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Volarić M, Despot-Slade E, Veseljak D, Pavlek M, Vojvoda Zeljko T, Mravinac B, Meštrović N. The Genome Organization of 5S rRNA Genes in the Model Organism Tribolium castaneum and Its Sibling Species Tribolium freemani. Genes (Basel) 2024; 15:776. [PMID: 38927712 PMCID: PMC11202950 DOI: 10.3390/genes15060776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 06/07/2024] [Accepted: 06/11/2024] [Indexed: 06/28/2024] Open
Abstract
5S ribosomal DNAs (rDNAs) are arranged in tandem and are often under-represented in genome assemblies. In the present study, we performed a global and in-depth analysis of the 5S rDNAs in the model insect Tribolium castaneum and its closely related species Tribolium freemani. To accomplish this goal, we used our recently published genome assemblies based on Nanopore and PacBio long-read sequencing. Although these closely related species share the 5S rRNA gene sequence with high homology, they show a different organization of the 5S rDNA locus. Analysis of 5S rDNA arrays in T. castaneum revealed a typical tandemly repeated organization characterized by repeat units consisting of the 121 bp long 5S rRNA gene and the 71 bp long nontranscribed spacer (NTS). In contrast, T. freemani showed a much more complex organization of 5S rDNA arrays characterized by two patterns. The first is based on the association of 5S rRNA gene with arrays of a satellite DNA, representing the NTS sequence of the 5S rDNA genes in T. freemani. The second, more complex type is characterized by a somewhat less frequent occurrence of the 5S rRNA gene and its association with longer satellite DNA arrays that are regularly interrupted by Jockey-like retrotransposons. This organization, in which the ribosomal gene is associated with two completely different repetitive elements such as satellite DNAs and retrotransposons, suggests that the 5S rRNA gene, regardless of its crucial function in the genome, could be a subject of extremely dynamic genomic rearrangements.
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Affiliation(s)
| | | | | | | | | | | | - Nevenka Meštrović
- Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia; (M.V.); (E.D.-S.); (D.V.); (M.P.); (T.V.Z.); (B.M.)
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Chen G, Stepanenko A, Borisjuk N. Contrasting patterns of 5S rDNA repeats in European and Asian ecotypes of greater duckweed, Spirodela polyrhiza (Lemnaceae). FRONTIERS IN PLANT SCIENCE 2024; 15:1378683. [PMID: 38711607 PMCID: PMC11070557 DOI: 10.3389/fpls.2024.1378683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 04/09/2024] [Indexed: 05/08/2024]
Abstract
Ribosomal DNA (rDNA) contains highly conserved, specifically organized sequences encoding ribosomal RNAs (rRNAs) separated by variable non-transcribed intergenic spacers (NTSs) and is abundant in eukaryotic genomes. These characteristics make the rDNA an informative molecular target to study genome organization, molecular evolution, and phylogenetics. In this study, we characterized the 5S rDNA repeats in the greater duckweed Spiroldela polyrhiza, a species known for its small size, rapid growth, highly conserved genome organization, and low mutation rate. Sequence analysis of at least 12 individually cloned PCR fragments containing the 5S rDNA units for each of six ecotypes that originated from Europe (Ukraine) and Asia (China) revealed two distinct types of 5S rDNA repeats containing NTSs of different lengths and nucleotide compositions. The shorter 5S rDNA repeat units had a highly homogeneous 400-bp NTS, with few ecotype- or region-specific single-nucleotide polymorphisms (SNPs). The longer 5S rDNA units had NTSs of 1056-1084 bp with characteristic intra- and inter-genomic variants due to specific SNPs and insertions/deletions of 4-15-bp DNA elements. We also detected significant variability in the ratio of short/long 5S rDNA variants between ecotypes of S. polyrhiza. The contrasting dynamics of the two types of 5S rDNA units, combined with the unusually low repeat copy number (for plants) in S. polyrhiza (46-220 copies per genome), shows that this species could serve as an excellent model for examining the mechanisms of concerted evolution and functional significance of rDNA variability.
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Affiliation(s)
- Guimin Chen
- School of Life Sciences, Huaiyin Normal University, Huai’an, China
| | - Anton Stepanenko
- School of Life Sciences, Huaiyin Normal University, Huai’an, China
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
- Department of Molecular Genetics, Institute of Cell Biology and Genetic Engineering, Kyiv, Ukraine
| | - Nikolai Borisjuk
- School of Life Sciences, Huaiyin Normal University, Huai’an, China
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Liu J, Lin X, Wang X, Feng L, Zhu S, Tian R, Fang J, Tao A, Fang P, Qi J, Zhang L, Huang Y, Xu J. Genomic and cytogenetic analyses reveal satellite repeat signature in allotetraploid okra (Abelmoschus esculentus). BMC PLANT BIOLOGY 2024; 24:71. [PMID: 38267860 PMCID: PMC10809672 DOI: 10.1186/s12870-024-04739-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/10/2024] [Indexed: 01/26/2024]
Abstract
BACKGROUND Satellite repeats are one of the most rapidly evolving components in eukaryotic genomes and play vital roles in genome regulation, genome evolution, and speciation. As a consequence, the composition, abundance and chromosome distribution of satellite repeats often exhibit variability across various species, genome, and even individual chromosomes. However, we know little about the satellite repeat evolution in allopolyploid genomes. RESULTS In this study, we investigated the satellite repeat signature in five okra (Abelmoschus esculentus) accessions using genomic and cytogenetic methods. In each of the five accessions, we identified eight satellite repeats, which exhibited a significant level of intraspecific conservation. Through fluorescence in situ hybridization (FISH) experiments, we observed that the satellite repeats generated multiple signals and exhibited variations in copy number across chromosomes. Intriguingly, we found that five satellite repeats were interspersed with centromeric retrotransposons, signifying their involvement in centromeric satellite repeat identity. We confirmed subgenome-biased amplification patterns of these satellite repeats through existing genome assemblies or dual-color FISH, indicating their distinct dynamic evolution in the allotetraploid okra subgenome. Moreover, we observed the presence of multiple chromosomes harboring the 35 S rDNA loci, alongside another chromosomal pair carrying the 5 S rDNA loci in okra using FISH assay. Remarkably, the intensity of 35 S rDNA hybridization signals varied among chromosomes, with the signals predominantly localized within regions of relatively weak DAPI staining, associated with GC-rich heterochromatin regions. Finally, we observed a similar localization pattern between 35 S rDNA and three satellite repeats with high GC content and confirmed their origin in the intergenic spacer region of the 35 S rDNA. CONCLUSIONS Our findings uncover a unique satellite repeat signature in the allotetraploid okra, contributing to our understanding of the composition, abundance, and chromosomal distribution of satellite repeats in allopolyploid genomes, further enriching our understanding of their evolutionary dynamics in complex allopolyploid genomes.
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Affiliation(s)
- Jiarui Liu
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xinyi Lin
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Xiaojie Wang
- College of Life Science, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Liqing Feng
- College of Life Science, Fujian Normal University, Fuzhou, 350117, China
| | - Shixin Zhu
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Runmeng Tian
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jingping Fang
- College of Life Science, Fujian Normal University, Fuzhou, 350117, China
| | - Aifen Tao
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Pingping Fang
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jianmin Qi
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Liwu Zhang
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Yongji Huang
- Ministerial and Provincial Joint Innovation Centre for Safety Production of Cross-Strait Crops, College of Geography and Oceanography, Minjiang University, Fuzhou, 350108, China.
| | - Jiantang Xu
- Scientific Observing and Experimental Station of Southeastern kenaf & jute, Ministry of Agriculture and Rural Affairs of the People's Republic of China, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Fujian Provincial Key Laboratory of Crop Breeding by Design, National Engineering Research Center for Sugarcane, College of Agriculture, Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
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Sasaki M, Kobayashi T. Regulatory processes that maintain or alter ribosomal DNA stability during the repair of programmed DNA double-strand breaks. Genes Genet Syst 2023; 98:103-119. [PMID: 35922917 DOI: 10.1266/ggs.22-00046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Organisms have evolved elaborate mechanisms that maintain genome stability. Deficiencies in these mechanisms result in changes to the nucleotide sequence as well as copy number and structural variations in the genome. Genome instability has been implicated in numerous human diseases. However, genomic alterations can also be beneficial as they are an essential part of the evolutionary process. Organisms sometimes program genomic changes that drive genetic and phenotypic diversity. Therefore, genome alterations can have both positive and negative impacts on cellular growth and functions, which underscores the need to control the processes that restrict or induce such changes to the genome. The ribosomal RNA gene (rDNA) is highly abundant in eukaryotic genomes, forming a cluster where numerous rDNA copies are tandemly arrayed. Budding yeast can alter the stability of its rDNA cluster by changing the rDNA copy number within the cluster or by producing extrachromosomal rDNA circles. Here, we review the mechanisms that regulate the stability of the budding yeast rDNA cluster during repair of DNA double-strand breaks that are formed in response to programmed DNA replication fork arrest.
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Affiliation(s)
- Mariko Sasaki
- Laboratory of Genome Regeneration, Institute for Quantitative Biosciences (IQB), The University of Tokyo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo
| | - Takehiko Kobayashi
- Laboratory of Genome Regeneration, Institute for Quantitative Biosciences (IQB), The University of Tokyo
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo
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5
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Wang W, Zhang X, Garcia S, Leitch AR, Kovařík A. Intragenomic rDNA variation - the product of concerted evolution, mutation, or something in between? Heredity (Edinb) 2023; 131:179-188. [PMID: 37402824 PMCID: PMC10462631 DOI: 10.1038/s41437-023-00634-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 06/12/2023] [Accepted: 06/12/2023] [Indexed: 07/06/2023] Open
Abstract
The classical model of concerted evolution states that hundreds to thousands of ribosomal DNA (rDNA) units undergo homogenization, making the multiple copies of the individual units more uniform across the genome than would be expected given mutation frequencies and gene redundancy. While the universality of this over 50-year-old model has been confirmed in a range of organisms, advanced high throughput sequencing techniques have also revealed that rDNA homogenization in many organisms is partial and, in rare cases, even apparently failing. The potential underpinning processes leading to unexpected intragenomic variation have been discussed in a number of studies, but a comprehensive understanding remains to be determined. In this work, we summarize information on variation or polymorphisms in rDNAs across a wide range of taxa amongst animals, fungi, plants, and protists. We discuss the definition and description of concerted evolution and describe whether incomplete concerted evolution of rDNAs predominantly affects coding or non-coding regions of rDNA units and if it leads to the formation of pseudogenes or not. We also discuss the factors contributing to rDNA variation, such as interspecific hybridization, meiotic cycles, rDNA expression status, genome size, and the activity of effector genes involved in genetic recombination, epigenetic modifications, and DNA editing. Finally, we argue that a combination of approaches is needed to target genetic and epigenetic phenomena influencing incomplete concerted evolution, to give a comprehensive understanding of the evolution and functional consequences of intragenomic variation in rDNA.
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Affiliation(s)
- Wencai Wang
- Science and Technology Innovation Center, Guangzhou University of Chinese Medicine, Guangzhou, 510405, China
| | - Xianzhi Zhang
- Department of Horticulture, College of Horticulture and Landscape Architecture, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, China
| | - Sònia Garcia
- Institut Botànic de Barcelona, IBB (CSIC - Ajuntament de Barcelona), Barcelona, Spain
| | - Andrew R Leitch
- School of Biological and Behavioral Sciences, Queen Mary University of London, London, E1 4NS, UK
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, CZ-61200, Czech Republic.
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6
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Garcia S, Pascual-Díaz JP, Krumpolcová A, Kovarík A. Analysis of 5S rDNA Genomic Organization Through the RepeatExplorer2 Pipeline: A Simplified Protocol. Methods Mol Biol 2023; 2672:501-512. [PMID: 37335496 DOI: 10.1007/978-1-0716-3226-0_30] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
The ribosomal RNA genes (rDNA) are universal genome components with a housekeeping function, given the crucial role of ribosomal RNA in the synthesis of ribosomes and thus for life-on-Earth. Therefore, their genomic organization is of considerable interest for biologists, in general. Ribosomal RNA genes have also been largely used to establish phylogenetic relationships, and to identify allopolyploid or homoploid hybridization.Here, we demonstrate how high-throughput sequencing data, through graph clustering implemented in RepeatExplorer2 pipeline ( https://repeatexplorer-elixir.cerit-sc.cz/galaxy/ ), can be helpful to decipher the genomic organization of 5S rRNA genes. We show that the linear shapes of cluster graphs are reminiscent to the linked organization of 5S and 35S rDNA (L-type arrangement) while the circular graphs correspond to their separate arrangement (S-type). We further present a simplified protocol based on the paper by (Garcia et al., Front Plant Sci 11:41, 2020) about the use of graph clustering of 5S rDNA homoeologs (S-type) to identify hybridization events in the species history. We found that the graph complexity (i.e., graph circularity in this case) is related to ploidy and genome complexity, with diploids typically showing circular-shaped graphs while allopolyploids and other interspecific hybrids display more complex graphs, with usually two or more interconnected loops representing intergenic spacers. When a three-genomic comparative clustering analysis from a given hybrid (homoploid/allopolyploid) and its putative progenitor species (diploids) is performed, it is possible to identify the corresponding homoeologous 5S rRNA gene families, and to elucidate the contribution of each putative parental genome to the 5S rDNA pool of the hybrid. Thus, the analysis of 5S rDNA cluster graphs by RepeatExplorer, together with information coming from other sources (e.g., morphology, cytogenetics) is a complementary approach for the determination of allopolyploid or homoploid hybridization and even ancient introgression events.
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Affiliation(s)
- Sònia Garcia
- Institut Botànic de Barcelona (CSIC - Ajuntament de Barcelona), Barcelona, Spain
| | | | - Alice Krumpolcová
- Department of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Ales Kovarík
- Department of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
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7
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Bartha L, Mandáková T, Kovařík A, Bulzu PA, Rodde N, Mahelka V, Lysak MA, Fustier MA, Šafář J, Cápal P, Keresztes L, Banciu HL. Intact ribosomal DNA arrays of Potentilla origin detected in Erythronium nucleus suggest recent eudicot-to-monocot horizontal transfer. THE NEW PHYTOLOGIST 2022; 235:1246-1259. [PMID: 35460285 DOI: 10.1111/nph.18171] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
During our initial phylogenetic study of the monocot genus Erythronium (Liliaceae), we observed peculiar eudicot-type internal transcribed spacer (ITS) sequences in a dataset derived from genomic DNA of Erythronium dens-canis. This raised the possibility of horizontal transfer of a eudicot alien ribosomal DNA (rDNA) into the Erythronium genome. In this work we aimed to support this hypothesis by carrying out genomic, molecular, and cytogenetic analyses. Genome skimming coupled by PacBio HiFi sequencing of a bacterial artificial chromosome clone derived from flow-sorted nuclei was used to characterise the alien 45S rDNA. Integration of alien rDNA in the recipient genome was further proved by Southern blotting and fluorescence in situ hybridization using specific probes. Alien rDNA, nested among Potentilla species in phylogenetic analysis, likely entered the Erythronium lineage in the common ancestor of E. dens-canis and E. caucasicum. Transferred eudicot-type rDNA preserved its tandemly arrayed feature on a single chromosome and was found to be transcribed in the monocot host, albeit much less efficiently than the native counterpart. This study adds a new example to the rarely documented nuclear-to-nuclear jumps of DNA between eudicots and monocots while holding the scientific community continually in suspense about the mode of DNA transfer.
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Affiliation(s)
- László Bartha
- Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
| | - Terezie Mandáková
- Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
| | - Aleš Kovařík
- Laboratory of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, 61265, Brno, Czech Republic
| | - Paul-Adrian Bulzu
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, 370 05, České Budějovice, Czech Republic
| | - Nathalie Rodde
- French Plant Genomic Resource Center, INRAE-CNRGV, 31320, Castanet Tolosan, France
| | - Václav Mahelka
- Institute of Botany, Czech Academy of Sciences, 25243, Průhonice, Czech Republic
| | - Martin A Lysak
- Central European Institute of Technology (CEITEC), Masaryk University, 625 00, Brno, Czech Republic
| | | | - Jan Šafář
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, 779 00, Olomouc, Czech Republic
| | - Petr Cápal
- Institute of Experimental Botany of the Czech Academy of Sciences, Centre of the Region Haná for Biotechnological and Agricultural Research, 779 00, Olomouc, Czech Republic
| | - Lujza Keresztes
- Hungarian Department of Biology and Ecology, Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
- Centre of Systems Biology, Biodiversity and Bioresources (3B), Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
| | - Horia L Banciu
- Molecular Biology Center, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babeş-Bolyai University, 400271, Cluj-Napoca, Romania
- Centre of Systems Biology, Biodiversity and Bioresources (3B), Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
- Department of Molecular Biology and Biotechnology, Faculty of Biology and Geology, Babeş-Bolyai University, 400006, Cluj-Napoca, Romania
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Orooji F, Mirzaghaderi G, Kuo YT, Fuchs J. Variation in the Number and Position of rDNA Loci Contributes to the Diversification and Speciation in Nigella (Ranunculaceae). FRONTIERS IN PLANT SCIENCE 2022; 13:917310. [PMID: 35812971 PMCID: PMC9261981 DOI: 10.3389/fpls.2022.917310] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Nigella is a small genus belonging to the Ranunculaceae family which is presumably originated and distributed in Aegean and the adjacent Western-Irano-Turanian region. Comparative repeat analysis of N. sativa, N. damascena and N. bucharica was performed using low-pass Illumina genomic reads followed by karyotyping and FISH mapping of seven Nigella species using the in silico identified repeats and ribosomal DNA (rDNA) probes. High- and moderate-copy repeat sequences occupy 57.52, 59.01, and 64.73% of N. sativa, N. damascena and N. bucharica genomes, respectively. Roughly, half of the genomes are retrotransposons (class I transposons), while DNA transposons (class II transposons) contributed to only about 2% of the genomes. The analyzed Nigella species possess large genomes of about 7.4 to 12.4 Gbp/1C. Only two satellite repeats in N. sativa, one in N. damascena and four in N. bucharica were identified, which were mostly (peri)centromeric and represented about 1% of each genome. A high variation in number and position of 45S rDNA loci were found among Nigella species. Interestingly, in N. hispanica, each chromosome revealed at least one 45S rDNA site and one of them occurs in hemizygous condition. Based on the chromosome numbers, genome size and (peri)centromeric satellites, three karyotype groups were observed: Two with 2n = 2x = 12 and a karyotype formula of 10m + 2t (including N. sativa, N. arvensis, N. hispanica as the first group and N. damascena and N. orientalis as the second group) and a more distant group with 2n = 2x = 14 and a karyotype formula of 8m + 2st + 4t (including N. integrifolia and N. bucharica). These karyotype groups agreed with the phylogenetic analysis using ITS and rbcL sequences. We conclude that variation in (peri)centromeric sequences, number and localization of rDNA sites as well as chromosome number (dysploidy) are involved in the diversification of the genus Nigella.
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Affiliation(s)
- Fatemeh Orooji
- Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran
| | - Ghader Mirzaghaderi
- Department of Agronomy and Plant Breeding, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran
| | - Yi-Tzu Kuo
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
| | - Jörg Fuchs
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), Gatersleben, Germany
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9
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Hemleben V, Grierson D, Borisjuk N, Volkov RA, Kovarik A. Personal Perspectives on Plant Ribosomal RNA Genes Research: From Precursor-rRNA to Molecular Evolution. FRONTIERS IN PLANT SCIENCE 2021; 12:797348. [PMID: 34992624 PMCID: PMC8724763 DOI: 10.3389/fpls.2021.797348] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/26/2021] [Indexed: 06/13/2023]
Abstract
The history of rDNA research started almost 90 years ago when the geneticist, Barbara McClintock observed that in interphase nuclei of maize the nucleolus was formed in association with a specific region normally located near the end of a chromosome, which she called the nucleolar organizer region (NOR). Cytologists in the twentieth century recognized the nucleolus as a common structure in all eukaryotic cells, using both light and electron microscopy and biochemical and genetic studies identified ribosomes as the subcellular sites of protein synthesis. In the mid- to late 1960s, the synthesis of nuclear-encoded rRNA was the only system in multicellular organisms where transcripts of known function could be isolated, and their synthesis and processing could be studied. Cytogenetic observations of NOR regions with altered structure in plant interspecific hybrids and detailed knowledge of structure and function of rDNA were prerequisites for studies of nucleolar dominance, epistatic interactions of rDNA loci, and epigenetic silencing. In this article, we focus on the early rDNA research in plants, performed mainly at the dawn of molecular biology in the 60 to 80-ties of the last century which presented a prequel to the modern genomic era. We discuss - from a personal view - the topics such as synthesis of rRNA precursor (35S pre-rRNA in plants), processing, and the organization of 35S and 5S rDNA. Cloning and sequencing led to the observation that the transcribed and processed regions of the rRNA genes vary enormously, even between populations and species, in comparison with the more conserved regions coding for the mature rRNAs. Epigenetic phenomena and the impact of hybridization and allopolyploidy on rDNA expression and homogenization are discussed. This historical view of scientific progress and achievements sets the scene for the other articles highlighting the immense progress in rDNA research published in this special issue of Frontiers in Plant Science on "Molecular organization, evolution, and function of ribosomal DNA."
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Affiliation(s)
- Vera Hemleben
- Center of Plant Molecular Biology (ZMBP), University of Tübingen, Tübingen, Germany
| | - Donald Grierson
- Plant and Crop Sciences Division, School of Biosciences, University of Nottingham, Sutton Bonington Campus, Loughborough, United Kingdom
| | - Nikolai Borisjuk
- School of Life Sciences, Huaiyin Normal University, Huai'an, China
| | - Roman A. Volkov
- Department of Molecular Genetics and Biotechnology, Yuriy Fedkovych Chernivtsi National University, Chernivtsi, Ukraine
| | - Ales Kovarik
- Laboratory of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czechia
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10
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Goffová I, Fajkus J. The rDNA Loci-Intersections of Replication, Transcription, and Repair Pathways. Int J Mol Sci 2021; 22:1302. [PMID: 33525595 PMCID: PMC7865372 DOI: 10.3390/ijms22031302] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 01/25/2021] [Accepted: 01/25/2021] [Indexed: 12/28/2022] Open
Abstract
Genes encoding ribosomal RNA (rDNA) are essential for cell survival and are particularly sensitive to factors leading to genomic instability. Their repetitive character makes them prone to inappropriate recombinational events arising from collision of transcriptional and replication machineries, resulting in unstable rDNA copy numbers. In this review, we summarize current knowledge on the structure and organization of rDNA, its role in sensing changes in the genome, and its linkage to aging. We also review recent findings on the main factors involved in chromatin assembly and DNA repair in the maintenance of rDNA stability in the model plants Arabidopsis thaliana and the moss Physcomitrella patens, providing a view across the plant evolutionary tree.
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Affiliation(s)
- Ivana Goffová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, CZ-61137 Brno, Czech Republic;
- Chromatin Molecular Complexes, Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, CZ-62500 Brno, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, CZ-61137 Brno, Czech Republic;
- Chromatin Molecular Complexes, Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, CZ-62500 Brno, Czech Republic
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, CZ-61265 Brno, Czech Republic
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11
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He J, Lin S, Yu Z, Song A, Guan Z, Fang W, Chen S, Zhang F, Jiang J, Chen F, Wang H. Identification of 5S and 45S rDNA sites in Chrysanthemum species by using oligonucleotide fluorescence in situ hybridization (Oligo-FISH). Mol Biol Rep 2021; 48:21-31. [PMID: 33454907 DOI: 10.1007/s11033-020-06102-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 12/16/2020] [Indexed: 12/13/2022]
Abstract
Fluorescence in situ hybridization (FISH) is a conventional method used to visualize the distribution of DNA elements within a genome. To examine the relationships within the Chrysanthemum genus, ribosomal DNA (rDNA), a popular cytogenetic marker, was utilized as a probe for FISH within this genus. Based on the genome data of Chrysanthemum nankingense, C. seticuspe and its allied genera in the Compositae(Asteraceae), we explored rDNA sequences to design oligonucleotide probes and perform oligonucleotide fluorescence in situ hybridization (Oligo-FISH) in eight Chrysanthemum accessions. The results showed that the majority of 5S rDNA signals were located in subterminal chromosome regions and that the number of 5S rDNA sites might be tightly associated with ploidy. For 45S rDNA sites, the number and intensity of signals differed from those of previously investigated Chrysanthemum resources. These findings may provide an optimally reliable method of examining the chromosome composition and structural variation of Chrysanthemum and its related species and allow researchers to understand the evolutionary history and phylogenetic relationships of Chrysanthemum.
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Affiliation(s)
- Jun He
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Sisi Lin
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Zhongyu Yu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Aiping Song
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Zhiyong Guan
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Weimin Fang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Sumei Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Fei Zhang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Jiafu Jiang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Fadi Chen
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China
| | - Haibin Wang
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, Key Laboratory of Landscaping, Ministry of Agriculture, College of Horticulture, Nanjing Agricultural University, Nanjing, China.
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12
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Fehrer J, Slavíková R, Paštová L, Josefiová J, Mráz P, Chrtek J, Bertrand YJK. Molecular Evolution and Organization of Ribosomal DNA in the Hawkweed Tribe Hieraciinae (Cichorieae, Asteraceae). FRONTIERS IN PLANT SCIENCE 2021; 12:647375. [PMID: 33777082 PMCID: PMC7994888 DOI: 10.3389/fpls.2021.647375] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 02/19/2021] [Indexed: 05/14/2023]
Abstract
Molecular evolution of ribosomal DNA can be highly dynamic. Hundreds to thousands of copies in the genome are subject to concerted evolution, which homogenizes sequence variants to different degrees. If well homogenized, sequences are suitable for phylogeny reconstruction; if not, sequence polymorphism has to be handled appropriately. Here we investigate non-coding rDNA sequences (ITS/ETS, 5S-NTS) along with the chromosomal organization of their respective loci (45S and 5S rDNA) in diploids of the Hieraciinae. The subtribe consists of genera Hieracium, Pilosella, Andryala, and Hispidella and has a complex evolutionary history characterized by ancient intergeneric hybridization, allele sharing among species, and incomplete lineage sorting. Direct or cloned Sanger sequences and phased alleles derived from Illumina genome sequencing were subjected to phylogenetic analyses. Patterns of homogenization and tree topologies based on the three regions were compared. In contrast to most other plant groups, 5S-NTS sequences were generally better homogenized than ITS and ETS sequences. A novel case of ancient intergeneric hybridization between Hispidella and Hieracium was inferred, and some further incongruences between the trees were found, suggesting independent evolution of these regions. In some species, homogenization of ITS/ETS and 5S-NTS sequences proceeded in different directions although the 5S rDNA locus always occurred on the same chromosome with one 45S rDNA locus. The ancestral rDNA organization in the Hieraciinae comprised 4 loci of 45S rDNA in terminal positions and 2 loci of 5S rDNA in interstitial positions per diploid genome. In Hieracium, some deviations from this general pattern were found (3, 6, or 7 loci of 45S rDNA; three loci of 5S rDNA). Some of these deviations concerned intraspecific variation, and most of them occurred at the tips of the tree or independently in different lineages. This indicates that the organization of rDNA loci is more dynamic than the evolution of sequences contained in them and that locus number is therefore largely unsuitable to inform about species relationships in Hieracium. No consistent differences in the degree of sequence homogenization and the number of 45S rDNA loci were found, suggesting interlocus concerted evolution.
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Affiliation(s)
- Judith Fehrer
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
- *Correspondence: Judith Fehrer,
| | - Renáta Slavíková
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
| | | | - Jiřina Josefiová
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
| | - Patrik Mráz
- Department of Botany, Charles University, Prague, Czechia
| | - Jindřich Chrtek
- Institute of Botany, Czech Academy of Sciences, Průhonice, Czechia
- Department of Botany, Charles University, Prague, Czechia
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Hoang PTN, Fiebig A, Novák P, Macas J, Cao HX, Stepanenko A, Chen G, Borisjuk N, Scholz U, Schubert I. Chromosome-scale genome assembly for the duckweed Spirodela intermedia, integrating cytogenetic maps, PacBio and Oxford Nanopore libraries. Sci Rep 2020; 10:19230. [PMID: 33154426 PMCID: PMC7645714 DOI: 10.1038/s41598-020-75728-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 10/13/2020] [Indexed: 11/16/2022] Open
Abstract
Duckweeds are small, free-floating, morphologically highly reduced organisms belonging to the monocot order Alismatales. They display the most rapid growth among flowering plants, vary ~ 14-fold in genome size and comprise five genera. Spirodela is the phylogenetically oldest genus with only two mainly asexually propagating species: S. polyrhiza (2n = 40; 160 Mbp/1C) and S. intermedia (2n = 36; 160 Mbp/1C). This study combined comparative cytogenetics and de novo genome assembly based on PacBio, Illumina and Oxford Nanopore (ON) reads to obtain the first genome reference for S. intermedia and to compare its genomic features with those of the sister species S. polyrhiza. Both species' genomes revealed little more than 20,000 putative protein-coding genes, very low rDNA copy numbers and a low amount of repetitive sequences, mainly Ty3/gypsy retroelements. The detection of a few new small chromosome rearrangements between both Spirodela species refined the karyotype and the chromosomal sequence assignment for S. intermedia.
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Affiliation(s)
- Phuong T N Hoang
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Stadt Seeland, Germany
- Biology Faculty, Dalat University, District 8, Dalat City, Lamdong Province, Vietnam
| | - Anne Fiebig
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Stadt Seeland, Germany
| | - Petr Novák
- Biology Centre, Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic
| | - Jiří Macas
- Biology Centre, Czech Academy of Sciences, Institute of Plant Molecular Biology, České Budějovice, 37005, Czech Republic
| | - Hieu X Cao
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Stadt Seeland, Germany
- Institute of Biology, Martin-Luther-University Halle-Wittenberg, 06120, Halle, Germany
| | - Anton Stepanenko
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huai'an, 223300, China
- Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Guimin Chen
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huai'an, 223300, China
- Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Nikolai Borisjuk
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology Around Hongze Lake, School of Life Sciences, Huaiyin Normal University, Huai'an, 223300, China
- Jiangsu Collaborative Innovation Centre of Regional Modern Agriculture and Environmental Protection, Huaiyin Normal University, Huai'an, 223300, China
| | - Uwe Scholz
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Stadt Seeland, Germany
| | - Ingo Schubert
- Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), 06466, Gatersleben, Stadt Seeland, Germany.
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14
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Havlová K, Fajkus J. G4 Structures in Control of Replication and Transcription of rRNA Genes. FRONTIERS IN PLANT SCIENCE 2020; 11:593692. [PMID: 33133121 PMCID: PMC7579416 DOI: 10.3389/fpls.2020.593692] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/22/2020] [Indexed: 06/11/2023]
Abstract
Genes encoding 45S ribosomal RNA (rDNA) are known for their abundance within eukaryotic genomes and for their unstable copy numbers in response to changes in various genetic and epigenetic factors. Commonly, we understand as epigenetic factors (affecting gene expression without a change in DNA sequence), namely DNA methylation, histone posttranslational modifications, histone variants, RNA interference, nucleosome remodeling and assembly, and chromosome position effect. All these were actually shown to affect activity and stability of rDNA. Here, we focus on another phenomenon - the potential of DNA containing shortly spaced oligo-guanine tracts to form quadruplex structures (G4). Interestingly, sites with a high propensity to form G4 were described in yeast, animal, and plant rDNAs, in addition to G4 at telomeres, some gene promoters, and transposons, suggesting the evolutionary ancient origin of G4 as a regulatory module. Here, we present examples of rDNA promoter regions with extremely high potential to form G4 in two model plants, Arabidopsis thaliana and Physcomitrella patens. The high G4 potential is balanced by the activity of G4-resolving enzymes. The ability of rDNA to undergo these "structural gymnastics" thus represents another layer of the rich repertoire of epigenetic regulations, which is pronounced in rDNA due to its highly repetitive character.
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Affiliation(s)
- Kateřina Havlová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
- Chromatin Molecular Complexes, Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czechia
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Brno, Czechia
- Chromatin Molecular Complexes, Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Brno, Czechia
- Department of Cell Biology and Radiobiology, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
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15
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Sousa A, Bechteler J, Temsch EM, Renner SS. Different from tracheophytes, liverworts commonly have mixed 35S and 5S arrays. ANNALS OF BOTANY 2020; 125:1057-1064. [PMID: 32064492 PMCID: PMC7262461 DOI: 10.1093/aob/mcaa027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 02/14/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND AND AIMS Unlike other nuclear genes in eukaryotes, rDNA genes (5S and 35S loci) are present in numerous copies per cell and, when stained, can therefore provide basic information about genome organization. In tracheophytes (vascular plants), they are usually located on separate chromosomes, the so-called S-type organization. An analysis of 1791 species of land plants suggested that S-type arrays might be ancestral in land plants, while linked (L-type) organization may be derived. However, no outgroup and only a handful of ferns and bryophytes were included. METHODS We analysed genome sizes and the distribution of telomere, 5S and 35S rDNA FISH signals in up to 12 monoicous or dioicous species of liverworts from throughout a phylogeny that includes 287 of the 386 currently recognized genera. We also used the phylogeny to plot chromosome numbers and the occurrence of visibly distinct sex chromosomes. KEY RESULTS Chromosome numbers are newly reported for the monoicous Lejeunea cavifolia and for females of the dioicous Scapania aequiloba. We detected sex-related differences in the number of rDNA signals in the dioicous Plagiochila asplenioides and Frullania dilatata. In the latter, the presence of two UU chromosomes in females and additional 5S-35S rDNA loci result in a haploid genome 0.2082 pg larger than the male genome; sex-specific genome differences in the other dioicous species were small. Four species have S-type rDNA, while five species have mixed L-S rDNA organization, and transitions may have occurred multiple times, as suggested by rDNA loci not being conserved among closely related species of Pellia. All species shared an Arabidopsis-like telomere motif, and its detection allowed verification of the chromosome number of Radula complanata and chromosome rearrangements in Aneura pinguis and P. asplenioides, the latter also showing sex-specific interstitial telomere repeats. CONCLUSIONS The S and L rDNA arrangements appear to have evolved repeatedly within liverworts, even in the same species. Evidence for differential accumulation of rDNA between the sexes so far is limited.
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Affiliation(s)
- Aretuza Sousa
- Department of Biology, University of Munich (LMU), Munich, Germany
| | - Julia Bechteler
- Nees Institute for Biodiversity of Plants, University of Bonn, Bonn, Germany
| | - Eva M Temsch
- Department of Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Susanne S Renner
- Department of Biology, University of Munich (LMU), Munich, Germany
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Matyášek R, Krumpolcová A, Lunerová J, Mikulášková E, Rosselló JA, Kovařík A. Unique Epigenetic Features of Ribosomal RNA Genes (rDNA) in Early Diverging Plants (Bryophytes). FRONTIERS IN PLANT SCIENCE 2019; 10:1066. [PMID: 31543890 PMCID: PMC6739443 DOI: 10.3389/fpls.2019.01066] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 08/06/2019] [Indexed: 05/03/2023]
Abstract
Introduction: In plants, the multicopy genes encoding ribosomal RNA (rDNA) typically exhibit heterochromatic features and high level of DNA methylation. Here, we explored rDNA methylation in early diverging land plants from Bryophyta (15 species, 14 families) and Marchantiophyta (4 species, 4 families). DNA methylation was investigated by methylation-sensitive Southern blot hybridization in all species. We also carried out whole genomic bisulfite sequencing in Polytrichum formosum (Polytrichaceae) and Dicranum scoparium (Dicranaceae) and used available model plant methyloms (Physcomitrella patents and Marchantia polymorpha) to determine rDNA unit-wide methylation patterns. Chromatin structure was analyzed using fluorescence in situ hybridization (FISH) and immunoprecipitation (CHIP) assays. Results: In contrast to seed plants, bryophyte rDNAs were efficiently digested with methylation-sensitive enzymes indicating no or low levels of CG and CHG methylation in these loci. The rDNA methylom analyses revealed variation between species ranging from negligible (<3%, P. formosum, P. patens) to moderate (7 and 17% in M. polymorpha and D. scoparium, respectively) methylation levels. There were no differences between coding and noncoding parts of rDNA units and between gametophyte and sporophyte tissues. However, major satellite repeat and transposable elements were heavily methylated in P. formosum and D. scoparium. In P. formosum rDNA, the euchromatic H3K4m3 and heterochromatic H3K9m2 histone marks were nearly balanced contrasting the angiosperms data where H3K9m2 typically dominates rDNA chromatin. In moss interphase nuclei, rDNA was localized at the nucleolar periphery and its condensation level was high. Conclusions: Unlike seed plants, the rRNA genes seem to escape global methylation machinery in bryophytes. Distinct epigenetic features may be related to rDNA expression and the physiology of these early diverging plants that exist in haploid state for most of their life cycles.
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Affiliation(s)
- Roman Matyášek
- Department of Molecular Epigenetics, Institute of Biophysics of the Czech Academy of Sciences, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
| | - Alice Krumpolcová
- Department of Molecular Epigenetics, Institute of Biophysics of the Czech Academy of Sciences, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
| | - Jana Lunerová
- Department of Molecular Epigenetics, Institute of Biophysics of the Czech Academy of Sciences, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
| | - Eva Mikulášková
- Department of Botany and Zoology, Masaryk University, Brno, Czechia
| | - Josep A. Rosselló
- Jardín Botánico, ICBiBE-Unidad Asociada CSIC, Universidad de Valencia, Valencia, Spain
| | - Aleš Kovařík
- Department of Molecular Epigenetics, Institute of Biophysics of the Czech Academy of Sciences, Institute of Biophysics of the Czech Academy of Sciences, Brno, Czechia
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17
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Goffová I, Vágnerová R, Peška V, Franek M, Havlová K, Holá M, Zachová D, Fojtová M, Cuming A, Kamisugi Y, Angelis KJ, Fajkus J. Roles of RAD51 and RTEL1 in telomere and rDNA stability in Physcomitrella patens. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 98:1090-1105. [PMID: 30834585 DOI: 10.1111/tpj.14304] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/21/2019] [Accepted: 02/27/2019] [Indexed: 05/11/2023]
Abstract
Telomeres and ribosomal RNA genes (rDNA) are essential for cell survival and particularly sensitive to factors affecting genome stability. Here, we examine the role of RAD51 and its antagonist, RTEL1, in the moss Physcomitrella patens. In corresponding mutants, we analyse their sensitivity to DNA damage, the maintenance of telomeres and rDNA, and repair of double-stranded breaks (DSBs) induced by genotoxins with various modes of action. While the loss of RTEL1 results in rapid telomere shortening, concurrent loss of both RAD51 genes has no effect on telomere lengths. We further demonstrate here the linked arrangement of 5S and 45S rRNA genes in P. patens. The spacer between 5S and 18S rRNA genes, especially the region downstream from the transcription start site, shows conspicuous clustering of sites with a high propensity to form quadruplex (G4) structures. Copy numbers of 5S and 18S rDNA are reduced moderately in the pprtel1 mutant, and significantly in the double pprad51-1-2 mutant, with no progression during subsequent cultivation. While reductions in 45S rDNA copy numbers observed in pprtel1 and pprad51-1-2 plants apply also to 5S rDNA, changes in transcript levels are different for 45S and 5S rRNA, indicating their independent transcription by RNA polymerase I and III, respectively. The loss of SOL (Sog One-Like), a transcription factor regulating numerous genes involved in DSB repair, increases the rate of DSB repair in dividing as well as differentiated tissue, and through deactivation of G2/M cell-cycle checkpoint allows the cell-cycle progression manifested as a phenotype resistant to bleomycin.
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Affiliation(s)
- Ivana Goffová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Radka Vágnerová
- The Czech Academy of Sciences, Institute of Experimental Botany, Na Karlovce 1, CZ-16000, Prague, Czech Republic
| | - Vratislav Peška
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65, Brno, Czech Republic
| | - Michal Franek
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Kateřina Havlová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Marcela Holá
- The Czech Academy of Sciences, Institute of Experimental Botany, Na Karlovce 1, CZ-16000, Prague, Czech Republic
| | - Dagmar Zachová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Miloslava Fojtová
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
| | - Andrew Cuming
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Yasuko Kamisugi
- Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, UK
| | - Karel J Angelis
- The Czech Academy of Sciences, Institute of Experimental Botany, Na Karlovce 1, CZ-16000, Prague, Czech Republic
| | - Jiří Fajkus
- Laboratory of Functional Genomics and Proteomics, National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kotlářská 2, CZ-61137, Brno, Czech Republic
- Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology, Masaryk University, Kamenice 5, CZ-62500, Brno, Czech Republic
- The Czech Academy of Sciences, Institute of Biophysics, Královopolská 135, 612 65, Brno, Czech Republic
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18
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Renner S, Sousa dos Santos A. The organization of nuclear ribosomal DNA in gnetophytes - physically separate and physically linked arrangements of 35S and 5S genes. A commentary on: 'Remarkable variation of ribosomal DNA organization and copy number in gnetophytes, a distinct lineage of gymnosperms'. ANNALS OF BOTANY 2019; 123:vi-vii. [PMID: 31106810 PMCID: PMC6526311 DOI: 10.1093/aob/mcz056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
This article comments on: Wencai Wang, Tao Wan, Hannes Becher, Alena Kuderova, Ilia J. Leitch, Sonia Garcia, Andrew R. Leitch and Aleš Kovařík. 2019. Remarkable variation of ribosomal DNA organization and copy number in gnetophytes, a distinct lineage of gymnosperms. Annals of Botany 123(5): 767–781.
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Affiliation(s)
- Susanne Renner
- University of Munich (LMU), Systematic Botany and Mycology, Munich, Germany
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19
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Wang W, Wan T, Becher H, Kuderova A, Leitch IJ, Garcia S, Leitch AR, Kovařík A. Remarkable variation of ribosomal DNA organization and copy number in gnetophytes, a distinct lineage of gymnosperms. ANNALS OF BOTANY 2019; 123:767-781. [PMID: 30265284 PMCID: PMC6526317 DOI: 10.1093/aob/mcy172] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 09/04/2018] [Indexed: 05/10/2023]
Abstract
INTRODUCTION Gnetophytes, comprising the genera Ephedra, Gnetum and Welwitschia, are an understudied, enigmatic lineage of gymnosperms with a controversial phylogenetic relationship to other seed plants. Here we examined the organization of ribosomal DNA (rDNA) across representative species. METHODS We applied high-throughput sequencing approaches to isolate and reconstruct rDNA units and to determine their intragenomic homogeneity. In addition, fluorescent in situ hybridization and Southern blot hybridization techniques were used to reveal the chromosome and genomic organization of rDNA. KEY RESULTS The 5S and 35S rRNA genes were separate (S-type) in Gnetum montanum, Gnetum gnemon and Welwitschia mirabilis and linked (L-type) in Ephedra altissima. There was considerable variability in 5S rDNA abundance, ranging from as few as ~4000 (W. mirabilis) to >100 000 (G. montanum) copies. A similar large variation was also observed in 5S rDNA locus numbers (two to 16 sites per diploid cell). 5S rRNA pseudogenes were interspersed between functional genes forming a single unit in E. altissima and G. montanum. Their copy number was comparable or even higher than that of functional 5S rRNA genes. In E. altissima internal transcribed spacers of 35S rDNA were long and intrinsically repetitive while in G. montanum and W. mirabilis they were short without the subrepeats. CONCLUSIONS Gnetophytes are distinct from other gymnosperms and angiosperms as they display surprisingly large variability in rDNA organization and rDNA copy and locus numbers between genera, with no relationship between copy numbers and genome sizes apparent. Concerted evolution of 5S rDNA units seems to have led to the amplification of 5S pseudogenes in both G. montanum and E. altissima. Evolutionary patterns of rDNA show both gymnosperm and angiosperm features underlining the diversity of the group.
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Affiliation(s)
- Wencai Wang
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Tao Wan
- Key Laboratory of Southern Subtropical Plant Diversity, Fairy Lake Botanical Garden, Shenzhen and Chinese Academy of Sciences, Shenzen, PR China
- Sino-Africa Joint Research Center, Chinese Academy of Science, Wuhan, PR China
| | - Hannes Becher
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Alena Kuderova
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
| | - Ilia J Leitch
- Jodrell Laboratory, Royal Botanic Gardens, Kew, Richmond, UK
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Passeig del Migdia s/n, Parc de Montjuïc, Barcelona, Catalonia, Spain
| | - Andrew R Leitch
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic
- For correspondence. E-mail
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20
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Tamayo-Ordóñez YJ, Narváez-Zapata JA, Tamayo-Ordóñez MC, Sánchez-Teyer LF. Retroelements and DNA Methylation Could Contribute to Diversity of 5S rDNA in Agave L. J Mol Evol 2018; 86:404-423. [DOI: 10.1007/s00239-018-9856-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 07/03/2018] [Indexed: 01/21/2023]
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21
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Waminal NE, Pellerin RJ, Kim NS, Jayakodi M, Park JY, Yang TJ, Kim HH. Rapid and Efficient FISH using Pre-Labeled Oligomer Probes. Sci Rep 2018; 8:8224. [PMID: 29844509 PMCID: PMC5974128 DOI: 10.1038/s41598-018-26667-z] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Accepted: 05/17/2018] [Indexed: 12/29/2022] Open
Abstract
Fluorescence in situ hybridization (FISH) is used to visualize the distribution of DNA elements within a genome. Conventional methods for FISH take 1-2 days. Here, we developed a simplified, rapid FISH technique using pre-labeled oligonucleotide probes (PLOPs) and tested the procedure using 18 PLOPs from 45S and 5S rDNA, Arabidopsis-type telomere, and newly-identified Panax ginseng-specific tandem repeats. The 16 developed rDNA PLOPs can be universally applied to plants and animals. The telomere PLOPs can be utilized in most plants with Arabidopsis-type telomeres. The ginseng-specific PLOP can be used to distinguish P. ginseng from related Panax species. Differential labeling of PLOPs allowed us to simultaneously visualize different target loci while reducing the FISH hybridization time from ~16 h to 5 min. PLOP-FISH is efficient, reliable, and rapid, making it ideal for routine analysis, especially of newly sequenced genomes using either universal or specific targets, such as novel tandem repeats identified from whole-genome sequencing data.
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Affiliation(s)
- Nomar Espinosa Waminal
- Chromosome Research Institute, Department of Life Science, Sahmyook University, Seoul, 01795, Korea.,Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Remnyl Joyce Pellerin
- Chromosome Research Institute, Department of Life Science, Sahmyook University, Seoul, 01795, Korea
| | - Nam-Soo Kim
- Department of Molecular Biosciences, Kangwon National University, Chuncheon, 24341, Korea
| | - Murukarthick Jayakodi
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Jee Young Park
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea
| | - Tae-Jin Yang
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Korea.
| | - Hyun Hee Kim
- Chromosome Research Institute, Department of Life Science, Sahmyook University, Seoul, 01795, Korea.
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22
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Marinho AC, Vasconcelos S, Vasconcelos EV, Marques DA, Benko-Iseppon AM, Brasileiro-Vidal AC. Karyotype and genome size comparative analyses among six species of the oilseed-bearing genus Jatropha (Euphorbiaceae). Genet Mol Biol 2018; 41:442-449. [PMID: 29767665 PMCID: PMC6082239 DOI: 10.1590/1678-4685-gmb-2017-0120] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Accepted: 09/19/2017] [Indexed: 01/08/2023] Open
Abstract
Jatropha is an important genus of Euphorbiaceae, with species largely used for various purposes, including the manufacturing of soaps and pharmaceutical products and applications in the bioenergetic industry. Although there have been several studies focusing J. curcas in various aspects, the karyotype features of Jatropha species are poorly known. Therefore, we analyzed six Jatropha species through fluorochrome staining (CMA/DAPI), fluorescent in situ hybridization (FISH) with 5S and 45S rDNA probes and genome size estimation by flow cytometry. Our results revealed several chromosome markers by both CMA/DAPI and FISH for the analyzed species. Five Jatropha species (J. curcas, J. gossypiifolia, J. integerrima, J. multifida and J. podagrica) showed four CMA-positive (CMA+) bands associated with the 5S and 45S rDNA sites (one and two pairs, respectively). However, J. mollissima displayed six CMA+/DAPI- bands co-localized with both 5S and 45S rDNA, which showed a FISH superposition. A gradual variation in the genome sizes was observed (2C = 0.64 to 0.86 pg), although an association between evidenced heterochromatin and genome sizes was not found among species. Except for the unique banding pattern of J. mollissima and the pericentromeric heterochromatin of J. curcas and J. podagrica, our data evidenced relatively conserved karyotypes.
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Affiliation(s)
- Anne C.T.A. Marinho
- Universidade Federal de
PernambucoUniversidade Federal de
PernambucoDepartment of GeneticsRecifePEBrazilDepartment of Genetics, Universidade
Federal de Pernambuco, Recife, PE, Brazil
| | - Santelmo Vasconcelos
- Instituto Tecnológico ValeInstituto Tecnológico ValeBelémPABrazilInstituto Tecnológico Vale, Belém, PA,
Brazil
| | - Emanuelle V. Vasconcelos
- Universidade Federal de
PernambucoUniversidade Federal de
PernambucoDepartment of GeneticsRecifePEBrazilDepartment of Genetics, Universidade
Federal de Pernambuco, Recife, PE, Brazil
| | - Daniela A. Marques
- Instituto AgronômicoInstituto AgronômicoCentro de P&D de Recursos Genéticos
VegetaisCampinasSPBrazilCentro de P&D de Recursos Genéticos
Vegetais, Instituto Agronômico, Campinas, SP, Brazil
| | - Ana Maria Benko-Iseppon
- Universidade Federal de
PernambucoUniversidade Federal de
PernambucoDepartment of GeneticsRecifePEBrazilDepartment of Genetics, Universidade
Federal de Pernambuco, Recife, PE, Brazil
| | - Ana Christina Brasileiro-Vidal
- Universidade Federal de
PernambucoUniversidade Federal de
PernambucoDepartment of GeneticsRecifePEBrazilDepartment of Genetics, Universidade
Federal de Pernambuco, Recife, PE, Brazil
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23
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Sochorová J, Garcia S, Gálvez F, Symonová R, Kovařík A. Evolutionary trends in animal ribosomal DNA loci: introduction to a new online database. Chromosoma 2018; 127:141-150. [PMID: 29192338 PMCID: PMC5818627 DOI: 10.1007/s00412-017-0651-8] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 11/24/2022]
Abstract
Ribosomal DNA (rDNA) loci encoding 5S and 45S (18S-5.8S-28S) rRNAs are important components of eukaryotic chromosomes. Here, we set up the animal rDNA database containing cytogenetic information about these loci in 1343 animal species (264 families) collected from 542 publications. The data are based on in situ hybridisation studies (both radioactive and fluorescent) carried out in major groups of vertebrates (fish, reptiles, amphibians, birds, and mammals) and invertebrates (mostly insects and mollusks). The database is accessible online at www.animalrdnadatabase.com . The median number of 45S and 5S sites was close to two per diploid chromosome set for both rDNAs despite large variation (1-74 for 5S and 1-54 for 45S sites). No significant correlation between the number of 5S and 45S rDNA loci was observed, suggesting that their distribution and amplification across the chromosomes follow independent evolutionary trajectories. Each group, irrespective of taxonomic classification, contained rDNA sites at any chromosome location. However, the distal and pericentromeric positions were the most prevalent (> 75% karyotypes) for 45S loci, while the position of 5S loci was more variable. We also examined potential relationships between molecular attributes of rDNA (homogenisation and expression) and cytogenetic parameters such as rDNA positions, chromosome number, and morphology.
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Affiliation(s)
- Jana Sochorová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-61265, Brno, Czech Republic
| | - Sònia Garcia
- Institut Botànic de Barcelona (IBB-CSIC-ICUB), Passeig del Migdia s/n, 08038, Barcelona, Catalonia, Spain
| | - Francisco Gálvez
- Bioscripts-Centro de Investigación y Desarrollo de Recursos Científicos, 41012, Sevilla, Andalusia, Spain
| | - Radka Symonová
- Faculty of Science, University of Hradec Kralove, Hradecka 1285, CZ-50003, Hradec Kralove, Czech Republic
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, CZ-61265, Brno, Czech Republic.
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24
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Yu S, Lemos B. The long-range interaction map of ribosomal DNA arrays. PLoS Genet 2018; 14:e1007258. [PMID: 29570716 PMCID: PMC5865718 DOI: 10.1371/journal.pgen.1007258] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Accepted: 02/15/2018] [Indexed: 11/28/2022] Open
Abstract
The repeated rDNA array gives rise to the nucleolus, an organelle that is central to cellular processes as varied as stress response, cell cycle regulation, RNA modification, cell metabolism, and genome stability. The rDNA array is also responsible for the production of more than 70% of all cellular RNAs (the ribosomal RNAs). The rRNAs are produced from two sets of loci: the 5S rDNA array resides exclusively on human chromosome 1 while the 45S rDNA arrays reside on the short arm of five human acrocentric chromosomes. These critical genome elements have remained unassembled and have been excluded from all Hi-C analyses to date. Here we built the first high resolution map of 5S and 45S rDNA array contacts with the rest of the genome combining over 15 billion Hi-C reads from several experiments. The data enabled sufficiently high coverage to map rDNA-genome interactions with 1MB resolution and identify rDNA-gene contacts. The map showed that the 5S and 45S arrays display preferential contact at common sites along the genome but are not themselves sufficiently close to yield 5S-45S Hi-C contacts. Ribosomal DNA contacts are enriched in segments of closed, repressed, and late replicating chromatin, as well as CTCF binding sites. Finally, we identified functional categories whose dispersed genes coalesced in proximity to the rDNA arrays or instead avoided proximity with the rDNA arrays. The observations further our understanding of the spatial localization of rDNA arrays and their contribution to the architecture of the cell nucleus.
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Affiliation(s)
- Shoukai Yu
- Program in Molecular and Integrative Physiological Sciences & Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, United States of America
| | - Bernardo Lemos
- Program in Molecular and Integrative Physiological Sciences & Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, MA, United States of America
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25
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Bolsheva NL, Melnikova NV, Kirov IV, Speranskaya AS, Krinitsina AA, Dmitriev AA, Belenikin MS, Krasnov GS, Lakunina VA, Snezhkina AV, Rozhmina TA, Samatadze TE, Yurkevich OY, Zoshchuk SA, Amosova АV, Kudryavtseva AV, Muravenko OV. Evolution of blue-flowered species of genus Linum based on high-throughput sequencing of ribosomal RNA genes. BMC Evol Biol 2017; 17:253. [PMID: 29297314 PMCID: PMC5751768 DOI: 10.1186/s12862-017-1105-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The species relationships within the genus Linum have already been studied several times by means of different molecular and phylogenetic approaches. Nevertheless, a number of ambiguities in phylogeny of Linum still remain unresolved. In particular, the species relationships within the sections Stellerolinum and Dasylinum need further clarification. Also, the question of independence of the species of the section Adenolinum still remains unanswered. Moreover, the relationships of L. narbonense and other species of the section Linum require further clarification. Additionally, the origin of tetraploid species of the section Linum (2n = 30) including the cultivated species L. usitatissimum has not been explored. The present study examines the phylogeny of blue-flowered species of Linum by comparisons of 5S rRNA gene sequences as well as ITS1 and ITS2 sequences of 35S rRNA genes. RESULTS High-throughput sequencing has been used for analysis of multicopy rRNA gene families. In addition to the molecular phylogenetic analysis, the number and chromosomal localization of 5S and 35S rDNA sites has been determined by FISH. Our findings confirm that L. stelleroides forms a basal branch from the clade of blue-flowered flaxes which is independent of the branch formed by species of the sect. Dasylinum. The current molecular phylogenetic approaches, the cytogenetic analysis as well as different genomic DNA fingerprinting methods applied previously did not discriminate certain species within the sect. Adenolinum. The allotetraploid cultivated species L. usitatissimum and its wild ancestor L. angustifolium (2n = 30) could originate either as the result of hybridization of two diploid species (2n = 16) related to the modern L. gandiflorum and L. decumbens, or hybridization of a diploid species (2n = 16) and a diploid ancestor of modern L. narbonense (2n = 14). CONCLUSIONS High-throughput sequencing of multicopy rRNA gene families allowed us to make several adjustments to the phylogeny of blue-flowered flax species and also reveal intra- and interspecific divergence of the rRNA gene sequences.
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Affiliation(s)
- Nadezhda L Bolsheva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Nataliya V Melnikova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ilya V Kirov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | | | | | - Alexey A Dmitriev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Maxim S Belenikin
- Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - George S Krasnov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Valentina A Lakunina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | | | - Tatiana A Rozhmina
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.,All-Russian Research Institute for Flax, Torzhok, Russia
| | - Tatiana E Samatadze
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Olga Yu Yurkevich
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Svyatoslav A Zoshchuk
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Аlexandra V Amosova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
| | - Anna V Kudryavtseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Olga V Muravenko
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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26
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Sergeeva EM, Shcherban AB, Adonina IG, Nesterov MA, Beletsky AV, Rakitin AL, Mardanov AV, Ravin NV, Salina EA. Fine organization of genomic regions tagged to the 5S rDNA locus of the bread wheat 5B chromosome. BMC PLANT BIOLOGY 2017; 17:183. [PMID: 29143604 PMCID: PMC5688495 DOI: 10.1186/s12870-017-1120-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
BACKGROUND The multigene family encoding the 5S rRNA, one of the most important structurally-functional part of the large ribosomal subunit, is an obligate component of all eukaryotic genomes. 5S rDNA has long been a favored target for cytological and phylogenetic studies due to the inherent peculiarities of its structural organization, such as the tandem arrays of repetitive units and their high interspecific divergence. The complex polyploid nature of the genome of bread wheat, Triticum aestivum, and the technically difficult task of sequencing clusters of tandem repeats mean that the detailed organization of extended genomic regions containing 5S rRNA genes remains unclear. This is despite the recent progress made in wheat genomic sequencing. Using pyrosequencing of BAC clones, in this work we studied the organization of two distinct 5S rDNA-tagged regions of the 5BS chromosome of bread wheat. RESULTS Three BAC-clones containing 5S rDNA were identified in the 5BS chromosome-specific BAC-library of Triticum aestivum. Using the results of pyrosequencing and assembling, we obtained six 5S rDNA- containing contigs with a total length of 140,417 bp, and two sets (pools) of individual 5S rDNA sequences belonging to separate, but closely located genomic regions on the 5BS chromosome. Both regions are characterized by the presence of approximately 70-80 copies of 5S rDNA, however, they are completely different in their structural organization. The first region contained highly diverged short-type 5S rDNA units that were disrupted by multiple insertions of transposable elements. The second region contained the more conserved long-type 5S rDNA, organized as a single tandem array. FISH using probes specific to both 5S rDNA unit types showed differences in the distribution and intensity of signals on the chromosomes of polyploid wheat species and their diploid progenitors. CONCLUSION A detailed structural organization of two closely located 5S rDNA-tagged genomic regions on the 5BS chromosome of bread wheat has been established. These two regions differ in the organization of both 5S rDNA and the neighboring sequences comprised of transposable elements, implying different modes of evolution for these regions.
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Affiliation(s)
- Ekaterina M Sergeeva
- The Federal Research Center "Institute of Cytology and Genetics SB RAS", Novosibirsk, Russia
| | - Andrey B Shcherban
- The Federal Research Center "Institute of Cytology and Genetics SB RAS", Novosibirsk, Russia.
| | - Irina G Adonina
- The Federal Research Center "Institute of Cytology and Genetics SB RAS", Novosibirsk, Russia
| | - Michail A Nesterov
- The Federal Research Center "Institute of Cytology and Genetics SB RAS", Novosibirsk, Russia
| | - Alexey V Beletsky
- The Federal Research Center "Fundamentals of Biotechnology RAS", Moscow, Russia
| | - Andrey L Rakitin
- The Federal Research Center "Fundamentals of Biotechnology RAS", Moscow, Russia
| | - Andrey V Mardanov
- The Federal Research Center "Fundamentals of Biotechnology RAS", Moscow, Russia
| | - Nikolai V Ravin
- The Federal Research Center "Fundamentals of Biotechnology RAS", Moscow, Russia
- Faculty of Biology, Moscow State University, Moscow, Russia
| | - Elena A Salina
- The Federal Research Center "Institute of Cytology and Genetics SB RAS", Novosibirsk, Russia
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27
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Higher-order organisation of extremely amplified, potentially functional and massively methylated 5S rDNA in European pikes (Esox sp.). BMC Genomics 2017; 18:391. [PMID: 28521734 PMCID: PMC5437419 DOI: 10.1186/s12864-017-3774-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 05/09/2017] [Indexed: 12/16/2022] Open
Abstract
Background Pikes represent an important genus (Esox) harbouring a pre-duplication karyotype (2n = 2x = 50) of economically important salmonid pseudopolyploids. Here, we have characterized the 5S ribosomal RNA genes (rDNA) in Esox lucius and its closely related E. cisalpinus using cytogenetic, molecular and genomic approaches. Intragenomic homogeneity and copy number estimation was carried out using Illumina reads. The higher-order structure of rDNA arrays was investigated by the analysis of long PacBio reads. Position of loci on chromosomes was determined by FISH. DNA methylation was analysed by methylation-sensitive restriction enzymes. Results The 5S rDNA loci occupy exclusively (peri)centromeric regions on 30–38 acrocentric chromosomes in both E. lucius and E. cisalpinus. The large number of loci is accompanied by extreme amplification of genes (>20,000 copies), which is to the best of our knowledge one of the highest copy number of rRNA genes in animals ever reported. Conserved secondary structures of predicted 5S rRNAs indicate that most of the amplified genes are potentially functional. Only few SNPs were found in genic regions indicating their high homogeneity while intergenic spacers were more heterogeneous and several families were identified. Analysis of 10–30 kb-long molecules sequenced by the PacBio technology (containing about 40% of total 5S rDNA) revealed that the vast majority (96%) of genes are organised in large several kilobase-long blocks. Dispersed genes or short tandems were less common (4%). The adjacent 5S blocks were directly linked, separated by intervening DNA and even inverted. The 5S units differing in the intergenic spacers formed both homogeneous and heterogeneous (mixed) blocks indicating variable degree of homogenisation between the loci. Both E. lucius and E. cisalpinus 5S rDNA was heavily methylated at CG dinucleotides. Conclusions Extreme amplification of 5S rRNA genes in the Esox genome occurred in the absence of significant pseudogenisation suggesting its recent origin and/or intensive homogenisation processes. The dense methylation of units indicates that powerful epigenetic mechanisms have evolved in this group of fish to silence amplified genes. We discuss how the higher-order repeat structures impact on homogenisation of 5S rDNA in the genome. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3774-7) contains supplementary material, which is available to authorized users.
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28
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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: 87] [Impact Index Per Article: 12.4] [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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29
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Yu S, Lemos B. A Portrait of Ribosomal DNA Contacts with Hi-C Reveals 5S and 45S rDNA Anchoring Points in the Folded Human Genome. Genome Biol Evol 2016; 8:3545-3558. [PMID: 27797956 PMCID: PMC5203791 DOI: 10.1093/gbe/evw257] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Ribosomal RNAs (rRNAs) account for >60% of all RNAs in eukaryotic cells and are encoded in the ribosomal DNA (rDNA) arrays. The rRNAs are produced from two sets of loci: the 5S rDNA array resides exclusively on human chromosome 1, whereas the 45S rDNA array resides on the short arm of five human acrocentric chromosomes. The 45S rDNA gives origin to the nucleolus, the nuclear organelle that is the site of ribosome biogenesis. Intriguingly, 5S and 45S rDNA arrays exhibit correlated copy number variation in lymphoblastoid cells (LCLs). Here we examined the genomic architecture and repeat content of the 5S and 45S rDNA arrays in multiple human genome assemblies (including PacBio MHAP assembly) and ascertained contacts between the rDNA arrays and the rest of the genome using Hi-C datasets from two human cell lines (erythroleukemia K562 and lymphoblastoid cells). Our analyses revealed that 5S and 45S arrays each have thousands of contacts in the folded genome, with rDNA-associated regions and genes dispersed across all chromosomes. The rDNA contact map displayed conserved and disparate features between two cell lines, and pointed to specific chromosomes, genomic regions, and genes with evidence of spatial proximity to the rDNA arrays; the data also showed a lack of direct physical interaction between the 5S and 45S rDNA arrays. Finally, the analysis identified an intriguing organization in the 5S array with Alu and 5S elements adjacent to one another and organized in opposite orientation along the array. Portraits of genome folding centered on the ribosomal DNA array could help understand the emergence of concerted variation, the control of 5S and 45S expression, as well as provide insights into an organelle that contributes to the spatial localization of human chromosomes during interphase.
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Affiliation(s)
- Shoukai Yu
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Bernardo Lemos
- Program in Molecular and Integrative Physiological Sciences, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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Milyutina IA, Ignatova EA, Ignatov MS, Goryunov DV, Troitsky AV. Structure of Intergenic Spacer IGS1 of Ribosomal Operon from Schistidium Mosses. BIOCHEMISTRY (MOSCOW) 2016; 80:1485-91. [PMID: 26615440 DOI: 10.1134/s0006297915110103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The structure of the intergenic spacer 1 (IGS1) of the ribosomal operon from 12 species of Schistidium mosses was studied. In the IGS1 sequences of these species, three conserved regions and two areas of GC- and A-enriched repeats were identified. All of the studied mosses have a conserved pyrimidine-enriched motif at the 5'-end of IGS1. Species-specific nucleotide substitutions and insertions were found in the conserved areas. The repeated units contain single nucleotide substitutions that make unique the majority of repeated units. The positions of such repeats in IGS1 are species-specific, but their number can vary within the species and among operons of the same specimen. The comparison of IGS1 sequences from the Schistidium species and from representatives of ten other moss genera revealed the presence of common conserved motifs with similar localization. Presumably, these motifs are elements of termination of the pre-rRNA transcription and processing of rRNA.
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Affiliation(s)
- I A Milyutina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia.
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Rosato M, Kovařík A, Garilleti R, Rosselló JA. Conserved Organisation of 45S rDNA Sites and rDNA Gene Copy Number among Major Clades of Early Land Plants. PLoS One 2016; 11:e0162544. [PMID: 27622766 PMCID: PMC5021289 DOI: 10.1371/journal.pone.0162544] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 08/24/2016] [Indexed: 11/26/2022] Open
Abstract
Genes encoding ribosomal RNA (rDNA) are universal key constituents of eukaryotic genomes, and the nuclear genome harbours hundreds to several thousand copies of each species. Knowledge about the number of rDNA loci and gene copy number provides information for comparative studies of organismal and molecular evolution at various phylogenetic levels. With the exception of seed plants, the range of 45S rDNA locus (encoding 18S, 5.8S and 26S rRNA) and gene copy number variation within key evolutionary plant groups is largely unknown. This is especially true for the three earliest land plant lineages Marchantiophyta (liverworts), Bryophyta (mosses), and Anthocerotophyta (hornworts). In this work, we report the extent of rDNA variation in early land plants, assessing the number of 45S rDNA loci and gene copy number in 106 species and 25 species, respectively, of mosses, liverworts and hornworts. Unexpectedly, the results show a narrow range of ribosomal locus variation (one or two 45S rDNA loci) and gene copies not present in vascular plant lineages, where a wide spectrum is recorded. Mutation analysis of whole genomic reads showed higher (3-fold) intragenomic heterogeneity of Marchantia polymorpha (Marchantiophyta) rDNA compared to Physcomitrella patens (Bryophyta) and two angiosperms (Arabidopsis thaliana and Nicotiana tomentosifomis) suggesting the presence of rDNA pseudogenes in its genome. No association between phylogenetic position, taxonomic adscription and the number of rDNA loci and gene copy number was found. Our results suggest a likely evolutionary rDNA stasis during land colonisation and diversification across 480 myr of bryophyte evolution. We hypothesise that strong selection forces may be acting against ribosomal gene locus amplification. Despite showing a predominant haploid phase and infrequent meiosis, overall rDNA homogeneity is not severely compromised in bryophytes.
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Affiliation(s)
- Marcela Rosato
- Jardín Botánico, ICBiBE-Unidad Asociada CSIC, Universidad de Valencia, c/Quart 80, E-46008, Valencia, Spain
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, CZ–61265, Czech Republic
| | - Ricardo Garilleti
- Departamento de Botánica, Facultad de Farmacia, Universidad de Valencia, E-46100, Burjassot, Spain
| | - Josep A. Rosselló
- Jardín Botánico, ICBiBE-Unidad Asociada CSIC, Universidad de Valencia, c/Quart 80, E-46008, Valencia, Spain
- Marimurtra Bot. Garden, Carl Faust Fdn., PO Box 112, E-17300, Blanes, Catalonia, Spain
- * E-mail:
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Rubio-Piña J, Quiroz-Moreno A, Sánchez-Teyer LF. A quantitative PCR approach for determining the ribosomal DNA copy number in the genome of Agave tequila Weber. ELECTRON J BIOTECHN 2016. [DOI: 10.1016/j.ejbt.2016.05.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Lewis LR, Liu Y, Rozzi R, Goffinet B. Infraspecific variation within and across complete organellar genomes and nuclear ribosomal repeats in a moss. Mol Phylogenet Evol 2015; 96:195-199. [PMID: 26724407 DOI: 10.1016/j.ympev.2015.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 12/03/2015] [Accepted: 12/09/2015] [Indexed: 10/22/2022]
Abstract
Bryophytes (mosses, liverworts, and hornworts) are diverse and ecologically and evolutionarily significant yet genome scale data sets and analyses remain extremely sparse relative to other groups of plants, and are completely lacking at the infraspecific level. By sequencing the complete organellar genomes and nuclear ribosomal repeat from seven patches of a South American sub-Antarctic neo-endemic non-model moss, we present the first characterization of infraspecific polymorphism within and across the three genomic compartments for a bryophyte. Diversity within patches is accounted for by both intraindividual and interindividual variation for the nuclear ribosomal repeat and plastid genome, respectively. This represents the most extensive infraspecific genomic dataset generated for an early land plant lineage thus far and provides insight into relative rates of substitution between organellar genomes, including high rates of nonsynonymous to synonymous substitutions.
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Affiliation(s)
- Lily R Lewis
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Rd., Storrs, CT 06269, USA; Omora Ethnobotanical Park, Institute of Ecology and Biodiversity, and Universidad de Magallanes, Puerto Williams, Antarctic Province, Chile.
| | - Yang Liu
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Rd., Storrs, CT 06269, USA.
| | - Ricardo Rozzi
- Department of Philosophy, University of North Texas, 1704 West Mulberry, Denton, TX 76201, USA; Omora Ethnobotanical Park, Institute of Ecology and Biodiversity, and Universidad de Magallanes, Puerto Williams, Antarctic Province, Chile.
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, University of Connecticut, 75 North Eagleville Rd., Storrs, CT 06269, USA.
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García-Souto D, Pasantes JJ. Molecular Cytogenetics in Digenean Parasites: Linked and Unlinked Major and 5S rDNAs, B Chromosomes and Karyotype Diversification. Cytogenet Genome Res 2015; 147:195-207. [DOI: 10.1159/000442504] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2015] [Indexed: 11/19/2022] Open
Abstract
Digenetic trematodes are the largest group of internal metazoan parasites, but their chromosomes are poorly studied. Although chromosome numbers and/or karyotypes are known for about 300 of the 18,000 described species, molecular cytogenetic knowledge is mostly limited to the mapping of telomeric sequences and/or of major rDNA clusters in 9 species. In this work we mapped major and 5S rDNA clusters and telomeric sequences in chromosomes of Bucephalus minimus, B. australis, Prosorhynchoides carvajali (Bucephaloidea), Monascus filiformis (Gymnophalloidea), Parorchis acanthus (Echinostomatoidea), Cryptocotyle lingua (Opisthorchioidea), Cercaria longicaudata, Monorchis parvus (Monorchioidea), Diphterostomum brusinae, and Bacciger bacciger (Microphalloidea). Whilst single major and minor rDNA clusters were mapped to different chromosome pairs in B. minimus and P. acanthus, overlapping signals were detected on a single chromosome pair in the remaining taxa. FISH experiments using major rDNA and telomeric probes clearly demonstrated the presence of highly stretched NORs in most of the digenean taxa analyzed. B chromosomes were detected in the B. bacciger samples hosted by Ruditapes decussatus. Although the cercariae specimens obtained from Donax trunculus, Tellina tenuis, and R. decussatus were in agreement with B. bacciger, their karyotypes showed striking morphological differences in agreement with the proposed assignation of these cercariae to different species of the genus Bacciger. Results are discussed in comparison with previous data on digenean chromosomes.
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Kim K, Lee SC, Lee J, Yu Y, Yang K, Choi BS, Koh HJ, Waminal NE, Choi HI, Kim NH, Jang W, Park HS, Lee J, Lee HO, Joh HJ, Lee HJ, Park JY, Perumal S, Jayakodi M, Lee YS, Kim B, Copetti D, Kim S, Kim S, Lim KB, Kim YD, Lee J, Cho KS, Park BS, Wing RA, Yang TJ. Complete chloroplast and ribosomal sequences for 30 accessions elucidate evolution of Oryza AA genome species. Sci Rep 2015; 5:15655. [PMID: 26506948 PMCID: PMC4623524 DOI: 10.1038/srep15655] [Citation(s) in RCA: 138] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 09/30/2015] [Indexed: 12/15/2022] Open
Abstract
Cytoplasmic chloroplast (cp) genomes and nuclear ribosomal DNA (nR) are the primary sequences used to understand plant diversity and evolution. We introduce a high-throughput method to simultaneously obtain complete cp and nR sequences using Illumina platform whole-genome sequence. We applied the method to 30 rice specimens belonging to nine Oryza species. Concurrent phylogenomic analysis using cp and nR of several of specimens of the same Oryza AA genome species provides insight into the evolution and domestication of cultivated rice, clarifying three ambiguous but important issues in the evolution of wild Oryza species. First, cp-based trees clearly classify each lineage but can be biased by inter-subspecies cross-hybridization events during speciation. Second, O. glumaepatula, a South American wild rice, includes two cytoplasm types, one of which is derived from a recent interspecies hybridization with O. longistminata. Third, the Australian O. rufipogan-type rice is a perennial form of O. meridionalis.
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Affiliation(s)
- Kyunghee Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea.,Phyzen Genome Institute, 501-1, Gwanak Century Tower, Kwanak-gu, Seoul, 151-836, Republic of Korea
| | - Sang-Choon Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Junki Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Yeisoo Yu
- Phyzen Genome Institute, 501-1, Gwanak Century Tower, Kwanak-gu, Seoul, 151-836, Republic of Korea.,Arizona Genomics Institute, School of Plant Sciences, The University of Arizona, Tucson, Arizona, 85721, USA
| | - Kiwoung Yang
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea.,Department of Horticulture, Sunchon National University, Suncheon, 540-950, Republic of Korea
| | - Beom-Soon Choi
- Phyzen Genome Institute, 501-1, Gwanak Century Tower, Kwanak-gu, Seoul, 151-836, Republic of Korea
| | - Hee-Jong Koh
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Nomar Espinosa Waminal
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Hong-Il Choi
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Nam-Hoon Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Woojong Jang
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Hyun-Seung Park
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Jonghoon Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Hyun Oh Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea.,Phyzen Genome Institute, 501-1, Gwanak Century Tower, Kwanak-gu, Seoul, 151-836, Republic of Korea
| | - Ho Jun Joh
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Hyeon Ju Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Jee Young Park
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Sampath Perumal
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Murukarthick Jayakodi
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Yun Sun Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Backki Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
| | - Dario Copetti
- Arizona Genomics Institute, School of Plant Sciences, The University of Arizona, Tucson, Arizona, 85721, USA
| | - Soonok Kim
- Biological and Genetic Resources Assessment Division, National Institute of Biological Resources, Incheon, 404-170, Republic of Korea
| | - Sunggil Kim
- Department of Plant Biotechnology, Biotechnology Research Institute, Chonnam National University, Gwangju, 500-757, Republic of Korea
| | - Ki-Byung Lim
- Department of Horticultural Science, Kyungpook National University, Daegu, 702-701, Republic of Korea
| | - Young-Dong Kim
- Department of Life Science, Hallym University, Chuncheon, Kangwon-do, 200-702, Republic of Korea
| | - Jungho Lee
- Green Plant Institute, #2-202 Biovalley, 89 Seoho-ro, Kwonseon-gu, Suwon, Republic of Korea
| | - Kwang-Su Cho
- Highland Agriculture Research Institute, National Institute of Crop Science, Rural Development Administration, Pyeongchang-gun, Kangwon-do, 232-955, Republic of Korea
| | - Beom-Seok Park
- Department of Agricultural Biotechnology, National Academy of Agricultural Science, Rural Development Administration, Jeonju, 560-500, Republic of Korea
| | - Rod A Wing
- Arizona Genomics Institute, School of Plant Sciences, The University of Arizona, Tucson, Arizona, 85721, USA
| | - Tae-Jin Yang
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea
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Hans M, Charpentier M, Huch V, Jauch J, Bruhn T, Bringmann G, Quandt D. Stereoisomeric Composition of Natural Myrtucommulone A. JOURNAL OF NATURAL PRODUCTS 2015; 78:2381-2389. [PMID: 26457652 DOI: 10.1021/acs.jnatprod.5b00358] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Myrtucommulone A (MC A) (1), isolated from Myrtus communis (myrtle), shows the same pharmacological activity for inhibition of inflammation and induction of apoptosis as synthetic MC A, which consists of three stereoisomers, i.e., two enantiomers and one meso form. This led to the question of whether the natural MC A is a pure stereoisomer or a mixture of stereoisomers. The specific rotation and electronic circular dichroism (ECD) data of natural MC A (1) as well as of a pentacyclic derivative 4 revealed that naturally occurring MC A (1) consists of the racemate and the meso form in a 1:1 ratio. A probable precursor of MC A (1), nor-semimyrtucommulone (5), was also isolated from myrtle as a racemate. The absolute configurations of the enantiomers of 1 and 5 were determined using a combination of experimental and quantum-chemical calculated ECD spectra.
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Affiliation(s)
- Marcus Hans
- Institute of Organic Chemistry, Saarland University , Campus C 4.2, 66123 Saarbrücken, Germany
| | - Maël Charpentier
- Institute of Organic Chemistry, Saarland University , Campus C 4.2, 66123 Saarbrücken, Germany
| | - Volker Huch
- Institute of Inorganic Chemistry, Saarland University , Campus C 4.1, 66123 Saarbrücken, Germany
| | - Johann Jauch
- Institute of Organic Chemistry, Saarland University , Campus C 4.2, 66123 Saarbrücken, Germany
| | - Torsten Bruhn
- Institute of Organic Chemistry, University of Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Gerhard Bringmann
- Institute of Organic Chemistry, University of Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Dietmar Quandt
- Nees-Institute for Biodiversity of Plants, University of Bonn , Meckenheimer Allee 170, 53115 Bonn, Germany
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Kim K, Lee SC, Lee J, Lee HO, Joh HJ, Kim NH, Park HS, Yang TJ. Comprehensive Survey of Genetic Diversity in Chloroplast Genomes and 45S nrDNAs within Panax ginseng Species. PLoS One 2015; 10:e0117159. [PMID: 26061692 PMCID: PMC4465672 DOI: 10.1371/journal.pone.0117159] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 04/28/2015] [Indexed: 11/18/2022] Open
Abstract
We report complete sequences of chloroplast (cp) genome and 45S nuclear ribosomal DNA (45S nrDNA) for 11 Panax ginseng cultivars. We have obtained complete sequences of cp and 45S nrDNA, the representative barcoding target sequences for cytoplasm and nuclear genome, respectively, based on low coverage NGS sequence of each cultivar. The cp genomes sizes ranged from 156,241 to 156,425 bp and the major size variation was derived from differences in copy number of tandem repeats in the ycf1 gene and in the intergenic regions of rps16-trnUUG and rpl32-trnUAG. The complete 45S nrDNA unit sequences were 11,091 bp, representing a consensus single transcriptional unit with an intergenic spacer region. Comparative analysis of these sequences as well as those previously reported for three Chinese accessions identified very rare but unique polymorphism in the cp genome within P. ginseng cultivars. There were 12 intra-species polymorphisms (six SNPs and six InDels) among 14 cultivars. We also identified five SNPs from 45S nrDNA of 11 Korean ginseng cultivars. From the 17 unique informative polymorphic sites, we developed six reliable markers for analysis of ginseng diversity and cultivar authentication.
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Affiliation(s)
- Kyunghee Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
- Phyzen Genomics Institute, 501–1, Gwanak Century Tower, Gwanak-gu, Seoul, 151–836, Republic of Korea
| | - Sang-Choon Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
| | - Junki Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
| | - Hyun Oh Lee
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
| | - Ho Jun Joh
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
| | - Nam-Hoon Kim
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
| | - Hyun-Seung Park
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
| | - Tae-Jin Yang
- Department of Plant Science, Plant Genomics and Breeding Institute, and Research Institute of Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151–921, Republic of Korea
- * E-mail:
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Garcia S, Gálvez F, Gras A, Kovařík A, Garnatje T. Plant rDNA database: update and new features. DATABASE-THE JOURNAL OF BIOLOGICAL DATABASES AND CURATION 2014; 2014:bau063. [PMID: 24980131 PMCID: PMC4075780 DOI: 10.1093/database/bau063] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The Plant rDNA database (www.plantrdnadatabase.com) is an open access online resource providing detailed information on numbers, structures and positions of 5S and 18S-5.8S-26S (35S) ribosomal DNA loci. The data have been obtained from >600 publications on plant molecular cytogenetics, mostly based on fluorescent in situ hybridization (FISH). This edition of the database contains information on 1609 species derived from 2839 records, which means an expansion of 55.76 and 94.45%, respectively. It holds the data for angiosperms, gymnosperms, bryophytes and pteridophytes available as of June 2013. Information from publications reporting data for a single rDNA (either 5S or 35S alone) and annotation regarding transcriptional activity of 35S loci now appears in the database. Preliminary analyses suggest greater variability in the number of rDNA loci in gymnosperms than in angiosperms. New applications provide ideograms of the species showing the positions of rDNA loci as well as a visual representation of their genome sizes. We have also introduced other features to boost the usability of the Web interface, such as an application for convenient data export and a new section with rDNA–FISH-related information (mostly detailing protocols and reagents). In addition, we upgraded and/or proofread tabs and links and modified the website for a more dynamic appearance. This manuscript provides a synopsis of these changes and developments. Database URL: http://www.plantrdnadatabase.com
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Affiliation(s)
- Sònia Garcia
- Laboratori de Botànica-Unitat associada CSIC, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, 08028 Catalonia, Spain, BioScripts - Centro de Investigación y Desarrollo de Recursos Científicos, Sevilla, 41012 Andalusia, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic. Brno, CZ-612 65, Czech Republic and Institut Botànic de Barcelona (IBB-CSIC-ICUB). Barcelona, 08038 Catalonia, Spain
| | - Francisco Gálvez
- Laboratori de Botànica-Unitat associada CSIC, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, 08028 Catalonia, Spain, BioScripts - Centro de Investigación y Desarrollo de Recursos Científicos, Sevilla, 41012 Andalusia, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic. Brno, CZ-612 65, Czech Republic and Institut Botànic de Barcelona (IBB-CSIC-ICUB). Barcelona, 08038 Catalonia, Spain
| | - Airy Gras
- Laboratori de Botànica-Unitat associada CSIC, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, 08028 Catalonia, Spain, BioScripts - Centro de Investigación y Desarrollo de Recursos Científicos, Sevilla, 41012 Andalusia, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic. Brno, CZ-612 65, Czech Republic and Institut Botànic de Barcelona (IBB-CSIC-ICUB). Barcelona, 08038 Catalonia, Spain
| | - Aleš Kovařík
- Laboratori de Botànica-Unitat associada CSIC, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, 08028 Catalonia, Spain, BioScripts - Centro de Investigación y Desarrollo de Recursos Científicos, Sevilla, 41012 Andalusia, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic. Brno, CZ-612 65, Czech Republic and Institut Botànic de Barcelona (IBB-CSIC-ICUB). Barcelona, 08038 Catalonia, Spain
| | - Teresa Garnatje
- Laboratori de Botànica-Unitat associada CSIC, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, 08028 Catalonia, Spain, BioScripts - Centro de Investigación y Desarrollo de Recursos Científicos, Sevilla, 41012 Andalusia, Spain, Institute of Biophysics, Academy of Sciences of the Czech Republic. Brno, CZ-612 65, Czech Republic and Institut Botànic de Barcelona (IBB-CSIC-ICUB). Barcelona, 08038 Catalonia, Spain
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Evolutionary dynamics of rDNA clusters in chromosomes of five clam species belonging to the family Veneridae (Mollusca, Bivalvia). BIOMED RESEARCH INTERNATIONAL 2014; 2014:754012. [PMID: 24967400 PMCID: PMC4054880 DOI: 10.1155/2014/754012] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 04/23/2014] [Accepted: 04/25/2014] [Indexed: 11/26/2022]
Abstract
The chromosomal changes accompanying bivalve evolution are an area about which few reports have been published. To improve our understanding on chromosome evolution in Veneridae, ribosomal RNA gene clusters were mapped by fluorescent in situ hybridization (FISH) to chromosomes of five species of venerid clams (Venerupis corrugata, Ruditapes philippinarum, Ruditapes decussatus, Dosinia exoleta, and Venus verrucosa). The results were anchored to the most comprehensive molecular phylogenetic tree currently available for Veneridae. While a single major rDNA cluster was found in each of the five species, the number of 5S rDNA clusters showed high interspecies variation. Major rDNA was either subterminal to the short arms or intercalary to the long arms of metacentric or submetacentric chromosomes, whereas minor rDNA signals showed higher variability. Major and minor rDNAs map to different chromosome pairs in all species, but in R. decussatus one of the minor rDNA gene clusters and the major rDNA cluster were located in the same position on a single chromosome pair. This interspersion of both sequences was confirmed by fiber FISH. Telomeric signals appeared at both ends of every chromosome in all species. FISH mapping data are discussed in relation to the molecular phylogenetic trees currently available for Veneridae.
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40
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Rebordinos L, Cross I, Merlo A. High evolutionary dynamism in 5S rDNA of fish: state of the art. Cytogenet Genome Res 2013; 141:103-13. [PMID: 24080995 DOI: 10.1159/000354871] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The 5S ribosomal DNA (rDNA) consists of one transcriptional unit of about 120 base pairs, which is separated from the next unit by a non-transcribed spacer (NTS). The coding sequence and the NTS together form a repeat unit which can be found in hundreds to thousands of copies tandemly repeated in the genomes. The NTS regions seem to be subject to rapid evolution. The first general model of evolution of these multigene families was referred to as divergent evolution, based on studies using hemoglobin and myoglobin as model systems. Later studies showed that nucleotide sequences of different multigene family members are more closely related within species than between species. This observation led to a new model of multigene family evolution, termed concerted evolution. Another model of evolution, named the birth-and-death model, has been found to be more suitable to explain the long-term evolution of these multigene families. According to this model, new genes originate by successive duplications, and these new genes are either maintained for a long time or are lost, or else degenerate into pseudogenes. In this review we describe different sources of variability in the 5S rDNA genes observed in several distinct fish species. This variability is mainly referred to NTSs and includes the presence of other multigene families (mainly LINEs, SINEs, non-LTR retrotransposons, and U snRNA families). Different types of microsatellites have also been found to contribute to the increase of variability in this region. Our recent results suggest that horizontal transfer contributes to the increase of diversity in the NTSs of some species. Variability in the 5S rDNA coding region affecting the stability of the structure, but without effects on the function of the 5S rRNA, is also described. Retrotransposons seem to be responsible for the high dynamism of 5S rDNA, while microsatellites acting as recombination hot spots could stabilize a wide variety of unusual DNA structures, affecting DNA replication and enhancing or decreasing promoter activity in gene expression. The relationship between the high variability found at molecular level and the low variability found at chromosomal level is also discussed.
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Affiliation(s)
- L Rebordinos
- Area de Genética, Facultad de Ciencias del Mar y Ambientales, CEI-Mar, Universidad de Cádiz, Puerto Real, Spain
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41
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Beauparlant MA, Drouin G. Multiple independent insertions of 5S rRNA genes in the spliced-leader gene family of trypanosome species. Curr Genet 2013; 60:17-24. [DOI: 10.1007/s00294-013-0404-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 08/16/2013] [Accepted: 08/22/2013] [Indexed: 11/21/2022]
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42
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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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Mahelka V, Kopecký D, Baum BR. Contrasting Patterns of Evolution of 45S and 5S rDNA Families Uncover New Aspects in the Genome Constitution of the Agronomically Important Grass Thinopyrum intermedium (Triticeae). Mol Biol Evol 2013; 30:2065-86. [DOI: 10.1093/molbev/mst106] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
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Dancing together and separate again: gymnosperms exhibit frequent changes of fundamental 5S and 35S rRNA gene (rDNA) organisation. Heredity (Edinb) 2013; 111:23-33. [PMID: 23512008 PMCID: PMC3692318 DOI: 10.1038/hdy.2013.11] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In higher eukaryotes, the 5S rRNA genes occur in tandem units and are arranged either
separately (S-type arrangement) or linked to other repeated genes, in most cases to rDNA
locus encoding 18S–5.8S–26S genes (L-type arrangement). Here we used Southern
blot hybridisation, PCR and sequencing approaches to analyse genomic organisation of rRNA
genes in all large gymnosperm groups, including Coniferales, Ginkgoales, Gnetales and
Cycadales. The data are provided for 27 species (21 genera). The 5S units linked to the
35S rDNA units occur in some but not all Gnetales, Coniferales and in Ginkgo
(∼30% of the species analysed), while the remaining exhibit separate
organisation. The linked 5S rRNA genes may occur as single-copy insertions or as short
tandems embedded in the 26S–18S rDNA intergenic spacer (IGS). The 5S transcript may
be encoded by the same (Ginkgo, Ephedra) or opposite
(Podocarpus) DNA strand as the 18S–5.8S–26S genes. In addition,
pseudogenised 5S copies were also found in some IGS types. Both L- and S-type units have
been largely homogenised across the genomes. Phylogenetic relationships based on the
comparison of 5S coding sequences suggest that the 5S genes independently inserted IGS at
least three times in the course of gymnosperm evolution. Frequent transpositions and
rearrangements of basic units indicate relatively relaxed selection pressures imposed on
genomic organisation of 5S genes in plants.
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45
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Organellar genome, nuclear ribosomal DNA repeat unit, and microsatellites isolated from a small-scale of 454 GS FLX sequencing on two mosses. Mol Phylogenet Evol 2013; 66:1089-94. [DOI: 10.1016/j.ympev.2012.12.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 11/30/2012] [Accepted: 12/06/2012] [Indexed: 11/19/2022]
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Matsunaga S, Katagiri Y, Nagashima Y, Sugiyama T, Hasegawa J, Hayashi K, Sakamoto T. New insights into the dynamics of plant cell nuclei and chromosomes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 305:253-301. [PMID: 23890384 DOI: 10.1016/b978-0-12-407695-2.00006-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plant lamin-like protein NMCP/AtLINC and orthologues of the SUN-KASH complex across the nuclear envelope (NE) show the universality of nuclear structure in eukaryotes. However, depletion of components in the connection complex of the NE in plants does not induce severe defects, unlike in animals. Appearance of the Rabl configuration is not dependent on genome size in plant species. Topoisomerase II and condensin II are not essential for plant chromosome condensation. Plant endoreduplication shares several common characteristics with animals, including involvement of cyclin-dependent kinases and E2F transcription factors. Recent finding regarding endomitosis regulator GIG1 shed light on the suppression mechanism of endomitosis in plants. The robustness of plants, compared with animals, is reflected in their genome redundancy. Spatiotemporal functional analyses using chromophore-assisted light inactivation, super-resolution microscopy, and 4D (3D plus time) imaging will reveal new insights into plant nuclear and chromosomal dynamics.
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Affiliation(s)
- Sachihiro Matsunaga
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan.
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Drouin G, Tsang C. 5S rRNA Gene Arrangements in Protists: A Case of Nonadaptive Evolution. J Mol Evol 2012; 74:342-51. [DOI: 10.1007/s00239-012-9512-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 06/25/2012] [Indexed: 12/30/2022]
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Garcia S, Crhák Khaitová L, Kovařík A. Expression of 5 S rRNA genes linked to 35 S rDNA in plants, their epigenetic modification and regulatory element divergence. BMC PLANT BIOLOGY 2012; 12:95. [PMID: 22716941 PMCID: PMC3409069 DOI: 10.1186/1471-2229-12-95] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 06/20/2012] [Indexed: 05/09/2023]
Abstract
BACKGROUND In plants, the 5 S rRNA genes usually occur as separate tandems (S-type arrangement) or, less commonly, linked to 35 S rDNA units (L-type). The activity of linked genes remains unknown so far. We studied the homogeneity and expression of 5 S genes in several species from family Asteraceae known to contain linked 35 S-5 S units. Additionally, their methylation status was determined using bisulfite sequencing. Fluorescence in situ hybridization was applied to reveal the sub-nuclear positions of rDNA arrays. RESULTS We found that homogenization of L-type units went to completion in most (4/6) but not all species. Two species contained major L-type and minor S-type units (termed L(s)-type). The linked genes dominate 5 S rDNA expression while the separate tandems do not seem to be expressed. Members of tribe Anthemideae evolved functional variants of the polymerase III promoter in which a residing C-box element differs from the canonical angiosperm motif by as much as 30%. On this basis, a more relaxed consensus sequence of a plant C-box: (5'-RGSWTGGGTG-3') is proposed. The 5 S paralogs display heavy DNA methylation similarly as to their unlinked counterparts. FISH revealed the close association of 35 S-5 S arrays with nucleolar periphery indicating that transcription of 5 S genes may occur in this territory. CONCLUSIONS We show that the unusual linked arrangement of 5 S genes, occurring in several plant species, is fully compatible with their expression and functionality. This extraordinary 5 S gene dynamics is manifested at different levels, such as variation in intrachromosomal positions, unit structure, epigenetic modification and considerable divergence of regulatory motifs.
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MESH Headings
- Animals
- Asteraceae/chemistry
- Asteraceae/genetics
- Asteraceae/metabolism
- Base Sequence
- Consensus Sequence
- DNA Methylation
- DNA, Plant/chemistry
- DNA, Plant/genetics
- DNA, Plant/metabolism
- Epigenesis, Genetic
- Evolution, Molecular
- Gene Expression Regulation, Plant
- Molecular Sequence Data
- Promoter Regions, Genetic
- RNA, Ribosomal/chemistry
- RNA, Ribosomal/genetics
- RNA, Ribosomal/metabolism
- Regulatory Sequences, Nucleic Acid
- Response Elements
- Sequence Alignment
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Affiliation(s)
- Sònia Garcia
- Laboratori de Botànica, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s. n., Barcelona, Catalonia, 08028, Spain
| | - Lucie Crhák Khaitová
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, Brno, CZ-6125, Czech Republic
| | - Aleš Kovařík
- Institute of Biophysics, Academy of Sciences of the Czech Republic, Královopolská 135, Brno, CZ-6125, Czech Republic
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Early evolutionary colocalization of the nuclear ribosomal 5S and 45S gene families in seed plants: evidence from the living fossil gymnosperm Ginkgo biloba. Heredity (Edinb) 2012; 108:640-6. [PMID: 22354111 DOI: 10.1038/hdy.2012.2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In seed plants, the colocalization of the 5S loci within the intergenic spacer (IGS) of the nuclear 45S tandem units is restricted to the phylogenetically derived Asteraceae family. However, fluorescent in situ hybridization (FISH) colocalization of both multigene families has also been observed in other unrelated seed plant lineages. Previous work has identified colocalization of 45S and 5S loci in Ginkgo biloba using FISH, but these observations have not been confirmed recently by sequencing a 1.8 kb IGS. In this work, we report the presence of the 45S-5S linkage in G. biloba, suggesting that in seed plants the molecular events leading to the restructuring of the ribosomal loci are much older than estimated previously. We obtained a 6.0 kb IGS fragment showing structural features of functional sequences, and a single copy of the 5S gene was inserted in the same direction of transcription as the ribosomal RNA genes. We also obtained a 1.8 kb IGS that was a truncate variant of the 6.0 kb IGS lacking the 5S gene. Several lines of evidence strongly suggest that the 1.8 kb variants are pseudogenes that are present exclusively on the satellite chromosomes bearing the 45S-5S genes. The presence of ribosomal IGS pseudogenes best reconciles contradictory results concerning the presence or absence of the 45S-5S linkage in Ginkgo. Our finding that both ribosomal gene families have been unified to a single 45S-5S unit in Ginkgo indicates that an accurate reassessment of the organization of rDNA genes in basal seed plants is necessary.
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50
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Layat E, Sáez-Vásquez J, Tourmente S. Regulation of Pol I-transcribed 45S rDNA and Pol III-transcribed 5S rDNA in Arabidopsis. PLANT & CELL PHYSIOLOGY 2012; 53:267-76. [PMID: 22173098 DOI: 10.1093/pcp/pcr177] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The 18S, 5.8S and 25S rRNAs, which result from the 45S precursor, together with 5S rRNAs, are central components of the ribosome. The integration of one molecule of each rRNA per ribosome necessitates an elaborate coordination between transcriptions of the two ribosomal DNA (rDNA) families. Even though 5S rDNA is transcribed by RNA polymerase III and 45S rDNA by RNA polymerase I, the two rDNA families present certain similarities in their transcriptional regulation. This review aims to compare 5S and 45S rRNA genes in the plant model Arabidopsis thaliana in terms of organization, transcription and regulation, and draws parallels between the two rDNA families.
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Affiliation(s)
- Elodie Layat
- CNRS, UMR 6247 GReD, Clermont Université, INSERM U931, Aubière, France
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