Jessica L. Wiggins
- Sequencing Core Facility, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Donna Storton
- Sequencing Core Facility, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - John C. Matese
- Sequencing Core Facility, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Lance Parsons
- Bioinformatics Group, Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, New Jersey, United States of America
| | - Wei-Jen Chang
- Department of Biology, Hamilton College, Clinton, New York, United States of America
| | - Michael S. Bowen
- Biology Department, Bradley University, Peoria, Illinois, United States of America
| | - Nicholas A. Stover
- Biology Department, Bradley University, Peoria, Illinois, United States of America
| | - Thomas A. Jones
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Sean R. Eddy
- Janelia Farm Research Campus, Howard Hughes Medical Institute, Ashburn, Virginia, United States of America
| | - Glenn A. Herrick
- Biology Department, University of Utah, Salt Lake City, Utah, United States of America
| | - Thomas G. Doak
- Department of Biology, University of Indiana, Bloomington, Indiana, United States of America
| | - Richard K. Wilson
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Elaine R. Mardis
- The Genome Institute, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Laura F. Landweber
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey, United States of America
- * E-mail:
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Loss of Nucleosomal DNA Condensation Coincides with Appearance of a Novel Nuclear Protein in Dinoflagellates. Curr Biol 2012; 22:2303-12. [PMID: 23159597 DOI: 10.1016/j.cub.2012.10.036] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 10/18/2012] [Accepted: 10/19/2012] [Indexed: 11/22/2022]
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Orr RJS, Murray SA, Stüken A, Rhodes L, Jakobsen KS. When naked became armored: an eight-gene phylogeny reveals monophyletic origin of theca in dinoflagellates. PLoS One 2012. [PMID: 23185516 PMCID: PMC3501488 DOI: 10.1371/journal.pone.0050004] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The dinoflagellates are a diverse lineage of microbial eukaryotes. Dinoflagellate monophyly and their position within the group Alveolata are well established. However, phylogenetic relationships between dinoflagellate orders remain unresolved. To date, only a limited number of dinoflagellate studies have used a broad taxon sample with more than two concatenated markers. This lack of resolution makes it difficult to determine the evolution of major phenotypic characters such as morphological features or toxin production e.g. saxitoxin. Here we present an improved dinoflagellate phylogeny, based on eight genes, with the broadest taxon sampling to date. Fifty-five sequences for eight phylogenetic markers from nuclear and mitochondrial regions were amplified from 13 species, four orders, and concatenated phylogenetic inferences were conducted with orthologous sequences. Phylogenetic resolution is increased with addition of support for the deepest branches, though can be improved yet further. We show for the first time that the characteristic dinoflagellate thecal plates, cellulosic material that is present within the sub-cuticular alveoli, appears to have had a single origin. In addition, the monophyly of most dinoflagellate orders is confirmed: the Dinophysiales, the Gonyaulacales, the Prorocentrales, the Suessiales, and the Syndiniales. Our improved phylogeny, along with results of PCR to detect the sxtA gene in various lineages, allows us to suggest that this gene was probably acquired separately in Gymnodinium and the common ancestor of Alexandrium and Pyrodinium and subsequently lost in some descendent species of Alexandrium.
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Affiliation(s)
- Russell J. S. Orr
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, Oslo, Norway
| | - Shauna A. Murray
- Ecology and Evolution Research Centre and School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
- Sydney Institute of Marine Sciences, Mosman, New South Wales, Australia
| | - Anke Stüken
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, Oslo, Norway
| | | | - Kjetill S. Jakobsen
- Microbial Evolution Research Group (MERG), Department of Biology, University of Oslo, Oslo, Norway
- Centre for Ecological and Evolutionary Synthesis (CEES), Department of Biology, University of Oslo, Oslo, Norway
- * E-mail:
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Chan CX, Soares MB, Bonaldo MF, Wisecaver JH, Hackett JD, Anderson DM, Erdner DL, Bhattacharya D. ANALYSIS OF ALEXANDRIUM TAMARENSE (DINOPHYCEAE) GENES REVEALS THE COMPLEX EVOLUTIONARY HISTORY OF A MICROBIAL EUKARYOTE(). JOURNAL OF PHYCOLOGY 2012; 48:1130-1142. [PMID: 23066170 PMCID: PMC3466611 DOI: 10.1111/j.1529-8817.2012.01194.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Microbial eukaryotes may extinguish much of their nuclear phylogenetic history due to endosymbiotic/horizontal gene transfer (E/HGT). We studied E/HGT in 32,110 contigs of expressed sequence tags (ESTs) from the dinoflagellate Alexandrium tamarense (Dinophyceae) using a conservative phylogenomic approach. The vast majority of predicted proteins (86.4%) in this alga are novel or dinoflagellate-specific. We searched for putative homologs of these predicted proteins against a taxonomically broadly sampled protein database that includes all currently available data from algae and protists and reconstructed a phylogeny from each of the putative homologous protein sets. Of the 2,523 resulting phylogenies, 14-17% are potentially impacted by E/HGT involving both prokaryote and eukaryote lineages, with 2-4% showing clear evidence of reticulate evolution. The complex evolutionary histories of the remaining proteins, many of which may also have been affected by E/HGT, cannot be interpreted using our approach with currently available gene data. We present empirical evidence of reticulate genome evolution that combined with inadequate or highly complex phylogenetic signal in many proteins may impede genome-wide approaches to infer the tree of microbial eukaryotes.
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Affiliation(s)
- Cheong Xin Chan
- Department of Ecology, Evolution and Natural Resources, and Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA
| | - Marcelo B. Soares
- Northwestern University, Children's Memorial Research Center, Chicago, IL 60614, USA
| | - Maria F. Bonaldo
- Northwestern University, Children's Memorial Research Center, Chicago, IL 60614, USA
| | - Jennifer H. Wisecaver
- Department of Ecology and Evolutionary Biology, The University of Arizona, Tucson, AZ 85721, USA
| | - Jeremiah D. Hackett
- Department of Ecology and Evolutionary Biology, The University of Arizona, Tucson, AZ 85721, USA
| | | | - Deana L. Erdner
- Marine Science Institute, University of Texas, Port Aransas, TX 78373, USA
| | - Debashish Bhattacharya
- Department of Ecology, Evolution and Natural Resources, and Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USA
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Gómez F. A quantitative review of the lifestyle, habitat and trophic diversity of dinoflagellates (Dinoflagellata, Alveolata). SYST BIODIVERS 2012. [DOI: 10.1080/14772000.2012.721021] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Umeda K, Yoshinaga T. Development of real-time PCR assays for discrimination and quantification of two Perkinsus spp. in the Manila clam Ruditapes philippinarum. DISEASES OF AQUATIC ORGANISMS 2012; 99:215-225. [PMID: 22832720 DOI: 10.3354/dao02476] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The Manila clam Ruditapes philippinarum is infected with 2 Perkinsus species, Perkinsus olseni and P. honshuensis, in Japan. The latter was described as a new species in Mie Prefecture, Japan, in 2006. Ray's Fluid Thioglycollate Medium (RFTM) assay has been most commonly used to quantify Perkinsus infection. However, this assay cannot discriminate between species that resemble one another morphologically. We developed real-time PCR assays for the specific quantification of P. olseni and P. honshuensis. DNA was extracted using Chelex resin. Cultured P. olseni and P. honshuensis cells were counted and spiked into uninfected clam gill tissue prior to DNA extraction to generate standard curves, which allowed quantification based on the PCR cycle threshold values. We compared the RFTM assay with both real-time PCR assays by quantifying Perkinsus spp. in gill tissue samples from the same individual clams obtained from various localities in Japan. Infection intensities estimated by both assays were significantly correlated (r2 = 0.70). Our results suggest that the prevalence and infection intensity of P. honshuensis are much lower than for P. olseni in Manila clams.
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Affiliation(s)
- Kousuke Umeda
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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Okamoto N, Horák A, Keeling PJ. Description of two species of early branching dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp. PLoS One 2012; 7:e34900. [PMID: 22719825 PMCID: PMC3377698 DOI: 10.1371/journal.pone.0034900] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2011] [Accepted: 03/06/2012] [Indexed: 11/18/2022] Open
Abstract
In alveolate evolution, dinoflagellates have developed many unique features, including the cell that has epicone and hypocone, the undulating transverse flagellum. However, it remains unclear how these features evolved. The early branching dinoflagellates so far investigated such as Hematodinium, Amoebophrya and Oxyrrhis marina differ in many ways from of core dinoflagellates, or dinokaryotes. Except those handful of well studied taxa, the vast majority of early branching dinoflagellates are known only by environmental sequences, and remain enigmatic. In this study we describe two new species of the early branching dinoflagellates, Psammosa pacifica n. g., n. sp. and P. atlantica n. sp. from marine intertidal sandy beach. Molecular phylogeny of the small subunit (SSU) ribosomal RNA and Hsp90 gene places Psammosa spp. as an early branch among the dinoflagellates. Morphologically (1) they lack the typical dinoflagellate epicone-hypocone structure, and (2) undulation in either flagella. Instead they display a mosaïc of dinokaryotes traits, i.e. (3) presence of bi-partite trychocysts; Oxyrrhis marina-like traits, i.e. (4) presence of flagellar hairs, (5) presence of two-dimensional cobweb scales ornamenting both flagella (6) transversal cell division; a trait shared with some syndineansand Parvilucifera spp. i.e. (7) a nucleus with a conspicuous nucleolus and condensed chromatin distributed beneath the nuclear envelope; as well as Perkinsus marinus -like features i.e. (8) separate ventral grooves where flagella emerge and (9) lacking dinoflagellate-type undulating flagellum. Notably Psammosa retains an apical complex structure, which is shared between perkinsids, colpodellids, chromerids and apicomplexans, but is not found in dinokaryotic dinoflagellates.
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Affiliation(s)
- Noriko Okamoto
- Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada.
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Ghoshroy S, Robertson DL. MOLECULAR EVOLUTION OF GLUTAMINE SYNTHETASE II AND III IN THE CHROMALVEOLATES(1). JOURNAL OF PHYCOLOGY 2012; 48:768-783. [PMID: 27011094 DOI: 10.1111/j.1529-8817.2012.01169.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Glutamine synthetase (GS) is encoded by three distinct gene families (GSI, GSII, and GSIII) that are broadly distributed among the three domains of life. Previous studies established that GSII and GSIII isoenzymes were expressed in diatoms; however, less is known about the distribution and evolution of the gene families in other chromalveolate lineages. Thus, GSII cDNA sequences were isolated from three cryptophytes (Guillardia theta D. R. A. Hill et Wetherbee, Cryptomonas phaseolus Skuja, and Pyrenomonas helgolandii Santore), and GSIII was sequenced from G. theta. Red algal GSII sequences were obtained from Bangia atropurpurea (Mertens ex Roth) C. Agardh; Compsopogon caeruleus (Balbis ex C. Agardh) Mont.; Flintiella sanguinaria F. D. Ott and Porphyridium aerugineum Geitler; Rhodella violacea (Kornmann) Wehrmeyer and Dixoniella grisea (Geitler) J. L. Scott, S. T. Broadwater, B. D. Saunders, J. P. Thomas et P. W. Gabrielson; and Stylonema alsidii (Zanardini) K. M. Drew. In Bayesian inference and maximum-likelihood (ML) phylogenetic analyses, chromalveolate GSII sequences formed a weakly supported clade that nested among sequences from glaucophytes, red algae, green algae, and plants. Red algal GSII sequences formed two distinct clades. The largest clade contained representatives from the Cyanidiophytina and Rhodophytina and grouped with plants and green algae. The smaller clade (C. caeruleus, Porphyra yezoensis, and S. alsidii) nested within the chromalveolates, although its placement was unresolved. Chromalveolate GSIII sequences formed a well-supported clade in Bayesian and ML phylogenies, and mitochondrial transit peptides were identified in many of the sequences. There was strong support for a stramenopile-haptophyte-cryptophyte GSIII clade in which the cryptophyte sequence diverged from the deepest node. Overall, the evolutionary history of the GS gene families within the algae is complex with evidence for the presence of orthologous and paralogous sequences, ancient and recent gene duplications, gene losses and replacements, and the potential for both endosymbiotic and lateral gene transfers.
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Affiliation(s)
- Sohini Ghoshroy
- Biology Department, Clark University, 950, Main Street, Worcester, MA 01610, USA
| | - Deborah L Robertson
- Biology Department, Clark University, 950, Main Street, Worcester, MA 01610, USA
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Roy S, Morse D. A full suite of histone and histone modifying genes are transcribed in the dinoflagellate Lingulodinium. PLoS One 2012; 7:e34340. [PMID: 22496791 PMCID: PMC3319573 DOI: 10.1371/journal.pone.0034340] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Accepted: 03/01/2012] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Dinoflagellates typically lack histones and nucleosomes are not observed in DNA spreads. However, recent studies have shown the presence of core histone mRNA sequences scattered among different dinoflagellate species. To date, the presence of all components required for manufacturing and modifying nucleosomes in a single dinoflagellate species has not been confirmed. METHODOLOGY AND RESULTS Analysis of a Lingulodinium transcriptome obtained by Illumina sequencing of mRNA shows several different copies of each of the four core histones as well as a suite of histone modifying enzymes and histone chaperone proteins. Phylogenetic analysis shows one of each Lingulodinium histone copies belongs to the dinoflagellate clade while the second is more divergent and does not share a common ancestor. All histone mRNAs are in low abundance (roughly 25 times lower than higher plants) and transcript levels do not vary over the cell cycle. We also tested Lingulodinium extracts for histone proteins using immunoblotting and LC-MS/MS, but were unable to confirm histone expression at the protein level. CONCLUSION We show that all core histone sequences are present in the Lingulodinium transcriptome. The conservation of these sequences, even though histone protein accumulation remains below currently detectable levels, strongly suggests dinoflagellates possess histones.
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Affiliation(s)
- Sougata Roy
- Institut de Recherche en Biologie Végétale, Département de Sciences Biologiques, Université de Montréal, Montréal, Québec, Canada
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Malcolm H, April H. The magnesium inhibition and arrested phagosome hypotheses: new perspectives on the evolution and ecology ofSymbiodiniumsymbioses. Biol Rev Camb Philos Soc 2012; 87:804-21. [DOI: 10.1111/j.1469-185x.2012.00223.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Chromosomal localisation of five genes in Perkinsus olseni (Phylum Perkinsozoa). Eur J Protistol 2012; 48:194-8. [PMID: 22342132 DOI: 10.1016/j.ejop.2011.11.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2010] [Revised: 10/29/2011] [Accepted: 11/15/2011] [Indexed: 11/21/2022]
Abstract
The molecular karyotype of Perkinsus olseni, a pathogenic protist that infects the clam Ruditapes decussatus, comprises nine chromosomes, ranging in size from 0.15 Mb to 6.5 Mb, representing a haploid genome of about 28 Mb. In order to establish chromosome specific markers, PCR-amplified DNA sequences belonging to five conserved genes (18S rRNA, actin type I, hsp90, β-tubulin and calmodulin) were hybridised to chromosomal bands separated by pulsed-field gel electrophoresis. Three of those probes (actin type I, hsp90 and calmodulin) hybridised to only one chromosome and the remaining two (18S rRNA and β-tubulin) hybridised to two chromosomes. In the first place, the hybridisation pattern obtained serves to dispel any doubt about the nuclear location of the smallest chromosome observed in the molecular karyotype of Perkinsus olseni. Additionally, it will be a reference for further analysis of karyotype polymorphisms in the genus Perkinsus.
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Jackson CJ, Gornik SG, Waller RF. The mitochondrial genome and transcriptome of the basal dinoflagellate Hematodinium sp.: character evolution within the highly derived mitochondrial genomes of dinoflagellates. Genome Biol Evol 2011; 4:59-72. [PMID: 22113794 PMCID: PMC3268668 DOI: 10.1093/gbe/evr122] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The sister phyla dinoflagellates and apicomplexans inherited a drastically reduced mitochondrial genome (mitochondrial DNA, mtDNA) containing only three protein-coding (cob, cox1, and cox3) genes and two ribosomal RNA (rRNA) genes. In apicomplexans, single copies of these genes are encoded on the smallest known mtDNA chromosome (6 kb). In dinoflagellates, however, the genome has undergone further substantial modifications, including massive genome amplification and recombination resulting in multiple copies of each gene and gene fragments linked in numerous combinations. Furthermore, protein-encoding genes have lost standard stop codons, trans-splicing of messenger RNAs (mRNAs) is required to generate complete cox3 transcripts, and extensive RNA editing recodes most genes. From taxa investigated to date, it is unclear when many of these unusual dinoflagellate mtDNA characters evolved. To address this question, we investigated the mitochondrial genome and transcriptome character states of the deep branching dinoflagellate Hematodinium sp. Genomic data show that like later-branching dinoflagellates Hematodinium sp. also contains an inflated, heavily recombined genome of multicopy genes and gene fragments. Although stop codons are also lacking for cox1 and cob, cox3 still encodes a conventional stop codon. Extensive editing of mRNAs also occurs in Hematodinium sp. The mtDNA of basal dinoflagellate Hematodinium sp. indicates that much of the mtDNA modification in dinoflagellates occurred early in this lineage, including genome amplification and recombination, and decreased use of standard stop codons. Trans-splicing, on the other hand, occurred after Hematodinium sp. diverged. Only RNA editing presents a nonlinear pattern of evolution in dinoflagellates as this process occurs in Hematodinium sp. but is absent in some later-branching taxa indicating that this process was either lost in some lineages or developed more than once during the evolution of the highly unusual dinoflagellate mtDNA.
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Affiliation(s)
- C J Jackson
- School of Botany, University of Melbourne, Australia
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Lowe CD, Mello LV, Samatar N, Martin LE, Montagnes DJS, Watts PC. The transcriptome of the novel dinoflagellate Oxyrrhis marina (Alveolata: Dinophyceae): response to salinity examined by 454 sequencing. BMC Genomics 2011; 12:519. [PMID: 22014029 PMCID: PMC3209475 DOI: 10.1186/1471-2164-12-519] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Accepted: 10/20/2011] [Indexed: 11/30/2022] Open
Abstract
Background The heterotrophic dinoflagellate Oxyrrhis marina is increasingly studied in experimental, ecological and evolutionary contexts. Its basal phylogenetic position within the dinoflagellates make O. marina useful for understanding the origin of numerous unusual features of the dinoflagellate lineage; its broad distribution has lent O. marina to the study of protist biogeography; and nutritive flexibility and eurytopy have made it a common lab rat for the investigation of physiological responses of marine heterotrophic flagellates. Nevertheless, genome-scale resources for O. marina are scarce. Here we present a 454-based transcriptome survey for this organism. In addition, we assess sequence read abundance, as a proxy for gene expression, in response to salinity, an environmental factor potentially important in determining O. marina spatial distributions. Results Sequencing generated ~57 Mbp of data which assembled into 7, 398 contigs. Approximately 24% of contigs were nominally identified by BLAST. A further clustering of contigs (at ≥ 90% identity) revealed 164 transcript variant clusters, the largest of which (Phosphoribosylaminoimidazole-succinocarboxamide synthase) was composed of 28 variants displaying predominately synonymous variation. In a genomic context, a sample of 5 different genes were demonstrated to occur as tandem repeats, separated by short (~200-340 bp) inter-genic regions. For HSP90 several intergenic variants were detected suggesting a potentially complex genomic arrangement. In response to salinity, analysis of 454 read abundance highlighted 9 and 20 genes over or under expressed at 50 PSU, respectively. However, 454 read abundance and subsequent qPCR validation did not correlate well - suggesting that measures of gene expression via ad hoc analysis of sequence read abundance require careful interpretation. Conclusion Here we indicate that tandem gene arrangements and the occurrence of multiple transcribed gene variants are common and indicate potentially complex genomic arrangements in O. marina. Comparison of the reported data set with existing O. marina and other dinoflagellates ESTs indicates little sequence overlap likely as a result of the relatively limited extent of genome scale sequence data currently available for the dinoflagellates. This is one of the first 454-based transcriptome surveys of an ancestral dinoflagellate taxon and will undoubtedly prove useful for future comparative studies aimed at reconstructing the origin of novel features of the dinoflagellates.
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Affiliation(s)
- Chris D Lowe
- Department of Evolution, Ecology, and Behaviour, Institute of Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
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Affiliation(s)
| | - Jeremiah D. Hackett
- Ecology and Evolutionary Biology Department, University of Arizona, Tucson, Arizona 85721;
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Fernández Robledo JA, Caler E, Matsuzaki M, Keeling PJ, Shanmugam D, Roos DS, Vasta GR. The search for the missing link: a relic plastid in Perkinsus? Int J Parasitol 2011; 41:1217-29. [PMID: 21889509 DOI: 10.1016/j.ijpara.2011.07.008] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 07/27/2011] [Accepted: 07/28/2011] [Indexed: 12/11/2022]
Abstract
Perkinsus marinus (Phylum Perkinsozoa) is a protozoan parasite that has devastated natural and farmed oyster populations in the USA, significantly affecting the shellfish industry and the estuarine environment. The other two genera in the phylum, Parvilucifera and Rastrimonas, are parasites of microeukaryotes. The Perkinsozoa occupies a key position at the base of the dinoflagellate branch, close to its divergence from the Apicomplexa, a clade that includes parasitic protista, many harbouring a relic plastid. Thus, as a taxon that has also evolved toward parasitism, the Perkinsozoa has attracted the attention of biologists interested in the evolution of this organelle, both in its ultrastructure and the conservation, loss or transfer of its genes. A review of the recent literature reveals mounting evidence in support of the presence of a relic plastid in P. marinus, including the presence of multimembrane structures, characteristic metabolic pathways and proteins with a bipartite N-terminal extension. Further, these findings raise intriguing questions regarding the potential functions and unique adaptation of the putative plastid and/or plastid genes in the Perkinsozoa. In this review we analyse the above-mentioned evidence and evaluate the potential future directions and expected benefits of addressing such questions. Given the rapidly expanding molecular/genetic resources and methodological toolbox for Perkinsus spp., these organisms should complement the currently established models for investigating plastid evolution within the Chromalveolata.
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Affiliation(s)
- José A Fernández Robledo
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, IMET, Baltimore, MD 21202-3101, USA.
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Orosz F. Apicomplexan apicortins possess a long disordered N-terminal extension. INFECTION GENETICS AND EVOLUTION 2011; 11:1037-44. [DOI: 10.1016/j.meegid.2011.03.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 03/24/2011] [Accepted: 03/25/2011] [Indexed: 01/01/2023]
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Lin Z, Fernández-Robledo JA, Cellier MFM, Vasta GR. The natural resistance-associated macrophage protein from the protozoan parasite Perkinsus marinus mediates iron uptake. Biochemistry 2011; 50:6340-55. [PMID: 21661746 DOI: 10.1021/bi200343h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Microbial pathogens succeed in acquiring essential metals such as iron and manganese despite their limited availability because of the host's immune response. The eukaryotic natural resistance-associated macrophage proteins mediate uptake of divalent metals and, during infection, may compete directly for metal acquisition with the pathogens' transporters. In this study, we characterize the Nramp gene family of Perkinsus marinus, an intracellular parasite of the eastern oyster, and through yeast complementation, we demonstrate for the first time for a protozoan parasite that Nramp imports environmental Fe. Three PmNramp isogenes differ in their exon-intron structures and encode transcripts that display a trans splicing leader at the 5' end. The protein sequences share conserved properties predicted for the Nramp/Solute carrier 11 (Slc11) family, such as 12-transmembrane segment (TMS) topology (N- and C-termini cytoplasmic) and preferential conservation of four TMS predicted to form a pseudosymmetric proton/metal symport pathway. Yeast fet3fet4 mutant complementation assays showed iron transport activity for PmNramp1 and a fusion chimera of the PmNramp3 hydrophobic core and PmNramp1 N- and C-termini. PmNramp1 site-directed mutagenesis demonstrated that Slc11 invariant and predicted pseudosymmetric motifs (TMS1 Asp-Pro-Gly and TMS6 Met-Pro-His) are key for transport function. PmNramp1 TMS1 mutants D76E, G78A, and D76E/G78A prevented membrane protein expression, while TMS6 M250A, H252Y, and M250A/H252Y specifically abrogated Fe uptake; the TMS6 H252Y mutation also correlates with divergence from Nramp specificity for divalent metals.
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Affiliation(s)
- Zhuoer Lin
- Department of Microbiology and Immunology, University of Maryland School of Medicine, IMET, 701 East Pratt Street, Suite 236, Baltimore, Maryland 21202-3101, USA
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Spliced leader RNAs, mitochondrial gene frameshifts and multi-protein phylogeny expand support for the genus Perkinsus as a unique group of alveolates. PLoS One 2011; 6:e19933. [PMID: 21629701 PMCID: PMC3101222 DOI: 10.1371/journal.pone.0019933] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Accepted: 04/19/2011] [Indexed: 01/04/2023] Open
Abstract
The genus Perkinsus occupies a precarious phylogenetic position. To gain a better understanding of the relationship between perkinsids, dinoflagellates and other alveolates, we analyzed the nuclear-encoded spliced-leader (SL) RNA and mitochondrial genes, intron prevalence, and multi-protein phylogenies. In contrast to the canonical 22-nt SL found in dinoflagellates (DinoSL), P. marinus has a shorter (21-nt) and a longer (22-nt) SL with slightly different sequences than DinoSL. The major SL RNA transcripts range in size between 80–83 nt in P. marinus, and ∼83 nt in P. chesapeaki, significantly larger than the typical ≤56-nt dinoflagellate SL RNA. In most of the phylogenetic trees based on 41 predicted protein sequences, P. marinus branched at the base of the dinoflagellate clade that included the ancient taxa Oxyrrhis and Amoebophrya, sister to the clade of apicomplexans, and in some cases clustered with apicomplexans as a sister to the dinoflagellate clade. Of 104 Perkinsus spp. genes examined 69.2% had introns, a higher intron prevalence than in dinoflagellates. Examination of Perkinsus spp. mitochondrial cytochrome B and cytochrome C oxidase subunit I genes and their cDNAs revealed no mRNA editing, but these transcripts can only be translated when frameshifts are introduced at every AGG and CCC codon as if AGGY codes for glycine and CCCCU for proline. These results, along with the presence of the numerous uncharacterized ‘marine alveolate group I' and Perkinsus-like lineages separating perkinsids from core dinoflagellates, expand support for the affiliation of the genus Perkinsus with an independent lineage (Perkinsozoa) positioned between the phyla of Apicomplexa and Dinoflagellata.
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Zhang Q, Liu G, Hu Z. Morphological differences and molecular phylogeny of freshwater blooming species, Peridiniopsis spp. (Dinophyceae) from China. Eur J Protistol 2011; 47:149-60. [PMID: 21561747 DOI: 10.1016/j.ejop.2011.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 12/28/2010] [Accepted: 03/22/2011] [Indexed: 10/18/2022]
Abstract
In 2008-2010, several freshwater dinoflagellate blooms caused by Peridiniopsis spp. were observed in China. P. penardii and P. niei sampled from various geographical localities were examined by means of light and scanning electron microscopy. After comparing morphological and molecular differences, the new freshwater variety Peridiniopsis penardii var. robusta var. nov. (Peridiniales, Dinophyceae) found in Manwan Reservoir, Yunnan Province was described. The new variety differed from P. penardii since it possessed numerous robust antapical spines and a conspicuous apical spine. Molecular phylogenetic analyses based on SSU, LSU and ITS indicated P. niei, P. penardii and P. penardii var. robusta were closely related with P. kevei, and clustered into a monophyletic clade. The new variety possessed an endosymbiotic diatom which was similar to P. penardii and P. kevei, whereas the endosymbiont was not present in cells of P. niei. The endosymbiont SSU and ITS phylogenies showed that the endosymbionts of these three dinoflagellates were closely related to members of Thalassiosirales. Furthermore it was concluded that the endosymbionts might originate from Discostella-like species.
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Affiliation(s)
- Qi Zhang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
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