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Lukáčová A, Lihanová D, Beck T, Alberty R, Vešelényiová D, Krajčovič J, Vesteg M. The Influence of Phenol on the Growth, Morphology and Cell Division of Euglena gracilis. Life (Basel) 2023; 13:1734. [PMID: 37629591 PMCID: PMC10455851 DOI: 10.3390/life13081734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/28/2023] [Accepted: 08/10/2023] [Indexed: 08/27/2023] Open
Abstract
Phenol, a monocyclic aromatic hydrocarbon with various commercial uses, is a major pollutant in industrial wastewater. Euglena gracilis is a unicellular freshwater flagellate possessing secondary chloroplasts of green algal origin. This protist has been widely used for monitoring the biological effect of various inorganic and organic environmental pollutants, including aromatic hydrocarbons. In this study, we evaluate the influence of different phenol concentrations (3.39 mM, 3.81 mM, 4.23 mM, 4.65 mM, 5.07 mM, 5.49 mM and 5.91 mM) on the growth, morphology and cell division of E. gracilis. The cell count continually decreases (p < 0.05-0.001) over time with increasing phenol concentration. While phenol treatment does not induce bleaching (permanent loss of photosynthesis), the morphological changes caused by phenol include the formation of spherical (p < 0.01-0.001), hypertrophied (p < 0.05) and monster cells (p < 0.01) and lipofuscin bodies. Phenol also induces an atypical form of cell division of E. gracilis, simultaneously producing more than 2 (3-12) viable cells from a single cell. Such atypically dividing cells have a symmetric "star"-like shape. The percentage of atypically dividing cells increases (p < 0.05) with increasing phenol concentration. Our findings suggest that E. gracilis can be used as bioindicator of phenol contamination in freshwater habitats and wastewater.
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Affiliation(s)
- Alexandra Lukáčová
- Department of Biology, Ecology and Environment, Faculty of Natural Sciences, Matej Bel University, 974 01 Banská Bystrica, Slovakia (T.B.)
| | - Diana Lihanová
- Department of Biology, Ecology and Environment, Faculty of Natural Sciences, Matej Bel University, 974 01 Banská Bystrica, Slovakia (T.B.)
| | - Terézia Beck
- Department of Biology, Ecology and Environment, Faculty of Natural Sciences, Matej Bel University, 974 01 Banská Bystrica, Slovakia (T.B.)
| | - Roman Alberty
- Department of Biology, Ecology and Environment, Faculty of Natural Sciences, Matej Bel University, 974 01 Banská Bystrica, Slovakia (T.B.)
| | - Dominika Vešelényiová
- Institute of Biology and Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 917 01 Trnava, Slovakia
| | - Juraj Krajčovič
- Institute of Biology and Biotechnology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 917 01 Trnava, Slovakia
| | - Matej Vesteg
- Department of Biology, Ecology and Environment, Faculty of Natural Sciences, Matej Bel University, 974 01 Banská Bystrica, Slovakia (T.B.)
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Lihanová D, Lukáčová A, Beck T, Jedlička A, Vešelényiová D, Krajčovič J, Vesteg M. Versatile biotechnological applications of Euglena gracilis. World J Microbiol Biotechnol 2023; 39:133. [PMID: 36959517 DOI: 10.1007/s11274-023-03585-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
Euglena gracilis is a freshwater protist possessing secondary chloroplasts of green algal origin. Various physical factors (e.g. UV) and chemical compounds (e.g. antibiotics) cause the bleaching of E. gracilis cells-the loss of plastid genes leading to the permanent inability to photosynthesize. Bleaching can be prevented by antimutagens (i.e. lignin, vitamin C and selenium). Besides screening the mutagenic and antimutagenic activity of chemicals, E. gracilis is also a suitable model for studying the biological effects of many organic pollutants. Due to its capability of heavy metal sequestration, it can be used for bioremediation. E. gracilis has been successfully transformed, offering the possibility of genetic modifications for synthesizing compounds of biotechnological interest. The novel design of the "next generation" transgenic expression cassettes with respect to the specificities of euglenid gene expression is proposed. Moreover, E. gracilis is a natural source of commercially relevant bioproducts such as (pro)vitamins, wax esters, polyunsaturated fatty acids and paramylon (β-1,3-glucan). One of the highest limitations of large-scale cultivation of E. gracilis is its disability to synthesize essential vitamins B1 and B12. This disadvantage can be overcome by co-cultivation of E. gracilis with other microorganisms, which can synthesize sufficient amounts of these vitamins. Such co-cultures can be used for the effective accumulation and harvesting of Euglena biomass by bioflocculation.
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Grants
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- VEGA 1/0694/2021 Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic, and the Academy of Sciences
- ITMS 26210120024 European Regional Development Fund
- ITMS 26210120024 European Regional Development Fund
- ITMS 26210120024 European Regional Development Fund
- ITMS 26210120024 European Regional Development Fund
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Affiliation(s)
- Diana Lihanová
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01, Banská Bystrica, Slovakia
| | - Alexandra Lukáčová
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01, Banská Bystrica, Slovakia
| | - Terézia Beck
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01, Banská Bystrica, Slovakia
| | - Andrej Jedlička
- Department of Biology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 917 01, Trnava, Slovakia
| | - Dominika Vešelényiová
- Department of Biology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 917 01, Trnava, Slovakia
| | - Juraj Krajčovič
- Department of Biology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, 917 01, Trnava, Slovakia
| | - Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01, Banská Bystrica, Slovakia.
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Lukáčová A, Beck T, Trnková K, Trniková M, Krajčovič J, Vesteg M. Discrimination of Euglena gracilis strains Z and bacillaris by MALDI-TOF MS. J Appl Microbiol 2022; 133:930-942. [PMID: 35483969 DOI: 10.1111/jam.15600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 03/31/2022] [Accepted: 04/26/2022] [Indexed: 12/01/2022]
Abstract
AIMS Euglena gracilis is used as model organism for various microbiological, molecular biological and biotechnological studies. Its most studied wild type strains are Z and bacillaris, but their discrimination by standard molecular methods is difficult. Therefore, we decided to test the suitability of MALDI-TOF MS (matrix assisted laser desorption/ionization - time of flight mass spectrometry) for identification of E. gracilis and for discrimination of these two strains possessing functional chloroplasts. MALDI-TOF MS profiling was also tested for two white (non-photosynthetic) stable E. gracilis mutant strains Wgm ZOflL and W10 BSmL. METHODS AND RESULTS We have successfully obtained main spectrum profiles (MSPs) of E. gracilis strains Z, SAG 1224-5/25 and bacillaris, SAG 1224-5/15 using protein extraction procedure. Subsequent MALDI-TOF MS profiling of a number of tested samples and the comparison of the obtained protein profiles with our in-house database including MSPs of both strains has revealed that these two strains can be easily distinguished by MALDI-TOF MS based on score values over two in most cases. This method has also confirmed the ancestry of white mutant strains Wgm ZOflL and W10 BSmL, originally derived from strains Z and bacillaris, respectively. CONCLUSIONS MALDI-TOF MS is suitable, accurate and rapid method for discrimination of E. gracilis strains. SIGNIFICANCE AND IMPACT OF STUDY These results can have broad practical implications for laboratories cultivating various strains of euglenids, and they can be applied for their discrimination by MALDI-TOF MS.
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Affiliation(s)
- Alexandra Lukáčová
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Banská Bystrica, Slovakia
| | - Terézia Beck
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Banská Bystrica, Slovakia
| | - Katarína Trnková
- Department of the Environment, Faculty of Natural Sciences, Matej Bel University, Banská Bystrica, Slovakia
| | - Miriam Trniková
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Banská Bystrica, Slovakia
| | - Juraj Krajčovič
- Department of Biology, Faculty of Natural Sciences, University of Ss. Cyril and Methodius, Trnava, Slovakia
| | - Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Banská Bystrica, Slovakia
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Euglena gracilis can grow in the mixed culture containing Cladosporium westerdijkiae, Lysinibacillus boronitolerans and Pseudobacillus badius without the addition of vitamins B1 and B12. J Biotechnol 2022; 351:50-59. [DOI: 10.1016/j.jbiotec.2022.04.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 11/15/2022]
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Heterotrophic euglenid Rhabdomonas costata resembles its phototrophic relatives in many aspects of molecular and cell biology. Sci Rep 2021; 11:13070. [PMID: 34158556 PMCID: PMC8219788 DOI: 10.1038/s41598-021-92174-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 05/28/2021] [Indexed: 02/05/2023] Open
Abstract
Euglenids represent a group of protists with diverse modes of feeding. To date, only a partial genomic sequence of Euglena gracilis and transcriptomes of several phototrophic and secondarily osmotrophic species are available, while primarily heterotrophic euglenids are seriously undersampled. In this work, we begin to fill this gap by presenting genomic and transcriptomic drafts of a primary osmotroph, Rhabdomonas costata. The current genomic assembly length of 100 Mbp is 14× smaller than that of E. gracilis. Despite being too fragmented for comprehensive gene prediction it provided fragments of the mitochondrial genome and comparison of the transcriptomic and genomic data revealed features of its introns, including several candidates for nonconventional types. A set of 39,456 putative R. costata proteins was predicted from the transcriptome. Annotation of the mitochondrial core metabolism provides the first data on the facultatively anaerobic mitochondrion of R. costata, which in most respects resembles the mitochondrion of E. gracilis with a certain level of streamlining. R. costata can synthetise thiamine by enzymes of heterogenous provenances and haem by a mitochondrial-cytoplasmic C4 pathway with enzymes orthologous to those found in E. gracilis. The low percentage of green algae-affiliated genes supports the ancestrally osmotrophic status of this species.
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Gumińska N, Zakryś B, Milanowski R. A New Type of Circular RNA derived from Nonconventional Introns in Nuclear Genes of Euglenids. J Mol Biol 2020; 433:166758. [PMID: 33316270 DOI: 10.1016/j.jmb.2020.166758] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 10/22/2022]
Abstract
Nuclear protein-coding genes of euglenids (Discoba, Euglenozoa, Euglenida) contain conventional (spliceosomal) and nonconventional introns. The latter have been found only in euglenozoans. A unique feature of nonconventional introns is the ability to form a stable and slightly conserved RNA secondary structure bringing together intron ends and placing adjacent exons in proximity. To date, little is known about the mechanism of their excision (e.g. whether it involves the spliceosome or not). The tubA gene of Euglena gracilis harbors three conventional and three nonconventional introns. While the conventional introns are excised as lariats, nonconventional introns are present in the cell solely as circular RNAs with full-length ends. Based on this discovery as well as on previous observations indicating that nonconventional introns are observed frequently at unique positions of genes, we suggest that this new type of intronic circRNA might play a role in intron mobility.
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Affiliation(s)
- Natalia Gumińska
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Center, University of Warsaw, ul. Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Bożena Zakryś
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Center, University of Warsaw, ul. Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Rafał Milanowski
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Center, University of Warsaw, ul. Żwirki i Wigury 101, 02-089 Warsaw, Poland.
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Tamaki S, Nishino K, Ogawa T, Maruta T, Sawa Y, Arakawa K, Ishikawa T. Comparative proteomic analysis of mitochondria isolated from Euglena gracilis under aerobic and hypoxic conditions. PLoS One 2019; 14:e0227226. [PMID: 31891638 PMCID: PMC6938325 DOI: 10.1371/journal.pone.0227226] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 12/13/2019] [Indexed: 12/26/2022] Open
Abstract
The unicellular microalga Euglena gracilis produces wax esters for ATP acquisition under low-oxygen conditions. The regulatory mechanism of wax ester production is not yet understood. Indeed, our previous transcriptomic analysis showed that transcript levels of genes involved in the wax ester synthesis hardly changed under hypoxic conditions, suggesting contribution of post-transcriptional regulation. In this study, we conducted a proteome analysis of E. gracilis mitochondria, as this organelle employs the fatty-acid synthesis pathway under hypoxic conditions. Mitochondria were isolated from E. gracilis SM-ZK strain treated with both aerobic and hypoxic conditions and used for shotgun proteomic analysis. Three independent proteomic analyses succeeded in identifying a total of 714 non-redundant proteins. Of these, 229 were detected in common to all experiments, and 116 were significantly recognized as differentially expressed proteins. GO enrichment analysis suggested dynamic changes in mitochondrial metabolic pathways and redox reactions under aerobic and hypoxic conditions. Protein levels of bifunctional enzymes isocitrate lyase and malate synthase in glyoxylate cycle were 1.35-fold higher under hypoxic conditions. Abundances of the propionyl-CoA synthetic enzymes, succinyl-CoA synthetase and propionyl-CoA carboxylase, were also 1.35- and 1.47-fold higher, respectively, under hypoxic conditions. Protein levels of pyruvate:NADP+ oxidoreductase, a key enzyme for anaerobic synthesis of acetyl-CoA, which serves as a C2 donor for fatty acids, showed a 1.68-fold increase under hypoxic conditions, whereas those of pyruvate dehydrogenase subunits showed a 0.77–0.81-fold decrease. Protein levels of the fatty-acid synthesis enzymes, 3-ketoacyl-CoA thiolase isoforms (KAT1 and KAT2), 3-hydroxyacyl-CoA dehydrogenases, and acyl-CoA dehydrogenase were up-regulated by 1.20- to 1.42-fold in response to hypoxic treatment. Overall, our proteomic analysis revealed that wax ester synthesis-related enzymes are up-regulated at the protein level post-transcriptionally to promote wax ester production in E. gracilis under low-oxygen conditions.
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Affiliation(s)
- Shun Tamaki
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, Japan
| | - Kohei Nishino
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, Japan
| | - Takahisa Ogawa
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, Japan
| | - Takanori Maruta
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, Japan
| | - Yoshihiro Sawa
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
| | - Kazuharu Arakawa
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, Kanagawa, Japan
| | - Takahiro Ishikawa
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Shimane, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Chiyoda-ku, Tokyo, Japan
- * E-mail:
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Vesteg M, Hadariová L, Horváth A, Estraño CE, Schwartzbach SD, Krajčovič J. Comparative molecular cell biology of phototrophic euglenids and parasitic trypanosomatids sheds light on the ancestor of Euglenozoa. Biol Rev Camb Philos Soc 2019; 94:1701-1721. [PMID: 31095885 DOI: 10.1111/brv.12523] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 01/23/2023]
Abstract
Parasitic trypanosomatids and phototrophic euglenids are among the most extensively studied euglenozoans. The phototrophic euglenid lineage arose relatively recently through secondary endosymbiosis between a phagotrophic euglenid and a prasinophyte green alga that evolved into the euglenid secondary chloroplast. The parasitic trypanosomatids (i.e. Trypanosoma spp. and Leishmania spp.) and the freshwater phototrophic euglenids (i.e. Euglena gracilis) are the most evolutionary distant lineages in the Euglenozoa phylogenetic tree. The molecular and cell biological traits they share can thus be considered as ancestral traits originating in the common euglenozoan ancestor. These euglenozoan ancestral traits include common mitochondrial presequence motifs, respiratory chain complexes containing various unique subunits, a unique ATP synthase structure, the absence of mitochondria-encoded transfer RNAs (tRNAs), a nucleus with a centrally positioned nucleolus, closed mitosis without dissolution of the nuclear membrane and nucleoli, a nuclear genome containing the unusual 'J' base (β-D-glucosyl-hydroxymethyluracil), processing of nucleus-encoded precursor messenger RNAs (pre-mRNAs) via spliced-leader RNA (SL-RNA) trans-splicing, post-transcriptional gene silencing by the RNA interference (RNAi) pathway and the absence of transcriptional regulation of nuclear gene expression. Mitochondrial uridine insertion/deletion RNA editing directed by guide RNAs (gRNAs) evolved in the ancestor of the kinetoplastid lineage. The evolutionary origin of other molecular features known to be present only in either kinetoplastids (i.e. polycistronic transcripts, compaction of nuclear genomes) or euglenids (i.e. monocistronic transcripts, huge genomes, many nuclear cis-spliced introns, polyproteins) is unclear.
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Affiliation(s)
- Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, 974 01, Banská Bystrica, Slovakia
| | - Lucia Hadariová
- Biotechnology and Biomedicine Center of the Academy of Sciences and Charles University in Vestec (BIOCEV), 252 50, Vestec, Czech Republic.,Department of Parasitology, Faculty of Science, Charles University in Prague, 128 44, Prague, Czech Republic
| | - Anton Horváth
- Department of Biochemistry, Faculty of Natural Sciences, Comenius University, 842 15, Bratislava, Slovakia
| | - Carlos E Estraño
- Department of Biological Sciences, University of Memphis, Memphis, TN, 38152-3560, USA
| | - Steven D Schwartzbach
- Department of Biological Sciences, University of Memphis, Memphis, TN, 38152-3560, USA
| | - Juraj Krajčovič
- Department of Biology, Faculty of Natural Sciences, University of ss. Cyril and Methodius, 917 01, Trnava, Slovakia
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On the Possibility of an Early Evolutionary Origin for the Spliced Leader Trans-Splicing. J Mol Evol 2017; 85:37-45. [DOI: 10.1007/s00239-017-9803-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 07/17/2017] [Indexed: 01/12/2023]
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Hadariová L, Vesteg M, Birčák E, Schwartzbach SD, Krajčovič J. An intact plastid genome is essential for the survival of colorless Euglena longa but not Euglena gracilis. Curr Genet 2016; 63:331-341. [PMID: 27553633 DOI: 10.1007/s00294-016-0641-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Revised: 08/02/2016] [Accepted: 08/13/2016] [Indexed: 12/18/2022]
Abstract
Euglena gracilis growth with antibacterial agents leads to bleaching, permanent plastid gene loss. Colorless Euglena (Astasia) longa resembles a bleached E. gracilis. To evaluate the role of bleaching in E. longa evolution, the effect of streptomycin, a plastid protein synthesis inhibitor, and ofloxacin, a plastid DNA gyrase inhibitor, on E. gracilis and E. longa growth and plastid DNA content were compared. E. gracilis growth was unaffected by streptomycin and ofloxacin. Quantitative PCR analyses revealed a time dependent loss of plastid genes in E. gracilis demonstrating that bleaching agents produce plastid gene deletions without affecting cell growth. Streptomycin and ofloxacin inhibited E. longa growth indicating that it requires plastid genes to survive. This suggests that evolutionary divergence of E. longa from E. gracilis was triggered by the loss of a cytoplasmic metabolic activity also occurring in the plastid. Plastid metabolism has become obligatory for E. longa cell growth. A process termed "intermittent bleaching", short term exposure to subsaturating concentrations of reversible bleaching agents followed by growth in the absence of a bleaching agent, is proposed as the molecular mechanism for E. longa plastid genome reduction. Various non-photosynthetic lineages could have independently arisen from their photosynthetic ancestors via a similar process.
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Affiliation(s)
- Lucia Hadariová
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynská dolina G-1, 842 15, Bratislava, Slovak Republic
| | - Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, 974 01, Banská Bystrica, Slovakia
| | - Erik Birčák
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynská dolina G-1, 842 15, Bratislava, Slovak Republic
| | | | - Juraj Krajčovič
- Department of Genetics, Faculty of Natural Sciences, Comenius University, Mlynská dolina G-1, 842 15, Bratislava, Slovak Republic. .,Department of Biology, Faculty of Natural Sciences, University of ss. Cyril and Methodius, 917 01, Trnava, Slovakia.
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Bicudo CEDM, Menezes M. Phylogeny and Classification of Euglenophyceae: A Brief Review. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00017] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Milanowski R, Gumińska N, Karnkowska A, Ishikawa T, Zakryś B. Intermediate introns in nuclear genes of euglenids - are they a distinct type? BMC Evol Biol 2016; 16:49. [PMID: 26923034 PMCID: PMC4770533 DOI: 10.1186/s12862-016-0620-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/15/2016] [Indexed: 02/05/2023] Open
Abstract
Background Nuclear genes of euglenids contain two major types of introns: conventional spliceosomal and nonconventional introns. The latter are characterized by variable non-canonical borders, RNA secondary structure that brings intron ends together, and an unknown mechanism of removal. Some researchers also distinguish intermediate introns, which combine features of both types. They form a stable RNA secondary structure and are classified into two subtypes depending on whether they contain one (intermediate/nonconventional subtype) or both (conventional/intermediate subtype) canonical spliceosomal borders. However, it has been also postulated that most introns classified as intermediate could simply be special cases of conventional or nonconventional introns. Results Sequences of tubB, hsp90 and gapC genes from six strains of Euglena agilis were obtained. They contain four, six, and two or three introns, respectively (the third intron in the gapC gene is unique for just one strain). Conventional introns were present at three positions: two in the tubB gene (at one position conventional/intermediate introns were also found) and one in the gapC gene. Nonconventional introns are present at ten positions: two in the tubB gene (at one position intermediate/nonconventional introns were also found), six in hsp90 (at four positions intermediate/nonconventional introns were also found), and two in the gapC gene. Conclusions Sequence and RNA secondary structure analyses of nonconventional introns confirmed that their most strongly conserved elements are base pairing nucleotides at positions +4, +5 and +6/ -8, −7 and −6 (in most introns CAG/CTG nucleotides were observed). It was also confirmed that the presence of the 5' GT/C end in intermediate/nonconventional introns is not the result of kinship with conventional introns, but is due to evolutionary pressure to preserve the purine at the 5' end. However, an example of a nonconventional intron with GC-AG ends was shown, suggesting the possibility of intron type conversion between nonconventional and conventional. Furthermore, an analysis of conventional introns revealed that the ability to form a stable RNA secondary structure by some introns is probably not a result of their relationship with nonconventional introns. It was also shown that acquisition of new nonconventional introns is an ongoing process and can be observed at the level of a single species. In the recently acquired intron in the gapC gene an extended direct repeats at the intron-exon junctions are present, suggesting that double-strand break repair process could be the source of new nonconventional introns. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0620-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Rafał Milanowski
- Department of Molecular Phylogenetics and Evolution, Institute of Botany, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Natalia Gumińska
- Department of Molecular Phylogenetics and Evolution, Institute of Botany, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Anna Karnkowska
- Department of Molecular Phylogenetics and Evolution, Institute of Botany, Faculty of Biology, University of Warsaw, Warsaw, Poland. .,Department of Botany, University of British Columbia, Vancouver, Canada.
| | - Takao Ishikawa
- Department of Molecular Biology, Institute of Biochemistry, Faculty of Biology, University of Warsaw, Warsaw, Poland.
| | - Bożena Zakryś
- Department of Molecular Phylogenetics and Evolution, Institute of Botany, Faculty of Biology, University of Warsaw, Warsaw, Poland.
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Dobáková E, Flegontov P, Skalický T, Lukeš J. Unexpectedly Streamlined Mitochondrial Genome of the Euglenozoan Euglena gracilis. Genome Biol Evol 2015; 7:3358-67. [PMID: 26590215 PMCID: PMC4700960 DOI: 10.1093/gbe/evv229] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/13/2015] [Indexed: 11/29/2022] Open
Abstract
In this study, we describe the mitochondrial genome of the excavate flagellate Euglena gracilis. Its gene complement is reduced as compared with the well-studied sister groups Diplonemea and Kinetoplastea. We have identified seven protein-coding genes: Three subunits of respiratory complex I (nad1, nad4, and nad5), one subunit of complex III (cob), and three subunits of complex IV (cox1, cox2, and a highly divergent cox3). Moreover, fragments of ribosomal RNA genes have also been identified. Genes encoding subunits of complex V, ribosomal proteins and tRNAs were missing, and are likely located in the nuclear genome. Although mitochondrial genomes of diplonemids and kinetoplastids possess the most complex RNA processing machineries known, including trans-splicing and editing of the uridine insertion/deletion type, respectively, our transcriptomic data suggest their total absence in E. gracilis. This finding supports a scenario in which the complex mitochondrial processing machineries of both sister groups evolved relatively late in evolution from a streamlined genome and transcriptome of their common predecessor.
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Affiliation(s)
- Eva Dobáková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic Departments of Biochemistry and Genetics, Faculty of Natural Sciences, Comenius University, Bratislava, Slovakia
| | - Pavel Flegontov
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic Life Science Research Centre, Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Tomáš Skalický
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic Faculty of Science, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic Faculty of Science, University of South Bohemia, České Budějovice (Budweis), Czech Republic Canadian Institute for Advanced Research, Toronto, Ontario, Canada
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Krajčovič J, Schwartzbach SD. Euglenoid flagellates: a multifaceted biotechnology platform. J Biotechnol 2014; 202:135-45. [PMID: 25527385 DOI: 10.1016/j.jbiotec.2014.11.035] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 11/12/2014] [Accepted: 11/20/2014] [Indexed: 01/08/2023]
Abstract
Euglenoid flagellates are mainly fresh water protists growing in highly diverse environments making them well-suited for a multiplicity of biotechnology applications. Phototrophic euglenids possesses complex chloroplasts of green algal origin bounded by three membranes. Euglena nuclear and plastid genome organization, gene structure and gene expression are distinctly different from other organisms. Our observations on the model organism Euglena gracilis indicate that transcription of both the plastid and nuclear genome is insensitive to environmental changes and that gene expression is regulated mainly at the post-transcriptional level. Euglena plastids have been proposed as a site for the production of proteins and value added metabolites of biotechnological interest. Euglena has been shown to be a suitable protist species to be used for production of several compounds that are used in the production of cosmeceuticals and nutraceuticals, such as α-tocopherol, wax esters, polyunsaturated fatty acids, biotin and tyrosine. The storage polysaccharide, paramylon, has immunostimulatory properties and has shown a promise for biomaterials production. Euglena biomass can be used as a nutritional supplement in aquaculture and in animal feed. Diverse applications of Euglena in environmental biotechnology include ecotoxicological risk assessment, heavy metal bioremediation, bioremediation of industrial wastewater and contaminated water.
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Affiliation(s)
- Juraj Krajčovič
- Department of Genetics, Faculty of Natural Sciences, Comenius University, 842 15 Bratislava, Slovakia.
| | - Steven D Schwartzbach
- Department of Biological Sciences, University of Memphis, Memphis, TN 38152-3560, USA
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A small portion of plastid transcripts is polyadenylated in the flagellate Euglena gracilis. FEBS Lett 2014; 588:783-8. [PMID: 24492004 DOI: 10.1016/j.febslet.2014.01.034] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 01/08/2014] [Accepted: 01/09/2014] [Indexed: 12/21/2022]
Abstract
Euglena gracilis possesses secondary plastids of green algal origin. In this study, E. gracilis expressed sequence tags (ESTs) derived from polyA-selected mRNA were searched and several ESTs corresponding to plastid genes were found. PCR experiments failed to detect SL sequence at the 5'-end of any of these transcripts, suggesting plastid origin of these polyadenylated molecules. Quantitative PCR experiments confirmed that polyadenylation of transcripts occurs in the Euglena plastids. Such transcripts have been previously observed in primary plastids of plants and algae as low-abundance intermediates of transcript degradation. Our results suggest that a similar mechanism exists in secondary plastids.
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Milanowski R, Karnkowska A, Ishikawa T, Zakryś B. Distribution of conventional and nonconventional introns in tubulin (α and β) genes of euglenids. Mol Biol Evol 2013; 31:584-93. [PMID: 24296662 PMCID: PMC3935182 DOI: 10.1093/molbev/mst227] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The nuclear genomes of euglenids contain three types of introns: conventional spliceosomal introns, nonconventional introns for which a splicing mechanism is unknown (variable noncanonical borders, RNA secondary structure bringing together intron ends), and so-called intermediate introns, which combine features of conventional and nonconventional introns. Analysis of two genes, tubA and tubB, from 20 species of euglenids reveals contrasting distribution patterns of conventional and nonconventional introns--positions of conventional introns are conserved, whereas those of the nonconventional ones are unique to individual species or small groups of closely related taxa. Moreover, in the group of phototrophic euglenids, 11 events of conventional intron loss versus 15 events of nonconventional intron gain were identified. A comparison of all nonconventional intron sequences highlighted the most conserved elements in their sequence and secondary structure. Our results led us to put forward two hypotheses. 1) The first one posits that mutational changes in intron sequence could lead to a change in their excision mechanism--intermediate introns would then be a transitional form between the conventional and nonconventional introns. 2) The second hypothesis concerns the origin of nonconventional introns--because of the presence of inverted repeats near their ends, insertion of MITE-like transposon elements is proposed as a possible source of new introns.
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Affiliation(s)
- Rafał Milanowski
- Department of Plant Systematics and Geography, Institute of Botany, Faculty of Biology, University of Warsaw, Warsaw, Poland
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Euglena gracilis and Trypanosomatids Possess Common Patterns in Predicted Mitochondrial Targeting Presequences. J Mol Evol 2012; 75:119-29. [DOI: 10.1007/s00239-012-9523-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 09/24/2012] [Indexed: 10/27/2022]
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Mateášiková-Kováčová B, Vesteg M, Drahovská H, Záhonová K, Vacula R, Krajčovič J. Nucleus-encoded mRNAs for Chloroplast Proteins GapA, PetA, and PsbO areTrans-spliced in the FlagellateEuglena gracilisIrrespective of Light and Plastid Function. J Eukaryot Microbiol 2012; 59:651-3. [DOI: 10.1111/j.1550-7408.2012.00634.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 04/10/2012] [Accepted: 04/14/2012] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - Hana Drahovská
- Department of Molecular Biology; Faculty of Natural Sciences; Comenius University; Mlynská dolina, 842 15 Bratislava; Slovakia
| | | | - Rostislav Vacula
- Institute of Cell Biology and Biotechnology; Faculty of Natural Sciences; Comenius University; Mlynská dolina, 842 15 Bratislava; Slovakia
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Sheiner L, Striepen B. Protein sorting in complex plastids. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:352-9. [PMID: 22683761 DOI: 10.1016/j.bbamcr.2012.05.030] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2012] [Revised: 05/25/2012] [Accepted: 05/28/2012] [Indexed: 12/11/2022]
Abstract
Taming a cyanobacterium in a pivitol event of endosymbiosis brought photosynthesis to eukaryotes, and gave rise to the plastids found in glaucophytes, red and green algae, and the descendants of the latter, the plants. Ultrastructural as well as molecular research over the last two decades has demonstrated that plastids have enjoyed surprising lateral mobility across the tree of life. Numerous independent secondary and tertiary endosymbiosis have led to a spread of plastids into a variety of, up to that point, non-photosynthetic lineages. Happily eating and subsequently domesticating one another protists conquered a wide variety of ecological niches. The elaborate evolution of secondary, or complex, plastids is reflected in the numerous membranes that bound them (three or four compared to the two membranes of the primary plastids). Gene transfer to the host nucleus is a hallmark of endosymbiosis and provides centralized cellular control. Here we review how these proteins find their way back into the stroma of the organelle and describe the advances in the understanding of the molecular mechanisms that allow protein translocation across four membranes. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
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Affiliation(s)
- Lilach Sheiner
- Center for Tropical and Emerging Global Diseases & Department of Cellular Biology, University of Georgia, 500 D.W. Brooks Drive, Athens, GA 30602, USA.
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Burki F, Hirakawa Y, Keeling PJ. Intragenomic Spread of Plastid-Targeting Presequences in the Coccolithophore Emiliania huxleyi. Mol Biol Evol 2012; 29:2109-12. [DOI: 10.1093/molbev/mss103] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Hrdá Š, Fousek J, Szabová J, Hampl V, Hampl V, Vlček Č. The plastid genome of Eutreptiella provides a window into the process of secondary endosymbiosis of plastid in euglenids. PLoS One 2012; 7:e33746. [PMID: 22448269 PMCID: PMC3308993 DOI: 10.1371/journal.pone.0033746] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Accepted: 02/16/2012] [Indexed: 11/18/2022] Open
Abstract
Euglenids are a group of protists that comprises species with diverse feeding modes. One distinct and diversified clade of euglenids is photoautotrophic, and its members bear green secondary plastids. In this paper we present the plastid genome of the euglenid Eutreptiella, which we assembled from 454 sequencing of Eutreptiella gDNA. Comparison of this genome and the only other available plastid genomes of photosynthetic euglenid, Euglena gracilis, revealed that they contain a virtually identical set of 57 protein coding genes, 24 genes fewer than the genome of Pyramimonas parkeae, the closest extant algal relative of the euglenid plastid. Searching within the transcriptomes of Euglena and Eutreptiella showed that 6 of the missing genes were transferred to the nucleus of the euglenid host while 18 have been probably lost completely. Euglena and Eutreptiella represent the deepest bifurcation in the photosynthetic clade, and therefore all these gene transfers and losses must have happened before the last common ancestor of all known photosynthetic euglenids. After the split of Euglena and Eutreptiella only one additional gene loss took place. The conservation of gene content in the two lineages of euglenids is in contrast to the variability of gene order and intron counts, which diversified dramatically. Our results show that the early secondary plastid of euglenids was much more susceptible to gene losses and endosymbiotic gene transfers than the established plastid, which is surprisingly resistant to changes in gene content.
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Affiliation(s)
- Štěpánka Hrdá
- Charles University in Prague, Faculty of Science, Department of Parasitology, Prague, Czech Republic
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Selective forces for the origin of spliceosomes. J Mol Evol 2012; 74:226-31. [PMID: 22407435 DOI: 10.1007/s00239-012-9494-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2011] [Accepted: 02/24/2012] [Indexed: 01/29/2023]
Abstract
It has been proposed that eukaryotic spliceosomes evolved from bacterial group II introns via constructive neutral changes. However, a more likely interpretation is that spliceosomes and group II introns share a common undefined RNA ancestor--a proto-spliceosome. Although, the constructive neutral evolution may have probably played some roles in the development of complexity including the evolution of modern spliceosomes, in fact, the origin, losses and the retention of spliceosomes can be explained straight-forwardly mainly by positive and negative selection: (1) proto-spliceosomes evolved in the RNA world as a mechanism to excise functional RNAs from an RNA genome and to join non-coding information (ancestral to exons) possibly designed to be degraded. (2) The complexity of proto-spliceosomes increased with the invention of protein synthesis in the RNP world and they were adopted for (a) the addition of translation signal to RNAs via trans-splicing, and for (b) the exon-shuffling such as to join together exons coding separate protein domains, to translate them as a single unit and thus to facilitate the molecular interaction of protein domains needed to be assembled to functional catalytic complexes. (3) Finally, the spliceosomes were adopted for cis-splicing of (mainly) non-coding information (contemporary introns) to yield translatable mRNAs. (4) Spliceosome-negative organisms (i.e., prokaryotes) have been selected in the DNA-protein world to save a lot of energy. (5) Spliceosome-positive organisms (i.e., eukaryotes) have been selected, because they have been completely spliceosome-dependent.
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23
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The falsifiability of the models for the origin of eukaryotes. Curr Genet 2011; 57:367-90. [DOI: 10.1007/s00294-011-0357-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 09/29/2011] [Accepted: 09/30/2011] [Indexed: 01/13/2023]
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