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Valach M, Moreira S, Petitjean C, Benz C, Butenko A, Flegontova O, Nenarokova A, Prokopchuk G, Batstone T, Lapébie P, Lemogo L, Sarrasin M, Stretenowich P, Tripathi P, Yazaki E, Nara T, Henrissat B, Lang BF, Gray MW, Williams TA, Lukeš J, Burger G. Recent expansion of metabolic versatility in Diplonema papillatum, the model species of a highly speciose group of marine eukaryotes. BMC Biol 2023; 21:99. [PMID: 37143068 PMCID: PMC10161547 DOI: 10.1186/s12915-023-01563-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 03/10/2023] [Indexed: 05/06/2023] Open
Abstract
BACKGROUND Diplonemid flagellates are among the most abundant and species-rich of known marine microeukaryotes, colonizing all habitats, depths, and geographic regions of the world ocean. However, little is known about their genomes, biology, and ecological role. RESULTS We present the first nuclear genome sequence from a diplonemid, the type species Diplonema papillatum. The ~ 280-Mb genome assembly contains about 32,000 protein-coding genes, likely co-transcribed in groups of up to 100. Gene clusters are separated by long repetitive regions that include numerous transposable elements, which also reside within introns. Analysis of gene-family evolution reveals that the last common diplonemid ancestor underwent considerable metabolic expansion. D. papillatum-specific gains of carbohydrate-degradation capability were apparently acquired via horizontal gene transfer. The predicted breakdown of polysaccharides including pectin and xylan is at odds with reports of peptides being the predominant carbon source of this organism. Secretome analysis together with feeding experiments suggest that D. papillatum is predatory, able to degrade cell walls of live microeukaryotes, macroalgae, and water plants, not only for protoplast feeding but also for metabolizing cell-wall carbohydrates as an energy source. The analysis of environmental barcode samples shows that D. papillatum is confined to temperate coastal waters, presumably acting in bioremediation of eutrophication. CONCLUSIONS Nuclear genome information will allow systematic functional and cell-biology studies in D. papillatum. It will also serve as a reference for the highly diverse diplonemids and provide a point of comparison for studying gene complement evolution in the sister group of Kinetoplastida, including human-pathogenic taxa.
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Affiliation(s)
- Matus Valach
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada.
| | - Sandrine Moreira
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada
| | - Celine Petitjean
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Corinna Benz
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Anzhelika Butenko
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Olga Flegontova
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of Ostrava, Ostrava, Czech Republic
| | - Anna Nenarokova
- School of Biological Sciences, University of Bristol, Bristol, UK
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
| | - Galina Prokopchuk
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Tom Batstone
- School of Biological Sciences, University of Bristol, Bristol, UK
- Present address: High Performance Computing Centre, Bristol, UK
| | - Pascal Lapébie
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix Marseille Université, Marseille, France
| | - Lionnel Lemogo
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada
- Present address: Environment Climate Change Canada, Dorval, QC, Canada
| | - Matt Sarrasin
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada
| | - Paul Stretenowich
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada
- Present address: Canadian Centre for Computational Genomics; McGill Genome Centre, McGill University, Montreal, QC, Canada
| | - Pragya Tripathi
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Euki Yazaki
- RIKEN Interdisciplinary Theoretical and Mathematical Sciences Program (iTHEMS), Hirosawa, Wako, Saitama, Japan
| | - Takeshi Nara
- Laboratory of Molecular Parasitology, Graduate School of Life Science and Technology, Iryo Sosei University, Iwaki City, Fukushima, Japan
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques (AFMB), CNRS, Aix Marseille Université, Marseille, France
- Present address: DTU Bioengineering, Technical University of Denmark, Lyngby, Denmark
- Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - B Franz Lang
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada
| | - Michael W Gray
- Department of Biochemistry and Molecular Biology, Institute for Comparative Genomics, Dalhousie University, Halifax, NS, Canada
| | - Tom A Williams
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Gertraud Burger
- Department of Biochemistry, Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montreal, QC, Canada.
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de Bustos A, Figueroa RI, Sixto M, Bravo I, Cuadrado Á. The 5S rRNA genes in Alexandrium: their use as a FISH chromosomal marker in studies of the diversity, cell cycle and sexuality of dinoflagellates. HARMFUL ALGAE 2020; 98:101903. [PMID: 33129460 DOI: 10.1016/j.hal.2020.101903] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/25/2020] [Accepted: 09/10/2020] [Indexed: 06/11/2023]
Abstract
Chromosomal markers of the diversity and evolution of dinoflagellates are scarce because the genomes of these organisms are unique among eukaryotes in terms of their base composition and chromosomal structure. Similarly, a lack of appropriate tools has hindered studies of the chromosomal localization of 5S ribosomal DNA (rDNA) in the nucleosome-less chromosomes of dinoflagellates. In this study, we isolated and cloned 5S rDNA sequences from various toxin-producing species of the genus Alexandrium and developed a fluorescence in situ hybridization (FISH) probe that allows their chromosomal localization. Our results can be summarized as follows: 1) The 5S rDNA unit is composed of a highly conserved 122-bp coding region and an intergenic spacer (IGS), the length and sequence of which are variable even within strains. 2) Three different IGS types, one containing the U6 small nuclear RNA (snRNA) gene, were found among four of the studied species (A. minutum, A. tamarense, A. catenella and A. pacificum). 3) In all strains investigated by FISH (A. minutum, A. tamarense, A. pacificum, A. catenella, A. andersonii and A. ostenfeldii), 5S rDNA gene arrays were separate from the nucleolar organizer region, which contains the genes for the large 45S pre-ribosomal RNA. 4) One to three 5S rDNA sites per haploid genome were detected, depending on the strains/species. Intraspecific variability in the number of 5S rDNA sites was determined among strains of A. minutum and A. pacificum. 5) 5S rDNA is a useful chromosomal marker of mitosis progression and can be employed to differentiate vegetative (haploid) vs. planozygotes (diploid) cells. Thus, the FISH probe (oligo-Dino5Smix5) developed in this study facilitates analyses of the diversity, cell cycle and life stages of the genus Alexandrium.
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Affiliation(s)
- Alfredo de Bustos
- Universidad de Alcalá (UAH), Dpto Biomedicina y Biotecnología, 28805 Alcalá de Henares, Madrid, Spain.
| | - Rosa I Figueroa
- Instituto Español de Oceanografía (IEO), Subida a Radio Faro 50, 36390 Vigo, Spain.
| | - Marta Sixto
- Instituto Español de Oceanografía (IEO), Subida a Radio Faro 50, 36390 Vigo, Spain; Campus do Mar, Facultad de Ciencias del Mar, Universidad de Vigo, 36311 Vigo, Spain.
| | - Isabel Bravo
- Instituto Español de Oceanografía (IEO), Subida a Radio Faro 50, 36390 Vigo, Spain.
| | - Ángeles Cuadrado
- Universidad de Alcalá (UAH), Dpto Biomedicina y Biotecnología, 28805 Alcalá de Henares, Madrid, Spain.
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Symonová R. Integrative rDNAomics-Importance of the Oldest Repetitive Fraction of the Eukaryote Genome. Genes (Basel) 2019; 10:genes10050345. [PMID: 31067804 PMCID: PMC6562748 DOI: 10.3390/genes10050345] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Revised: 04/17/2019] [Accepted: 04/25/2019] [Indexed: 02/06/2023] Open
Abstract
Nuclear ribosomal RNA (rRNA) genes represent the oldest repetitive fraction universal to all eukaryotic genomes. Their deeply anchored universality and omnipresence during eukaryotic evolution reflects in multiple roles and functions reaching far beyond ribosomal synthesis. Merely the copy number of non-transcribed rRNA genes is involved in mechanisms governing e.g., maintenance of genome integrity and control of cellular aging. Their copy number can vary in response to environmental cues, in cellular stress sensing, in development of cancer and other diseases. While reaching hundreds of copies in humans, there are records of up to 20,000 copies in fish and frogs and even 400,000 copies in ciliates forming thus a literal subgenome or an rDNAome within the genome. From the compositional and evolutionary dynamics viewpoint, the precursor 45S rDNA represents universally GC-enriched, highly recombining and homogenized regions. Hence, it is not accidental that both rDNA sequence and the corresponding rRNA secondary structure belong to established phylogenetic markers broadly used to infer phylogeny on multiple taxonomical levels including species delimitation. However, these multiple roles of rDNAs have been treated and discussed as being separate and independent from each other. Here, I aim to address nuclear rDNAs in an integrative approach to better assess the complexity of rDNA importance in the evolutionary context.
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Affiliation(s)
- Radka Symonová
- Faculty of Science, Department of Biology, University of Hradec Králové, 500 03 Hradec Králové, Czech Republic.
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Garcia S, Kovařík A, Leitch AR, Garnatje T. Cytogenetic features of rRNA genes across land plants: analysis of the Plant rDNA database. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 89:1020-1030. [PMID: 27943584 DOI: 10.1111/tpj.13442] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/22/2016] [Accepted: 11/24/2016] [Indexed: 05/09/2023]
Abstract
The online resource http://www.plantrdnadatabase.com/ stores information on the number, chromosomal locations and structure of the 5S and 18S-5.8S-26S (35S) ribosomal DNAs (rDNA) in plants. This resource was exploited to study relationships between rDNA locus number, distribution, the occurrence of linked (L-type) and separated (S-type) 5S and 35S rDNA units, chromosome number, genome size and ploidy level. The analyses presented summarise current knowledge on rDNA locus numbers and distribution in plants. We analysed 2949 karyotypes, from 1791 species and 86 plant families, and performed ancestral character state reconstructions. The ancestral karyotype (2n = 16) has two terminal 35S sites and two interstitial 5S sites, while the median (2n = 24) presents four terminal 35S sites and three interstitial 5S sites. Whilst 86.57% of karyotypes show S-type organisation (ancestral condition), the L-type arrangement has arisen independently several times during plant evolution. A non-terminal position of 35S rDNA was found in about 25% of single-locus karyotypes, suggesting that terminal locations are not essential for functionality and expression. Single-locus karyotypes are very common, even in polyploids. In this regard, polyploidy is followed by subsequent locus loss. This results in a decrease in locus number per monoploid genome, forming part of the diploidisation process returning polyploids to a diploid-like state over time.
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Affiliation(s)
- Sònia Garcia
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Passeig del Migdia s/n, 08038, Barcelona, Catalonia, Spain
| | - Ales Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, Brno, 612 65, Czech Republic
| | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, London E1 4NS, UK
| | - Teresa Garnatje
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Passeig del Migdia s/n, 08038, Barcelona, Catalonia, Spain
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Chairi H, Gonzalez LR. Structure and Organization of the Engraulidae Family U2 snRNA: An Evolutionary Model Gene? J Mol Evol 2015; 80:209-18. [PMID: 25838107 DOI: 10.1007/s00239-015-9674-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Accepted: 03/27/2015] [Indexed: 01/01/2023]
Abstract
The U2 snRNA multigene family has been analyzed in four species of the Engraulidae family--Engraulis encrasicolus, Engraulis mordax, Engraulis ringens, and Engraulis japonicas--with the object of understanding more about the structure of this multigene family in these pelagic species and studying their phylogenetic relationships. The results showed that the cluster of this gene family in the Engraulis genus is formed by the U2-U5 snRNA with highly conserved sequences of mini- and micro-satellites, such as (CTGT)n, embedded downstream of the transcription unit; findings indicate that this gene family evolved following the concerted model. The phylogenetic analysis of the non-transcribed spacer of cluster U2-U5 snDNA in the 4 species showed that the sequences of the species E. encrasicolus and E. japonicus are closely related; these two are genetically close to E. mordax and slightly more distant from E. ringens. The data obtained by molecular analysis of U2-U5 snDNA and their secondary structure, with the presence of the micro-satellite (CTGT)n and mini-satellites, show clearly that the species E. encrasicolus and E. japonicus are closely related and would be older than E. mordax and E. ringens.
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Affiliation(s)
- Hicham Chairi
- Laboratorio de Genética, Facultad de Ciencias del Mar y Ambientales, CACYTMAR, Universidad de Cádiz, Polígono Río San Pedro, s/n, 11510, Puerto Real, Cádiz, Spain
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Systematic analysis and evolution of 5S ribosomal DNA in metazoans. Heredity (Edinb) 2013; 111:410-21. [PMID: 23838690 DOI: 10.1038/hdy.2013.63] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2012] [Revised: 04/09/2013] [Accepted: 05/17/2013] [Indexed: 11/08/2022] Open
Abstract
Several studies on 5S ribosomal DNA (5S rDNA) have been focused on a subset of the following features in mostly one organism: number of copies, pseudogenes, secondary structure, promoter and terminator characteristics, genomic arrangements, types of non-transcribed spacers and evolution. In this work, we systematically analyzed 5S rDNA sequence diversity in available metazoan genomes, and showed organism-specific and evolutionary-conserved features. Putatively functional sequences (12,766) from 97 organisms allowed us to identify general features of this multigene family in animals. Interestingly, we show that each mammal species has a highly conserved (housekeeping) 5S rRNA type and many variable ones. The genomic organization of 5S rDNA is still under debate. Here, we report the occurrence of several paralog 5S rRNA sequences in 58 of the examined species, and a flexible genome organization of 5S rDNA in animals. We found heterogeneous 5S rDNA clusters in several species, supporting the hypothesis of an exchange of 5S rDNA from one locus to another. A rather high degree of variation of upstream, internal and downstream putative regulatory regions appears to characterize metazoan 5S rDNA. We systematically studied the internal promoters and described three different types of termination signals, as well as variable distances between the coding region and the typical termination signal. Finally, we present a statistical method for detection of linkage among noncoding RNA (ncRNA) gene families. This method showed no evolutionary-conserved linkage among 5S rDNAs and any other ncRNA genes within Metazoa, even though we found 5S rDNA to be linked to various ncRNAs in several clades.
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