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Mano NA, Shaikh MA, Widhalm JR, Yoo CY, Mickelbart MV. Transcriptional repression of GTL1 under water-deficit stress promotes anthocyanin biosynthesis to enhance drought tolerance. PLANT DIRECT 2024; 8:e594. [PMID: 38799417 PMCID: PMC11117050 DOI: 10.1002/pld3.594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2024] [Accepted: 04/29/2024] [Indexed: 05/29/2024]
Abstract
The transcription factor GT2-LIKE 1 (GTL1) has been implicated in orchestrating a transcriptional network of diverse physiological, biochemical, and developmental processes. In response to water-limiting conditions, GTL1 is a negative regulator of stomatal development, but its potential rolein other water-deficit responses is unknown. We hypothesized that GTL1 regulates transcriptome changes associated with drought tolerance over leaf developmental stages. To test the hypothesis, gene expression was profiled by RNA-seq analysis in emerging and expanding leaves of wild-type and a drought-tolerant gtl1-4 knockout mutant under well-watered and water-deficit conditions. Our comparative analysis of genotype-treatment combinations within leaf developmental age identified 459 and 1073 differentially expressed genes in emerging and expanding leaves, respectively, as water-deficit responsive GTL1-regulated genes. Transcriptional profiling identified a potential role of GTL1 in two important pathways previously linked to drought tolerance: flavonoid and polyamine biosynthesis. In expanding leaves, negative regulation of GTL1 under water-deficit conditions promotes biosynthesis of flavonoids and anthocyanins that may contribute to drought tolerance. Quantification of polyamines did not support a role for GTL1 in these drought-responsive pathways, but this is likely due to the complex nature of polyamine synthesis and turnover. Our global transcriptome analysis suggests that transcriptional repression of GTL1 by water deficit allows plants to activate diverse pathways that collectively contribute to drought tolerance.
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Affiliation(s)
- Noel Anthony Mano
- Department of Botany and Plant PathologyPurdue UniversityWest LafayetteIndianaUSA
- Center for Plant BiologyPurdue UniversityWest LafayetteIndianaUSA
- Department of Biological and Environmental SciencesHeidelberg UniversityTiffinOhioUSA
- Present address:
School of Biological SciencesThe University of UtahSalt Lake CityUtahUSA
| | - Mearaj A. Shaikh
- Center for Plant BiologyPurdue UniversityWest LafayetteIndianaUSA
- Department of Horticulture and Landscape ArchitecturePurdue UniversityWest LafayetteIndianaUSA
| | - Joshua R. Widhalm
- Center for Plant BiologyPurdue UniversityWest LafayetteIndianaUSA
- Department of Horticulture and Landscape ArchitecturePurdue UniversityWest LafayetteIndianaUSA
| | - Chan Yul Yoo
- Present address:
School of Biological SciencesThe University of UtahSalt Lake CityUtahUSA
| | - Michael V. Mickelbart
- Department of Botany and Plant PathologyPurdue UniversityWest LafayetteIndianaUSA
- Center for Plant BiologyPurdue UniversityWest LafayetteIndianaUSA
- Department of Horticulture and Landscape ArchitecturePurdue UniversityWest LafayetteIndianaUSA
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2
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Hao Q, Liu M, Daulatabad SV, Gaffari S, Song YJ, Srivastava R, Bhaskar S, Moitra A, Mangan H, Tseng E, Gilmore RB, Frier SM, Chen X, Wang C, Huang S, Chamberlain S, Jin H, Korlach J, McStay B, Sinha S, Janga SC, Prasanth SG, Prasanth KV. Monoallelically expressed noncoding RNAs form nucleolar territories on NOR-containing chromosomes and regulate rRNA expression. eLife 2024; 13:e80684. [PMID: 38240312 PMCID: PMC10852677 DOI: 10.7554/elife.80684] [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: 05/31/2022] [Accepted: 01/18/2024] [Indexed: 02/07/2024] Open
Abstract
Out of the several hundred copies of rRNA genes arranged in the nucleolar organizing regions (NOR) of the five human acrocentric chromosomes, ~50% remain transcriptionally inactive. NOR-associated sequences and epigenetic modifications contribute to the differential expression of rRNAs. However, the mechanism(s) controlling the dosage of active versus inactive rRNA genes within each NOR in mammals is yet to be determined. We have discovered a family of ncRNAs, SNULs (Single NUcleolus Localized RNA), which form constrained sub-nucleolar territories on individual NORs and influence rRNA expression. Individual members of the SNULs monoallelically associate with specific NOR-containing chromosomes. SNULs share sequence similarity to pre-rRNA and localize in the sub-nucleolar compartment with pre-rRNA. Finally, SNULs control rRNA expression by influencing pre-rRNA sorting to the DFC compartment and pre-rRNA processing. Our study discovered a novel class of ncRNAs influencing rRNA expression by forming constrained nucleolar territories on individual NORs.
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Affiliation(s)
- Qinyu Hao
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Minxue Liu
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Swapna Vidhur Daulatabad
- Department of BioHealth Informatics, School of Informatics and Computing, IUPUIIndianapolisUnited States
| | - Saba Gaffari
- Department of Computer Science, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - You Jin Song
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Rajneesh Srivastava
- Department of BioHealth Informatics, School of Informatics and Computing, IUPUIIndianapolisUnited States
| | - Shivang Bhaskar
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Anurupa Moitra
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Hazel Mangan
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland GalwayGalwayIreland
| | | | - Rachel B Gilmore
- Department of Genetics and Genome Sciences, University of Connecticut School of MedicineFarmingtonUnited States
| | | | - Xin Chen
- Department of Biophysics and Quantitative Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Chengliang Wang
- Department of Biochemistry, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Sui Huang
- Department of Cell and Molecular Biology, Northwestern UniversityChicagoUnited States
| | - Stormy Chamberlain
- Department of Genetics and Genome Sciences, University of Connecticut School of MedicineFarmingtonUnited States
| | - Hong Jin
- Department of Biophysics and Quantitative Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
- Department of Biochemistry, University of Illinois at Urbana-ChampaignUrbanaUnited States
- Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | | | - Brian McStay
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland GalwayGalwayIreland
| | - Saurabh Sinha
- Department of Computer Science, University of Illinois at Urbana-ChampaignUrbanaUnited States
- Department of Biomedical Engineering, Georgia TechAtlantaUnited States
| | - Sarath Chandra Janga
- Department of BioHealth Informatics, School of Informatics and Computing, IUPUIIndianapolisUnited States
| | - Supriya G Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
- Cancer Center at Illinois, University of Illinois at Urbana-ChampaignUrbanaUnited States
| | - Kannanganattu V Prasanth
- Department of Cell and Developmental Biology, University of Illinois at Urbana-ChampaignUrbanaUnited States
- Cancer Center at Illinois, University of Illinois at Urbana-ChampaignUrbanaUnited States
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3
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Fultz D, McKinlay A, Enganti R, Pikaard CS. Sequence and epigenetic landscapes of active and silent nucleolus organizer regions in Arabidopsis. SCIENCE ADVANCES 2023; 9:eadj4509. [PMID: 37910609 PMCID: PMC10619934 DOI: 10.1126/sciadv.adj4509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Accepted: 09/27/2023] [Indexed: 11/03/2023]
Abstract
Arabidopsis thaliana has two ribosomal RNA (rRNA) gene loci, nucleolus organizer regions NOR2 and NOR4, whose complete sequences are missing in current genome assemblies. Ultralong DNA sequences assembled using an unconventional approach yielded ~5.5- and 3.9-Mbp sequences for NOR2 and NOR4 in the reference strain, Col-0. The distinct rRNA gene subtype compositions of the NORs enabled the positional mapping of their active and inactive regions, using RNA sequencing to identify subtype-specific transcripts and DNA sequencing to identify subtypes associated with flow-sorted nucleoli. Comparisons of wild-type and silencing-defective plants revealed that most rRNA gene activity occurs in the central region of NOR4, whereas most, but not all, genes of NOR2 are epigenetically silenced. Intervals of low CG and CHG methylation overlap regions where gene activity and gene subtype homogenization are high. Collectively, the data reveal the genetic and epigenetic landscapes underlying nucleolar dominance (differential NOR activity) and implicate transcription as a driver of rRNA gene concerted evolution.
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Affiliation(s)
- Dalen Fultz
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Anastasia McKinlay
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Ramya Enganti
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
| | - Craig S. Pikaard
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, USA
- Department of Biology, Indiana University, Bloomington, IN, USA
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, USA
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4
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Murphy PJ, Berger F. The chromatin source-sink hypothesis: a shared mode of chromatin-mediated regulations. Development 2023; 150:dev201989. [PMID: 38771301 PMCID: PMC10629678 DOI: 10.1242/dev.201989] [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: 05/13/2023] [Accepted: 09/12/2023] [Indexed: 11/05/2023]
Abstract
We propose that several chromatin-mediated regulatory processes are dominated by source-sink relationships in which factors operate as 'sources' to produce or provide a resource and compete with each other to occupy separate 'sinks'. In this model, large portions of genomic DNA operate as 'sinks', which are filled by 'sources', such as available histone variants, covalent modifications to histones, the readers of these modifications and non-coding RNAs. Competing occupation for the sinks by different sources leads to distinct states of genomic equilibrium in differentiated cells. During dynamic developmental events, such as sexual reproduction, we propose that dramatic and rapid reconfiguration of source-sink relationships modifies chromatin states. We envision that re-routing of sources could occur by altering the dimensions of the sink, by reconfiguration of existing sink occupation or by varying the size of the source, providing a central mechanism to explain a plethora of epigenetic phenomena, which contribute to phenotypic variegation, zygotic genome activation and nucleolar dominance.
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Affiliation(s)
- Patrick J. Murphy
- University of Rochester, Department of Biomedical Genetics and Department of Biology, 601 Elmwood Ave., Rochester NY 14620, USA
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter; Dr. Bohr-Gasse 3, 1030 Vienna, Austria
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Delorme-Hinoux V, Mbodj A, Brando S, De Bures A, Llauro C, Covato F, Garrigue J, Guisset C, Borrut J, Mirouze M, Reichheld JP, Sáez-Vásquez J. 45S rDNA Diversity In Natura as One Step towards Ribosomal Heterogeneity in Arabidopsis thaliana. PLANTS (BASEL, SWITZERLAND) 2023; 12:2722. [PMID: 37514338 PMCID: PMC10386311 DOI: 10.3390/plants12142722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023]
Abstract
The keystone of ribosome biogenesis is the transcription of 45S rDNA. The Arabidopsis thaliana genome contains hundreds of 45S rDNA units; however, they are not all transcribed. Notably, 45S rDNA units contain insertions/deletions revealing the existence of heterogeneous rRNA genes and, likely, heterogeneous ribosomes for rRNAs. In order to obtain an overall picture of 45S rDNA diversity sustaining the synthesis of rRNAs and, subsequently, of ribosomes in natura, we took advantage of 320 new occurrences of Arabidopsis thaliana as a metapopulation named At66, sampled from 0 to 1900 m of altitude in the eastern Pyrenees in France. We found that the 45S rDNA copy number is very dynamic in natura and identified new genotypes for both 5' and 3' External Transcribed Spacers (ETS). Interestingly, the highest 5'ETS genotype diversity is found in altitude while the highest 3'ETS genotype diversity is found at sea level. Structural analysis of 45S rDNA also shows conservation in natura of specific 5'ETS and 3'ETS sequences/features required to control rDNA expression and the processing of rRNAs. In conclusion, At66 is a worthwhile natural laboratory, and unraveled 45S rDNA diversity represents an interesting starting material to select subsets for rDNA transcription and alter the rRNA composition of ribosomes both intra- and inter-site.
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Affiliation(s)
- Valérie Delorme-Hinoux
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- EMR LGDP/MANGO, Mechanisms of Adaptation and Genomics, IRD-CNRS-UPVD, 66860 Perpignan, France
- Association Charles Flahault, 66350 Toulouges, France
| | - Assane Mbodj
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- EMR LGDP/MANGO, Mechanisms of Adaptation and Genomics, IRD-CNRS-UPVD, 66860 Perpignan, France
- Institut de Recherche pour le Développement (IRD), ECOBIO, 34000 Montpellier, France
| | - Sophie Brando
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
| | - Anne De Bures
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
| | - Christel Llauro
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- EMR LGDP/MANGO, Mechanisms of Adaptation and Genomics, IRD-CNRS-UPVD, 66860 Perpignan, France
| | - Fabrice Covato
- FRNC, Fédération des Réserves Naturelles Catalanes, 66500 Prades, France
| | - Joseph Garrigue
- FRNC, Fédération des Réserves Naturelles Catalanes, 66500 Prades, France
| | - Claude Guisset
- Association Charles Flahault, 66350 Toulouges, France
- FRNC, Fédération des Réserves Naturelles Catalanes, 66500 Prades, France
| | | | - Marie Mirouze
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- EMR LGDP/MANGO, Mechanisms of Adaptation and Genomics, IRD-CNRS-UPVD, 66860 Perpignan, France
- Institut de Recherche pour le Développement (IRD), ECOBIO, 34000 Montpellier, France
| | - Jean-Philippe Reichheld
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
| | - Julio Sáez-Vásquez
- Université de Perpignan Via Domitia (UPVD), Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
- Centre National de la Recherche Scientifique, Laboratoire Génome et Développement des Plantes (LGDP), UMR 5096, 66860 Perpignan, France
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6
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Borowska-Zuchowska N, Mykhailyk S, Robaszkiewicz E, Matysiak N, Mielanczyk L, Wojnicz R, Kovarik A, Hasterok R. Switch them off or not: selective rRNA gene repression in grasses. TRENDS IN PLANT SCIENCE 2023; 28:661-672. [PMID: 36764871 DOI: 10.1016/j.tplants.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/31/2022] [Accepted: 01/11/2023] [Indexed: 05/13/2023]
Abstract
Nucleolar dominance (ND) is selective epigenetic silencing of 35-48S rDNA loci. In allopolyploids, it is frequently manifested at the cytogenetic level by the inactivation of nucleolar organiser region(s) (NORs) inherited from one or several evolutionary ancestors. Grasses are ecologically and economically one of the most important land plant groups, which have frequently evolved through hybridisation and polyploidisation events. Here we review common and unique features of ND phenomena in this monocot family from cytogenetic, molecular, and genomic perspectives. We highlight recent advances achieved by using an allotetraploid model grass, Brachypodium hybridum, where ND commonly occurs at a population level, and we cover modern genomic approaches that decipher structural features of core arrays of NORs.
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Affiliation(s)
- Natalia Borowska-Zuchowska
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice 40-032, Poland.
| | - Serhii Mykhailyk
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice 40-032, Poland
| | - Ewa Robaszkiewicz
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice 40-032, Poland
| | - Natalia Matysiak
- Department of Histology and Cell Pathology, the Medical University of Silesia in Katowice, School of Medicine with the Division of Dentistry, Zabrze, Poland
| | - Lukasz Mielanczyk
- Department of Histology and Cell Pathology, the Medical University of Silesia in Katowice, School of Medicine with the Division of Dentistry, Zabrze, Poland; Silesian Nanomicroscopy Centre in Zabrze, Silesia LabMed - Research and Implementation Centre, Medical University of Silesia, Katowice, Poland
| | - Romuald Wojnicz
- Department of Histology and Cell Pathology, the Medical University of Silesia in Katowice, School of Medicine with the Division of Dentistry, Zabrze, Poland; Silesian Nanomicroscopy Centre in Zabrze, Silesia LabMed - Research and Implementation Centre, Medical University of Silesia, Katowice, Poland
| | - Ales Kovarik
- Department of Molecular Epigenetics, Institute of Biophysics, Czech Academy of Sciences, CZ-61200 Brno, Czech Republic
| | - Robert Hasterok
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental Protection, Faculty of Natural Sciences, University of Silesia in Katowice, Katowice 40-032, Poland.
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7
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Ding X, Chen J, Dai C, Shi P, Pan H, Lin Y, Chen Y, Gong L, Chen L, Wu W, Qiu X, Xu J, Huang Z, Liao B. Developing population identification tool based on polymorphism of rDNA for traditional Chinese medicine: Artemisia annua L. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 116:154882. [PMID: 37210961 DOI: 10.1016/j.phymed.2023.154882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/29/2023] [Accepted: 05/12/2023] [Indexed: 05/23/2023]
Abstract
BACKGROUND Artemisia annua, a well-known traditional Chinese medicine, is the main source for production of artemisinin, an anti-malaria drug. A. annua is distributed globally, with great diversity of morphological characteristics and artemisinin contents. Diverse traits among A. annua populations impeded the stable production of artemisinin, which needs an efficient tool to identify strains and assess population genetic homogeneity. PURPOSE In this study, ribosomal DNA (rDNA), were characterized for A. annua for strains identification and population genetic homogeneity assessment. METHODS The ribosomal RNA (rRNA) genes were identified using cmscan and assembled using rDNA unit of LQ-9 as a reference. rDNA among Asteraceae species were compared performing with 45S rDNA. The rDNA copy number was calculated based on sequencing depth. The polymorphisms of rDNA sequences were identified with bam-readcount, and confirmed by Sanger sequencing and restriction enzyme experiment. The ITS2 amplicon sequencing was used to verify the stability of ITS2 haplotype analysis. RESULTS Different from other Asteraceae species, 45S and 5S linked-type rDNA was only found in Artemisia genus. Rich polymorphisms of copy number and sequence of rDNA were identified in A. annua population. The haplotype composition of internal transcribed spacer 2 (ITS2) region which had moderate sequence polymorphism and relative short size was significantly different among A. annua strains. A population discrimination method was developed based on ITS2 haplotype analysis with high-throughput sequencing. CONCLUSION This study provides comprehensive characteristics of rDNA and suggests that ITS2 haplotype analysis is ideal tool for A. annua strain identification and population genetic homogeneity assessment.
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Affiliation(s)
- Xiaoxia Ding
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Jieting Chen
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Chunyan Dai
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Peiqi Shi
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Hengyu Pan
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Yanqi Lin
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Yikang Chen
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Lu Gong
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Linming Chen
- Guangzhou Huibiao Testing Technology Center, Guangzhou 510700, China
| | - Wenguang Wu
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Xiaohui Qiu
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China
| | - Jiang Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China.
| | - Zhihai Huang
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
| | - Baosheng Liao
- Key Laboratory of Quality Evaluation of Chinese Medicine of the Guangdong Provincial Medical Products Administration, the Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
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8
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Morton EA, Hall AN, Cuperus JT, Queitsch C. Substantial rDNA copy number reductions alter timing of development and produce variable tissue-specific phenotypes in C. elegans. Genetics 2023; 224:iyad039. [PMID: 36919976 PMCID: PMC10474940 DOI: 10.1093/genetics/iyad039] [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: 01/13/2023] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/16/2023] Open
Abstract
The genes that encode ribosomal RNAs are present in several hundred copies in most eukaryotes. These vast arrays of repetitive ribosomal DNA (rDNA) have been implicated not just in ribosome biogenesis, but also aging, cancer, genome stability, and global gene expression. rDNA copy number is highly variable among and within species; this variability is thought to associate with traits relevant to human health and disease. Here we investigate the phenotypic consequences of multicellular life at the lower bounds of rDNA copy number. We use the model Caenorhabditis elegans, which has previously been found to complete embryogenesis using only maternally provided ribosomes. We find that individuals with rDNA copy number reduced to ∼5% of wild type are capable of further development with variable penetrance. Such individuals are sterile and exhibit severe morphological defects, particularly in post-embryonically dividing tissues such as germline and vulva. Developmental completion and fertility are supported by an rDNA copy number ∼10% of wild type, with substantially delayed development. Worms with rDNA copy number reduced to ∼33% of wild type display a subtle developmental timing defect that was absent in worms with higher copy numbers. Our results support the hypothesis that rDNA requirements vary across tissues and indicate that the minimum rDNA copy number for fertile adulthood is substantially less than the lowest naturally observed total copy number. The phenotype of individuals with severely reduced rDNA copy number is highly variable in penetrance and presentation, highlighting the need for continued investigation into the biological consequences of rDNA copy number variation.
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Affiliation(s)
| | - Ashley N Hall
- Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Josh T Cuperus
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
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9
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Rabanal FA, Gräff M, Lanz C, Fritschi K, Llaca V, Lang M, Carbonell-Bejerano P, Henderson I, Weigel D. Pushing the limits of HiFi assemblies reveals centromere diversity between two Arabidopsis thaliana genomes. Nucleic Acids Res 2022; 50:12309-12327. [PMID: 36453992 PMCID: PMC9757041 DOI: 10.1093/nar/gkac1115] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 09/13/2022] [Accepted: 11/10/2022] [Indexed: 12/05/2022] Open
Abstract
Although long-read sequencing can often enable chromosome-level reconstruction of genomes, it is still unclear how one can routinely obtain gapless assemblies. In the model plant Arabidopsis thaliana, other than the reference accession Col-0, all other accessions de novo assembled with long-reads until now have used PacBio continuous long reads (CLR). Although these assemblies sometimes achieved chromosome-arm level contigs, they inevitably broke near the centromeres, excluding megabases of DNA from analysis in pan-genome projects. Since PacBio high-fidelity (HiFi) reads circumvent the high error rate of CLR technologies, albeit at the expense of read length, we compared a CLR assembly of accession Eyach15-2 to HiFi assemblies of the same sample. The use of five different assemblers starting from subsampled data allowed us to evaluate the impact of coverage and read length. We found that centromeres and rDNA clusters are responsible for 71% of contig breaks in the CLR scaffolds, while relatively short stretches of GA/TC repeats are at the core of >85% of the unfilled gaps in our best HiFi assemblies. Since the HiFi technology consistently enabled us to reconstruct gapless centromeres and 5S rDNA clusters, we demonstrate the value of the approach by comparing these previously inaccessible regions of the genome between the Eyach15-2 accession and the reference accession Col-0.
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Affiliation(s)
| | | | - Christa Lanz
- Department of Molecular Biology, Max Planck Institute for Biology Tübingen, 72076 Tübingen, Germany
| | - Katrin Fritschi
- Department of Molecular Biology, Max Planck Institute for Biology Tübingen, 72076 Tübingen, Germany
| | - Victor Llaca
- Genomics Technologies, Corteva Agriscience, Johnston, IA 50131, USA
| | - Michelle Lang
- Genomics Technologies, Corteva Agriscience, Johnston, IA 50131, USA
| | - Pablo Carbonell-Bejerano
- Department of Molecular Biology, Max Planck Institute for Biology Tübingen, 72076 Tübingen, Germany
| | - Ian Henderson
- Department of Plant Sciences, University of Cambridge, Cambridge, CB2 3EA, UK
| | - Detlef Weigel
- Correspondence may also be addressed to Detlef Weigel. Tel: +49 7071 601 1410;
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10
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Fefelova EA, Pleshakova IM, Mikhaleva EA, Pirogov SA, Poltorachenko V, Abramov Y, Romashin D, Shatskikh A, Blokh R, Gvozdev V, Klenov M. Impaired function of rDNA transcription initiation machinery leads to derepression of ribosomal genes with insertions of R2 retrotransposon. Nucleic Acids Res 2022; 50:867-884. [PMID: 35037046 PMCID: PMC8789037 DOI: 10.1093/nar/gkab1276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 11/21/2021] [Accepted: 12/14/2021] [Indexed: 12/14/2022] Open
Abstract
Eukaryotic genomes harbor hundreds of rRNA genes, many of which are transcriptionally silent. However, little is known about selective regulation of individual rDNA units. In Drosophila melanogaster, some rDNA repeats contain insertions of the R2 retrotransposon, which is capable to be transcribed only as part of pre-rRNA molecules. rDNA units with R2 insertions are usually inactivated, although R2 expression may be beneficial in cells with decreased rDNA copy number. Here we found that R2-inserted rDNA units are enriched with HP1a and H3K9me3 repressive mark, whereas disruption of the heterochromatin components slightly affects their silencing in ovarian germ cells. Surprisingly, we observed a dramatic upregulation of R2-inserted rRNA genes in ovaries lacking Udd (Under-developed) or other subunits (TAF1b and TAF1c-like) of the SL1-like complex, which is homologues to mammalian Selective factor 1 (SL1) involved in rDNA transcription initiation. Derepression of rRNA genes with R2 insertions was accompanied by a reduction of H3K9me3 and HP1a enrichment. We suggest that the impairment of the SL1-like complex affects a mechanism of selective activation of intact rDNA units which competes with heterochromatin formation. We also propose that R2 derepression may serve as an adaptive response to compromised rRNA synthesis.
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Affiliation(s)
- Elena A Fefelova
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena 91125, USA
| | - Irina M Pleshakova
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
- Laboratory for Neurobiology of Memory, P.K. Anokhin Institute of Normal Physiology, Moscow 125315, Russia
| | - Elena A Mikhaleva
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Sergei A Pirogov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Valentin A Poltorachenko
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Yuri A Abramov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Daniil D Romashin
- Laboratory of Precision Biosystems, V. N. Orekhovich Institute of Biomedical Chemistry, 10 Pogodinskaya St., Moscow 119121, Russia
| | - Aleksei S Shatskikh
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Roman S Blokh
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
- Department of Functional Genomics, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilova Street, Moscow 119334, Russia
| | - Vladimir A Gvozdev
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
| | - Mikhail S Klenov
- Department of Molecular Genetics of the Cell, Institute of Molecular Genetics of National Research Centre «Kurchatov Institute», Moscow 123182, Russia
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11
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Abstract
Although commonly regarded as nearly identical in sequence, 45S ribosomal RNA genes represent a massive source of genetic variation at different levels. Unfortunately, due to their repetitive nature and the difficulty to assemble their multiple copies in tandem, these important genomic elements remain largely unexplored in sequencing projects. Here, I describe how to exploit next generation sequencing data to estimate their copy number in an organism and detect true polymorphic sites within and among individuals. Furthermore, for species that carry multiple 45S ribosomal RNA gene clusters, I show how to make use of experimental populations to assign some of these variants to their cluster of origin.
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Affiliation(s)
- Fernando A Rabanal
- Department of Molecular Biology, Max Planck Institute for Biology, Tübingen, Germany.
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12
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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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13
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Vigneau J, Borg M. The epigenetic origin of life history transitions in plants and algae. PLANT REPRODUCTION 2021; 34:267-285. [PMID: 34236522 PMCID: PMC8566409 DOI: 10.1007/s00497-021-00422-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/14/2021] [Indexed: 05/17/2023]
Abstract
Plants and algae have a complex life history that transitions between distinct life forms called the sporophyte and the gametophyte. This phenomenon-called the alternation of generations-has fascinated botanists and phycologists for over 170 years. Despite the mesmerizing array of life histories described in plants and algae, we are only now beginning to learn about the molecular mechanisms controlling them and how they evolved. Epigenetic silencing plays an essential role in regulating gene expression during multicellular development in eukaryotes, raising questions about its impact on the life history strategy of plants and algae. Here, we trace the origin and function of epigenetic mechanisms across the plant kingdom, from unicellular green algae through to angiosperms, and attempt to reconstruct the evolutionary steps that influenced life history transitions during plant evolution. Central to this evolutionary scenario is the adaption of epigenetic silencing from a mechanism of genome defense to the repression and control of alternating generations. We extend our discussion beyond the green lineage and highlight the peculiar case of the brown algae. Unlike their unicellular diatom relatives, brown algae lack epigenetic silencing pathways common to animals and plants yet display complex life histories, hinting at the emergence of novel life history controls during stramenopile evolution.
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Affiliation(s)
- Jérômine Vigneau
- Department of Algal Development and Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Michael Borg
- Department of Algal Development and Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany.
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14
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Liu Q, Guo S, Zheng X, Shen X, Zhang T, Liao B, He W, Hu H, Cheng R, Xu J. Licorice Germplasm Resources Identification Using DNA Barcodes Inner-Variants. PLANTS (BASEL, SWITZERLAND) 2021; 10:plants10102036. [PMID: 34685843 PMCID: PMC8541099 DOI: 10.3390/plants10102036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 06/13/2023]
Abstract
Based on the gradual transformation from wild growth to artificial cultivation, the accurate authentication of licorice seeds contributes to the first committed step of its quality control and is pivotal to ensure the clinical efficacy of licorice. However, it is still challenging to obtain genetically stable licorice germplasm resources due to the multi-source, multi-heterozygous, polyploid, and hybrid characteristics of licorice seeds. Here, a new method for determining the heterozygosity of licorice seed mixture, based on the various sites, and finding the composition characteristics of licorice seed is preliminarily designed and proposed. Namely, high-throughput full-length multiple DNA barcodes(HFMD), based on ITS multi-copy variation exist, the full-length amplicons of ITS2, psbA-trnH and ITS are directly sequenced by rDNA through the next-generation sequence(NGS) and single-molecule real-time (SMRT) technologies. By comparing the three sequencing methods, our results proved that SMRT sequencing successfully identified the complete gradients of complex mixed samples with the best performance. Meanwhile, HFMD is a brilliant and feasible method for evaluating the heterozygosity of licorice seeds. It shows a perfect interpretation of DNA barcoding and can be applied in multi-base multi-heterozygous and polyploid species.
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Affiliation(s)
- Qianwen Liu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; (Q.L.); (T.Z.); (B.L.)
| | - Shuai Guo
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; (S.G.); (W.H.)
| | - Xiasheng Zheng
- Institute of Medicinal Plant Physiology and Ecology, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou 510006, China;
| | - Xiaofeng Shen
- Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences, Beijing 100193, China;
| | - Tianyi Zhang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; (Q.L.); (T.Z.); (B.L.)
| | - Baosheng Liao
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; (Q.L.); (T.Z.); (B.L.)
| | - Wenrui He
- School of Pharmacy, Chengdu University of Traditional Chinese Medicine, Chengdu 611137, China; (S.G.); (W.H.)
| | - Haoyu Hu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; (Q.L.); (T.Z.); (B.L.)
| | - Ruiyang Cheng
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; (Q.L.); (T.Z.); (B.L.)
| | - Jiang Xu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China; (Q.L.); (T.Z.); (B.L.)
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15
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Billiard S, Castric V, Llaurens V. The integrative biology of genetic dominance. Biol Rev Camb Philos Soc 2021; 96:2925-2942. [PMID: 34382317 PMCID: PMC9292577 DOI: 10.1111/brv.12786] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/29/2021] [Accepted: 07/30/2021] [Indexed: 11/29/2022]
Abstract
Dominance is a basic property of inheritance systems describing the link between a diploid genotype at a single locus and the resulting phenotype. Models for the evolution of dominance have long been framed as an opposition between the irreconcilable views of Fisher in 1928 supporting the role of largely elusive dominance modifiers and Wright in 1929, who viewed dominance as an emerging property of the structure of enzymatic pathways. Recent theoretical and empirical advances however suggest that these opposing views can be reconciled, notably using models investigating the regulation of gene expression and developmental processes. In this more comprehensive framework, phenotypic dominance emerges from departures from linearity between any levels of integration in the genotype‐to‐phenotype map. Here, we review how these different models illuminate the emergence and evolution of dominance. We then detail recent empirical studies shedding new light on the diversity of molecular and physiological mechanisms underlying dominance and its evolution. By reconciling population genetics and functional biology, we hope our review will facilitate cross‐talk among research fields in the integrative study of dominance evolution.
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Affiliation(s)
- Sylvain Billiard
- Univ. Lille, CNRS, UMR 8198 - Evo-Eco-Paleo, F-59000, Lille, France
| | - Vincent Castric
- Univ. Lille, CNRS, UMR 8198 - Evo-Eco-Paleo, F-59000, Lille, France
| | - Violaine Llaurens
- Institut de Systématique, Evolution et Biodiversité, CNRS/MNHN/Sorbonne Université/EPHE, Museum National d'Histoire Naturelle, CP50, 57 rue Cuvier, 75005, Paris, France
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16
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McKinlay A, Fultz D, Wang F, Pikaard CS. Targeted Enrichment of rRNA Gene Tandem Arrays for Ultra-Long Sequencing by Selective Restriction Endonuclease Digestion. FRONTIERS IN PLANT SCIENCE 2021; 12:656049. [PMID: 33995452 PMCID: PMC8113872 DOI: 10.3389/fpls.2021.656049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 04/06/2021] [Indexed: 05/26/2023]
Abstract
Large regions of nearly identical repeats, such as the 45S ribosomal RNA (rRNA) genes of Nucleolus Organizer Regions (NORs), can account for major gaps in sequenced genomes. To assemble these regions, ultra-long sequencing reads that span multiple repeats have the potential to reveal sets of repeats that collectively have sufficient sequence variation to unambiguously define that interval and recognize overlapping reads. Because individual repetitive loci typically represent a small proportion of the genome, methods to enrich for the regions of interest are desirable. Here we describe a simple method that achieves greater than tenfold enrichment of Arabidopsis thaliana 45S rRNA gene sequences among ultra-long Oxford Nanopore Technology sequencing reads. This method employs agarose-embedded genomic DNA that is subjected to restriction endonucleases digestion using a cocktail of enzymes predicted to be non-cutters of rRNA genes. Most of the genome is digested into small fragments that diffuse out of the agar plugs, whereas rRNA gene arrays are retained. In principle, the approach can also be adapted for sequencing other repetitive loci for which gaps exist in a reference genome.
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Affiliation(s)
- Anastasia McKinlay
- Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States
| | - Dalen Fultz
- Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, United States
| | - Feng Wang
- Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, United States
| | - Craig S. Pikaard
- Department of Biology and Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN, United States
- Howard Hughes Medical Institute, Indiana University, Bloomington, IN, United States
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17
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Sequencing of the Arabidopsis NOR2 reveals its distinct organization and tissue-specific rRNA ribosomal variants. Nat Commun 2021; 12:387. [PMID: 33452254 PMCID: PMC7810690 DOI: 10.1038/s41467-020-20728-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/15/2020] [Indexed: 11/20/2022] Open
Abstract
Despite vast differences between organisms, some characteristics of their genomes are conserved, such as the nucleolus organizing region (NOR). The NOR is constituted of multiple, highly repetitive rDNA genes, encoding the catalytic ribosomal core RNAs which are transcribed from 45S rDNA units. Their precise sequence information and organization remain uncharacterized. Here, using a combination of long- and short-read sequencing technologies we assemble contigs of the Arabidopsis NOR2 rDNA domain. We identify several expressed rRNA gene variants which are integrated into translating ribosomes in a tissue-specific manner. These findings support the concept of tissue specific ribosome subpopulations that differ in their rRNA composition and provide insights into the higher order organization of NOR2. The nucleolus organizing region (NOR) consists of multiple, highly repetitive rDNA genes. Here Sims et al. use both long- and short-read sequencing to determine the organization and sequence of Arabidopsis NOR2 rDNA and show that different rRNA gene variants are integrated into translating ribosomes in a tissue-specific manner.
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18
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Sims J, Rabanal FA, Elgert C, von Haeseler A, Schlögelhofer P. It Is Just a Matter of Time: Balancing Homologous Recombination and Non-homologous End Joining at the rDNA Locus During Meiosis. FRONTIERS IN PLANT SCIENCE 2021; 12:773052. [PMID: 34777453 PMCID: PMC8580885 DOI: 10.3389/fpls.2021.773052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 10/04/2021] [Indexed: 05/17/2023]
Abstract
Ribosomal RNA genes (rDNAs) are located in large domains of hundreds of rDNA units organized in a head-to-tail manner. The proper and stable inheritance of rDNA clusters is of paramount importance for survival. Yet, these highly repetitive elements pose a potential risk to the genome since they can undergo non-allelic exchanges. Here, we review the current knowledge of the organization of the rDNA clusters in Arabidopsis thaliana and their stability during meiosis. Recent findings suggest that during meiosis, all rDNA loci are embedded within the nucleolus favoring non-homologous end joining (NHEJ) as a repair mechanism, while DNA repair via homologous recombination (HR) appears to be a rare event. We propose a model where (1) frequent meiotic NHEJ events generate abundant single nucleotide polymorphisms and insertions/deletions within the rDNA, resulting in a heterogeneous population of rDNA units and (2) rare HR events dynamically change rDNA unit numbers, only to be observed in large populations over many generations. Based on the latest efforts to delineate the entire rDNA sequence in A. thaliana, we discuss evidence supporting this model. The results compiled so far draw a surprising picture of rDNA sequence heterogeneity between individual units. Furthermore, rDNA cluster sizes have been recognized as relatively stable when observing less than 10 generations, yet emerged as major determinant of genome size variation between different A. thaliana ecotypes. The sequencing efforts also revealed that transcripts from the diverse rDNA units yield heterogenous ribosome populations with potential functional implications. These findings strongly motivate further research to understand the mechanisms that maintain the metastable state of rDNA loci.
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Affiliation(s)
- Jason Sims
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- *Correspondence: Jason Sims,
| | - Fernando A. Rabanal
- Department of Molecular Biology, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Christiane Elgert
- Center for Integrative Bioinformatics Vienna (CIBIV), Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna BioCenter, Vienna, Austria
| | - Arndt von Haeseler
- Center for Integrative Bioinformatics Vienna (CIBIV), Max Perutz Labs, University of Vienna and Medical University of Vienna, Vienna BioCenter, Vienna, Austria
- Bioinformatics and Computational Biology, Faculty of Computer Science, University of Vienna, Vienna, Austria
| | - Peter Schlögelhofer
- Department of Chromosome Biology, Max Perutz Labs, University of Vienna, Vienna BioCenter, Vienna, Austria
- Peter Schlögelhofer,
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19
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Burns R, Mandáková T, Gunis J, Soto-Jiménez LM, Liu C, Lysak MA, Novikova PY, Nordborg M. Gradual evolution of allopolyploidy in Arabidopsis suecica. Nat Ecol Evol 2021; 5:1367-1381. [PMID: 34413506 PMCID: PMC8484011 DOI: 10.1038/s41559-021-01525-w] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 07/01/2021] [Indexed: 02/06/2023]
Abstract
Most diploid organisms have polyploid ancestors. The evolutionary process of polyploidization is poorly understood but has frequently been conjectured to involve some form of 'genome shock', such as genome reorganization and subgenome expression dominance. Here we study polyploidization in Arabidopsis suecica, a post-glacial allopolyploid species formed via hybridization of Arabidopsis thaliana and Arabidopsis arenosa. We generated a chromosome-level genome assembly of A. suecica and complemented it with polymorphism and transcriptome data from all species. Despite a divergence around 6 million years ago (Ma) between the ancestral species and differences in their genome composition, we see no evidence of a genome shock: the A. suecica genome is colinear with the ancestral genomes; there is no subgenome dominance in expression; and transposon dynamics appear stable. However, we find changes suggesting gradual adaptation to polyploidy. In particular, the A. thaliana subgenome shows upregulation of meiosis-related genes, possibly to prevent aneuploidy and undesirable homeologous exchanges that are observed in synthetic A. suecica, and the A. arenosa subgenome shows upregulation of cyto-nuclear processes, possibly in response to the new cytoplasmic environment of A. suecica, with plastids maternally inherited from A. thaliana. These changes are not seen in synthetic hybrids, and thus are likely to represent subsequent evolution.
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Affiliation(s)
- Robin Burns
- grid.24194.3a0000 0000 9669 8503Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Terezie Mandáková
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, and Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Joanna Gunis
- grid.24194.3a0000 0000 9669 8503Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Luz Mayela Soto-Jiménez
- grid.24194.3a0000 0000 9669 8503Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Chang Liu
- grid.9464.f0000 0001 2290 1502Institute of Biology, University of Hohenheim, Stuttgart, Germany
| | - Martin A. Lysak
- grid.10267.320000 0001 2194 0956CEITEC - Central European Institute of Technology, and Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Polina Yu. Novikova
- grid.511033.5VIB-UGent Center for Plant Systems Biology, Ghent, Belgium ,grid.419498.90000 0001 0660 6765Department of Chromosome Biology, Max Planck Institute for Plant Breeding Research, Cologne, Germany
| | - Magnus Nordborg
- grid.24194.3a0000 0000 9669 8503Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
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20
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Borowska‐Zuchowska N, Kovarik A, Robaszkiewicz E, Tuna M, Tuna GS, Gordon S, Vogel JP, Hasterok R. The fate of 35S rRNA genes in the allotetraploid grass Brachypodium hybridum. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2020; 103:1810-1825. [PMID: 32506573 PMCID: PMC7497271 DOI: 10.1111/tpj.14869] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/20/2020] [Accepted: 05/28/2020] [Indexed: 05/22/2023]
Abstract
Nucleolar dominance (ND) consists of the reversible silencing of 35S/45S rDNA loci inherited from one of the ancestors of an allopolyploid. The molecular mechanisms by which one ancestral rDNA set is selected for silencing remain unclear. We applied a combination of molecular (Southern blot hybridization and reverse-transcription cleaved amplified polymorphic sequence analysis), genomic (analysis of variants) and cytogenetic (fluorescence in situ hybridization) approaches to study the structure, expression and epigenetic landscape of 35S rDNA in an allotetraploid grass that exhibits ND, Brachypodium hybridum (genome composition DDSS), and its putative progenitors, Brachypodium distachyon (DD) and Brachypodium stacei (SS). In progenitor genomes, B. stacei showed a higher intragenomic heterogeneity of rDNA compared with B. distachyon. In all studied accessions of B. hybridum, there was a reduction in the copy number of S homoeologues, which was accompanied by their inactive transcriptional status. The involvement of DNA methylation in CG and CHG contexts in the silencing of the S-genome rDNA loci was revealed. In the B. hybridum allotetraploid, ND is stabilized towards the D-genome units, irrespective of the polyphyletic origin of the species, and does not seem to be influenced by homoeologous 35S rDNA ratios and developmental stage.
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Affiliation(s)
- Natalia Borowska‐Zuchowska
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental ProtectionFaculty of Natural SciencesUniversity of Silesia in KatowiceJagiellonska 28Katowice40‐032Poland
| | - Ales Kovarik
- Department of Molecular EpigeneticsInstitute of BiophysicsAcademy of Sciences of the Czech Republic, v.v.i.Královopolská 135Brno612 65Czech Republic
| | - Ewa Robaszkiewicz
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental ProtectionFaculty of Natural SciencesUniversity of Silesia in KatowiceJagiellonska 28Katowice40‐032Poland
| | - Metin Tuna
- Department of Field CropsFaculty of AgricultureTekirdag Namik Kemal UniversitySuleymanpasaTekirdag59030Turkey
| | | | - Sean Gordon
- US Department of Energy (DOE) Joint Genome Institute (JGI)BerkeleyCA94720USA
| | - John P. Vogel
- US Department of Energy (DOE) Joint Genome Institute (JGI)BerkeleyCA94720USA
- University CaliforniaBerkeley, BerkeleyCA94720USA
| | - Robert Hasterok
- Plant Cytogenetics and Molecular Biology Group, Institute of Biology, Biotechnology and Environmental ProtectionFaculty of Natural SciencesUniversity of Silesia in KatowiceJagiellonska 28Katowice40‐032Poland
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21
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ASY1 acts as a dosage-dependent antagonist of telomere-led recombination and mediates crossover interference in Arabidopsis. Proc Natl Acad Sci U S A 2020; 117:13647-13658. [PMID: 32499315 PMCID: PMC7306779 DOI: 10.1073/pnas.1921055117] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During meiosis, interhomolog recombination produces crossovers and noncrossovers to create genetic diversity. Meiotic recombination frequency varies at multiple scales, with high subtelomeric recombination and suppressed centromeric recombination typical in many eukaryotes. During recombination, sister chromatids are tethered as loops to a polymerized chromosome axis, which, in plants, includes the ASY1 HORMA domain protein and REC8-cohesin complexes. Using chromatin immunoprecipitation, we show an ascending telomere-to-centromere gradient of ASY1 enrichment, which correlates strongly with REC8-cohesin ChIP-seq data. We mapped crossovers genome-wide in the absence of ASY1 and observe that telomere-led recombination becomes dominant. Surprisingly, asy1/+ heterozygotes also remodel crossovers toward subtelomeric regions at the expense of the pericentromeres. Telomeric recombination increases in asy1/+ occur in distal regions where ASY1 and REC8 ChIP enrichment are lowest in wild type. In wild type, the majority of crossovers show interference, meaning that they are more widely spaced along the chromosomes than expected by chance. To measure interference, we analyzed double crossover distances, MLH1 foci, and fluorescent pollen tetrads. Interestingly, while crossover interference is normal in asy1/+, it is undetectable in asy1 mutants, indicating that ASY1 is required to mediate crossover interference. Together, this is consistent with ASY1 antagonizing telomere-led recombination and promoting spaced crossover formation along the chromosomes via interference. These findings provide insight into the role of the meiotic axis in patterning recombination frequency within plant genomes.
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22
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Regulation of Nucleolar Dominance in Drosophila melanogaster. Genetics 2020; 214:991-1004. [PMID: 32122935 PMCID: PMC7153946 DOI: 10.1534/genetics.119.302471] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 02/26/2020] [Indexed: 12/18/2022] Open
Abstract
In eukaryotic genomes, ribosomal RNA (rRNA) genes exist as tandemly repeated clusters, forming ribosomal DNA (rDNA) loci. Each rDNA locus typically contains hundreds of rRNA genes to meet the high demand of ribosome biogenesis. Nucleolar dominance is a phenomenon whereby individual rDNA loci are entirely silenced or transcribed, and is believed to be a mechanism to control rRNA dosage. Nucleolar dominance was originally noted to occur in interspecies hybrids, and has been shown to occur within a species (i.e., nonhybrid context). However, studying nucleolar dominance within a species has been challenging due to the highly homogenous sequence across rDNA loci. By utilizing single nucleotide polymorphisms between X rDNA and Y rDNA loci in males, as well as sequence variations between two X rDNA loci in females, we conducted a thorough characterization of nucleolar dominance throughout development of Drosophila melanogaster. We demonstrate that nucleolar dominance is a developmentally regulated program that occurs in nonhybrid, wild-type D. melanogaster, where Y rDNA dominance is established during male embryogenesis, whereas females normally do not exhibit dominance between two X rDNA loci. By utilizing various chromosomal complements (e.g., X/Y, X/X, X/X/Y) and a chromosome rearrangement, we show that the short arm of the Y chromosome including the Y rDNA likely contains information that instructs the state of nucleolar dominance. Our study begins to reveal the mechanisms underlying the selection of rDNA loci for activation/silencing in nucleolar dominance in the context of nonhybrid D. melanogaster.
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23
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Montgomery SA, Tanizawa Y, Galik B, Wang N, Ito T, Mochizuki T, Akimcheva S, Bowman JL, Cognat V, Maréchal-Drouard L, Ekker H, Hong SF, Kohchi T, Lin SS, Liu LYD, Nakamura Y, Valeeva LR, Shakirov EV, Shippen DE, Wei WL, Yagura M, Yamaoka S, Yamato KT, Liu C, Berger F. Chromatin Organization in Early Land Plants Reveals an Ancestral Association between H3K27me3, Transposons, and Constitutive Heterochromatin. Curr Biol 2020; 30:573-588.e7. [PMID: 32004456 PMCID: PMC7209395 DOI: 10.1016/j.cub.2019.12.015] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 12/03/2019] [Accepted: 12/05/2019] [Indexed: 12/16/2022]
Abstract
Genome packaging by nucleosomes is a hallmark of eukaryotes. Histones and the pathways that deposit, remove, and read histone modifications are deeply conserved. Yet, we lack information regarding chromatin landscapes in extant representatives of ancestors of the main groups of eukaryotes, and our knowledge of the evolution of chromatin-related processes is limited. We used the bryophyte Marchantia polymorpha, which diverged from vascular plants circa 400 mya, to obtain a whole chromosome genome assembly and explore the chromatin landscape and three-dimensional genome organization in an early diverging land plant lineage. Based on genomic profiles of ten chromatin marks, we conclude that the relationship between active marks and gene expression is conserved across land plants. In contrast, we observed distinctive features of transposons and other repetitive sequences in Marchantia compared with flowering plants. Silenced transposons and repeats did not accumulate around centromeres. Although a large fraction of constitutive heterochromatin was marked by H3K9 methylation as in flowering plants, a significant proportion of transposons were marked by H3K27me3, which is otherwise dedicated to the transcriptional repression of protein-coding genes in flowering plants. Chromatin compartmentalization analyses of Hi-C data revealed that repressed B compartments were densely decorated with H3K27me3 but not H3K9 or DNA methylation as reported in flowering plants. We conclude that, in early plants, H3K27me3 played an essential role in heterochromatin function, suggesting an ancestral role of this mark in transposon silencing.
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Affiliation(s)
- Sean A Montgomery
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr Gasse 3, 1030 Vienna, Austria
| | - Yasuhiro Tanizawa
- Department of Informatics, National Institute of Genetics, Research Organization of Information and Systems, 1111 Yata, Mishima, Japan
| | - Bence Galik
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr Gasse 3, 1030 Vienna, Austria
| | - Nan Wang
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany
| | - Tasuku Ito
- John Innes Centre, Colney lane, Norwich NR4 7UH, UK
| | - Takako Mochizuki
- Department of Informatics, National Institute of Genetics, Research Organization of Information and Systems, 1111 Yata, Mishima, Japan
| | - Svetlana Akimcheva
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr Gasse 3, 1030 Vienna, Austria
| | - John L Bowman
- School of Biological Sciences, Monash University, Melbourne, 3800 VIC, Australia
| | - Valérie Cognat
- Institut de biologie moléculaire des plantes-CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Laurence Maréchal-Drouard
- Institut de biologie moléculaire des plantes-CNRS, Université de Strasbourg, 12 rue du Général Zimmer, 67084 Strasbourg, France
| | - Heinz Ekker
- Vienna BioCenter Core Facilities (VBCF), Next Generation Sequencing facility, Dr. Bohr Gasse 3, 1030 Vienna, Austria
| | - Syuan-Fei Hong
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Shih-Shun Lin
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Li-Yu Daisy Liu
- Department of Agronomy, National Taiwan University, Taipei 106, Taiwan
| | - Yasukazu Nakamura
- Department of Informatics, National Institute of Genetics, Research Organization of Information and Systems, 1111 Yata, Mishima, Japan
| | - Lia R Valeeva
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Republic of Tatarstan 420008, Russia
| | - Eugene V Shakirov
- Institute of Fundamental Medicine and Biology, Kazan (Volga Region) Federal University, Kazan, Republic of Tatarstan 420008, Russia; Department of Biological Sciences, Marshall University, Huntington, WV 25701, USA
| | - Dorothy E Shippen
- Department of Biochemistry and Biophysics, Texas A&M University, 2128 TAMU, College Station, TX 77843-2128, USA
| | - Wei-Lun Wei
- Institute of Biotechnology, National Taiwan University, Taipei 106, Taiwan
| | - Masaru Yagura
- Department of Informatics, National Institute of Genetics, Research Organization of Information and Systems, 1111 Yata, Mishima, Japan
| | - Shohei Yamaoka
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Katsuyuki T Yamato
- Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama 649-6493, Japan
| | - Chang Liu
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Auf der Morgenstelle 32, 72076 Tübingen, Germany.
| | - Frédéric Berger
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr Gasse 3, 1030 Vienna, Austria.
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24
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Abstract
Individuals within a species can exhibit vast variation in copy number of repetitive DNA elements. This variation may contribute to complex traits such as lifespan and disease, yet it is only infrequently considered in genotype-phenotype associations. Although the possible importance of copy number variation is widely recognized, accurate copy number quantification remains challenging. Here, we assess the technical reproducibility of several major methods for copy number estimation as they apply to the large repetitive ribosomal DNA array (rDNA). rDNA encodes the ribosomal RNAs and exists as a tandem gene array in all eukaryotes. Repeat units of rDNA are kilobases in size, often with several hundred units comprising the array, making rDNA particularly intractable to common quantification techniques. We evaluate pulsed-field gel electrophoresis, droplet digital PCR, and Nextera-based whole genome sequencing as approaches to copy number estimation, comparing techniques across model organisms and spanning wide ranges of copy numbers. Nextera-based whole genome sequencing, though commonly used in recent literature, produced high error. We explore possible causes for this error and provide recommendations for best practices in rDNA copy number estimation. We present a resource of high-confidence rDNA copy number estimates for a set of S. cerevisiae and C. elegans strains for future use. We furthermore explore the possibility for FISH-based copy number estimation, an alternative that could potentially characterize copy number on a cellular level.
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25
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Zhang H, Zheng R, Wang Y, Zhang Y, Hong P, Fang Y, Li G, Fang Y. The effects of Arabidopsis genome duplication on the chromatin organization and transcriptional regulation. Nucleic Acids Res 2019; 47:7857-7869. [PMID: 31184697 PMCID: PMC6736098 DOI: 10.1093/nar/gkz511] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 05/26/2019] [Accepted: 05/30/2019] [Indexed: 12/20/2022] Open
Abstract
Autopolyploidy is widespread in higher plants and important for agricultural yield and quality. However, the effects of genome duplication on the chromatin organization and transcriptional regulation are largely unknown in plants. Using High-throughput Chromosome Conformation Capture (Hi-C), we showed that autotetraploid Arabidopsis presented more inter-chromosomal interactions and fewer short-range chromatin interactions compared with its diploid progenitor. In addition, genome duplication contributed to the switching of some loose and compact structure domains with altered H3K4me3 and H3K27me3 histone modification status. 539 genes were identified with altered transcriptions and chromatin interactions in autotetraploid Arabidopsis. Especially, we found that genome duplication changed chromatin looping and H3K27me3 histone modification in Flowering Locus C. We propose that genome doubling modulates the transcription genome-wide by changed chromatin interactions and at the specific locus by altered chromatin loops and histone modifications.
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Affiliation(s)
- Hui Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Ruiqin Zheng
- National Key Laboratory of Crop Genetic Improvement, Hubei Key Laboratory of Agricultural Bioinformatics, Hubei Engineering Technology Research Center of Agricultural Big Data, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Yunlong Wang
- National Key Laboratory of Crop Genetic Improvement, Hubei Key Laboratory of Agricultural Bioinformatics, Hubei Engineering Technology Research Center of Agricultural Big Data, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Yu Zhang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Ping Hong
- National Key Laboratory of Crop Genetic Improvement, Hubei Key Laboratory of Agricultural Bioinformatics, Hubei Engineering Technology Research Center of Agricultural Big Data, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Yaping Fang
- National Key Laboratory of Crop Genetic Improvement, Hubei Key Laboratory of Agricultural Bioinformatics, Hubei Engineering Technology Research Center of Agricultural Big Data, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Guoliang Li
- National Key Laboratory of Crop Genetic Improvement, Hubei Key Laboratory of Agricultural Bioinformatics, Hubei Engineering Technology Research Center of Agricultural Big Data, College of Informatics, Huazhong Agricultural University, Wuhan 430070, China
| | - Yuda Fang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Sciences; University of Chinese Academy of Sciences, Shanghai 200032, China
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Simon L, Rabanal FA, Dubos T, Oliver C, Lauber D, Poulet A, Vogt A, Mandlbauer A, Le Goff S, Sommer A, Duborjal H, Tatout C, Probst AV. Genetic and epigenetic variation in 5S ribosomal RNA genes reveals genome dynamics in Arabidopsis thaliana. Nucleic Acids Res 2019. [PMID: 29518237 PMCID: PMC5887818 DOI: 10.1093/nar/gky163] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Organized in tandem repeat arrays in most eukaryotes and transcribed by RNA polymerase III, expression of 5S rRNA genes is under epigenetic control. To unveil mechanisms of transcriptional regulation, we obtained here in depth sequence information on 5S rRNA genes from the Arabidopsis thaliana genome and identified differential enrichment in epigenetic marks between the three 5S rDNA loci situated on chromosomes 3, 4 and 5. We reveal the chromosome 5 locus as the major source of an atypical, long 5S rRNA transcript characteristic of an open chromatin structure. 5S rRNA genes from this locus translocated in the Landsberg erecta ecotype as shown by linkage mapping and chromosome-specific FISH analysis. These variations in 5S rDNA locus organization cause changes in the spatial arrangement of chromosomes in the nucleus. Furthermore, 5S rRNA gene arrangements are highly dynamic with alterations in chromosomal positions through translocations in certain mutants of the RNA-directed DNA methylation pathway and important copy number variations among ecotypes. Finally, variations in 5S rRNA gene sequence, chromatin organization and transcripts indicate differential usage of 5S rDNA loci in distinct ecotypes. We suggest that both the usage of existing and new 5S rDNA loci resulting from translocations may impact neighboring chromatin organization.
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Affiliation(s)
- Lauriane Simon
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
| | - Fernando A Rabanal
- Gregor Mendel Institute (GMI), Austrian Academy of Sciences, Vienna BioCenter (VBC), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Tristan Dubos
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
| | - Cecilia Oliver
- Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid 28040, Spain
| | - Damien Lauber
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
| | - Axel Poulet
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
| | - Alexander Vogt
- Vienna Biocenter Core Facilities GmbH (VBCF), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Ariane Mandlbauer
- Vienna Biocenter Core Facilities GmbH (VBCF), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Samuel Le Goff
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
| | - Andreas Sommer
- Vienna Biocenter Core Facilities GmbH (VBCF), Dr. Bohr-Gasse 3, 1030 Vienna, Austria
| | - Hervé Duborjal
- Plant Engineering Platform, BIOGEMMA, Route d'Ennezat Centre de Recherche de Chappes, 63720 Chappes, France
| | - Christophe Tatout
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
| | - Aline V Probst
- GReD, Université Clermont Auvergne, CNRS, INSERM, BP 38, 63001 Clermont-Ferrand, France
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27
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Herklotz V, Kovařík A, Lunerová J, Lippitsch S, Groth M, Ritz CM. The fate of ribosomal RNA genes in spontaneous polyploid dogrose hybrids [Rosa L. sect. Caninae (DC.) Ser.] exhibiting non-symmetrical meiosis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 94:77-90. [PMID: 29385286 DOI: 10.1111/tpj.13843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 01/03/2018] [Accepted: 01/15/2018] [Indexed: 05/02/2023]
Abstract
Dogroses represent an exceptional system for studying the effects of genome doubling and hybridization: their asymmetrical meiosis enables recombination in bi-parentally inherited chromosomes but prevents it in maternally inherited ones. We employed fluorescent in situ hybridization, genome skimming, amplicon sequencing of genomic and cDNA as well as conventional cloning of nuclear ribosomal DNA in two phylogenetically distinct pentaploid (2n = 5x = 35) species, Rosa canina and Rosa inodora, and their naturally occurring reciprocal hybrids, Rosa dumalis (5x) and Rosa agrestis (5x, 6x). Both progenitor species differed in composition, meiotic behaviour and expression of rDNA loci: R. canina (five 18S and 5-8 5S loci) was dominated by the Canina ribotypes, but R. inodora (four 18S loci and 7-8 5S loci) by the Rubiginosa ribotype. The co-localized 5S/18S loci occurred on either bivalent-forming (R. canina) or univalent-forming (R. inodora) chromosomes. Ribosomal DNA loci were additively inherited; however, the Canina ribotypes were dominantly expressed, even in genotypes with relatively low copy number of these genes. Moreover, we observed rDNA homogenization towards the paternally transmitted Canina ribotype in 6x R. agrestis. The here-observed variation in arrangement and composition of rDNA types between R. canina and R. inodora suggests the involvement of different genomes in bivalent formation. This results supports the hypothesis that the asymmetrical meiosis arose at least twice by independent ancient hybridization events.
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Affiliation(s)
- Veit Herklotz
- Department of Botany, Senckenberg Museum of Natural History Görlitz, Am Museum 1, D-02826, Görlitz, Germany
| | - Aleš Kovařík
- Department of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, 612 65, Brno, Czech Republic
| | - Jana Lunerová
- Department of Molecular Epigenetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Královopolská 135, 612 65, Brno, Czech Republic
| | - Susan Lippitsch
- Department of Ecology and Environment Protection, University of Applied Sciences Zittau/Görlitz, Theodor-Körner-Allee 16, D-02763, Zittau, Germany
| | - Marco Groth
- Leibniz Institute on Aging - Fritz Lipmann Institute, Beutenbergstr. 11, D-07745, Jena, Germany
| | - Christiane M Ritz
- Department of Botany, Senckenberg Museum of Natural History Görlitz, Am Museum 1, D-02826, Görlitz, Germany
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