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Kreiner JM, Hnatovska S, Stinchcombe JR, Wright SI. Quantifying the role of genome size and repeat content in adaptive variation and the architecture of flowering time in Amaranthus tuberculatus. PLoS Genet 2023; 19:e1010865. [PMID: 38150485 PMCID: PMC10775983 DOI: 10.1371/journal.pgen.1010865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 01/09/2024] [Accepted: 12/11/2023] [Indexed: 12/29/2023] Open
Abstract
Genome size variation, largely driven by repeat content, is poorly understood within and among populations, limiting our understanding of its significance for adaptation. Here we characterize intraspecific variation in genome size and repeat content across 186 individuals of Amaranthus tuberculatus, a ubiquitous native weed that shows flowering time adaptation to climate across its range and in response to agriculture. Sequence-based genome size estimates vary by up to 20% across individuals, consistent with the considerable variability in the abundance of transposable elements, unknown repeats, and rDNAs across individuals. The additive effect of this variation has important phenotypic consequences-individuals with more repeats, and thus larger genomes, show slower flowering times and growth rates. However, compared to newly-characterized gene copy number and polygenic nucleotide changes underlying variation in flowering time, we show that genome size is a marginal contributor. Differences in flowering time are reflected by genome size variation across sexes and marginally, habitats, while polygenic variation and a gene copy number variant within the ATP synthesis pathway show consistently stronger environmental clines than genome size. Repeat content nonetheless shows non-neutral distributions across the genome, and across latitudinal and environmental gradients, demonstrating the numerous governing processes that in turn influence quantitative genetic variation for phenotypes key to plant adaptation.
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Affiliation(s)
- Julia M. Kreiner
- Department of Botany, Biodiversity Research Centre, University of British Columbia
- Department of Ecology & Evolutionary Biology, University of Toronto
| | - Solomiya Hnatovska
- Department of Ecology & Evolutionary Biology, University of Toronto
- Department of Molecular Genetics, University of Toronto
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2
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Orozco-Arias S, Humberto Lopez-Murillo L, Candamil-Cortés MS, Arias M, Jaimes PA, Rossi Paschoal A, Tabares-Soto R, Isaza G, Guyot R. Inpactor2: a software based on deep learning to identify and classify LTR-retrotransposons in plant genomes. Brief Bioinform 2022; 24:6887110. [PMID: 36502372 PMCID: PMC9851300 DOI: 10.1093/bib/bbac511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/13/2022] [Accepted: 10/26/2022] [Indexed: 12/14/2022] Open
Abstract
LTR-retrotransposons are the most abundant repeat sequences in plant genomes and play an important role in evolution and biodiversity. Their characterization is of great importance to understand their dynamics. However, the identification and classification of these elements remains a challenge today. Moreover, current software can be relatively slow (from hours to days), sometimes involve a lot of manual work and do not reach satisfactory levels in terms of precision and sensitivity. Here we present Inpactor2, an accurate and fast application that creates LTR-retrotransposon reference libraries in a very short time. Inpactor2 takes an assembled genome as input and follows a hybrid approach (deep learning and structure-based) to detect elements, filter partial sequences and finally classify intact sequences into superfamilies and, as very few tools do, into lineages. This tool takes advantage of multi-core and GPU architectures to decrease execution times. Using the rice genome, Inpactor2 showed a run time of 5 minutes (faster than other tools) and has the best accuracy and F1-Score of the tools tested here, also having the second best accuracy and specificity only surpassed by EDTA, but achieving 28% higher sensitivity. For large genomes, Inpactor2 is up to seven times faster than other available bioinformatics tools.
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Affiliation(s)
- Simon Orozco-Arias
- Corresponding authors. Simon Orozco-Arias, Computer Science Department, Universidad Autónoma de Manizales, Antigua Estación del Ferrocarrill, Manizalez, Colombia. Tel.: +57(606)8727272 - 8727709 Ext 102; E-mail: ; Alexandre Rossi Paschoal, Department of Computer Science, Bioinformatics and Pattern Recognition Group, Graduation Program in Bioinformatics, Federal University of Technology - Paraná, UTFPR, Cornélio Procópio, Paraná, 86300-000, Brazil. Tel.: +433133-3790; E-mail: ; Gustavo Isaza, Systems and Informatics Department, Center for Technology Development - Bioprocess and Agro-industry Plant, Universidad de Caldas, St 65 #26-10, Manizales, Colombia. Tel.: +57(606)8781500 ext 13146; E-mail: , Romain Guyot, IRD, 911 Av. Agropolis, 34394 Montpellier, France. Tel.: +334674160000; E-mail:
| | | | | | - Maradey Arias
- Department of Computer Science, Universidad Autónoma de Manizales, 170001, Caldas, Colombia
| | - Paula A Jaimes
- Department of Computer Science, Universidad Autónoma de Manizales, 170001, Caldas, Colombia
| | - Alexandre Rossi Paschoal
- Corresponding authors. Simon Orozco-Arias, Computer Science Department, Universidad Autónoma de Manizales, Antigua Estación del Ferrocarrill, Manizalez, Colombia. Tel.: +57(606)8727272 - 8727709 Ext 102; E-mail: ; Alexandre Rossi Paschoal, Department of Computer Science, Bioinformatics and Pattern Recognition Group, Graduation Program in Bioinformatics, Federal University of Technology - Paraná, UTFPR, Cornélio Procópio, Paraná, 86300-000, Brazil. Tel.: +433133-3790; E-mail: ; Gustavo Isaza, Systems and Informatics Department, Center for Technology Development - Bioprocess and Agro-industry Plant, Universidad de Caldas, St 65 #26-10, Manizales, Colombia. Tel.: +57(606)8781500 ext 13146; E-mail: , Romain Guyot, IRD, 911 Av. Agropolis, 34394 Montpellier, France. Tel.: +334674160000; E-mail:
| | - Reinel Tabares-Soto
- Department of Electronics and Automation, Universidad Autónoma de Manizales, 170001, Caldas, Colombia
| | - Gustavo Isaza
- Corresponding authors. Simon Orozco-Arias, Computer Science Department, Universidad Autónoma de Manizales, Antigua Estación del Ferrocarrill, Manizalez, Colombia. Tel.: +57(606)8727272 - 8727709 Ext 102; E-mail: ; Alexandre Rossi Paschoal, Department of Computer Science, Bioinformatics and Pattern Recognition Group, Graduation Program in Bioinformatics, Federal University of Technology - Paraná, UTFPR, Cornélio Procópio, Paraná, 86300-000, Brazil. Tel.: +433133-3790; E-mail: ; Gustavo Isaza, Systems and Informatics Department, Center for Technology Development - Bioprocess and Agro-industry Plant, Universidad de Caldas, St 65 #26-10, Manizales, Colombia. Tel.: +57(606)8781500 ext 13146; E-mail: , Romain Guyot, IRD, 911 Av. Agropolis, 34394 Montpellier, France. Tel.: +334674160000; E-mail:
| | - Romain Guyot
- Corresponding authors. Simon Orozco-Arias, Computer Science Department, Universidad Autónoma de Manizales, Antigua Estación del Ferrocarrill, Manizalez, Colombia. Tel.: +57(606)8727272 - 8727709 Ext 102; E-mail: ; Alexandre Rossi Paschoal, Department of Computer Science, Bioinformatics and Pattern Recognition Group, Graduation Program in Bioinformatics, Federal University of Technology - Paraná, UTFPR, Cornélio Procópio, Paraná, 86300-000, Brazil. Tel.: +433133-3790; E-mail: ; Gustavo Isaza, Systems and Informatics Department, Center for Technology Development - Bioprocess and Agro-industry Plant, Universidad de Caldas, St 65 #26-10, Manizales, Colombia. Tel.: +57(606)8781500 ext 13146; E-mail: , Romain Guyot, IRD, 911 Av. Agropolis, 34394 Montpellier, France. Tel.: +334674160000; E-mail:
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3
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Nedoluzhko A, Sharko F, Tsygankova S, Boulygina E, Slobodova N, Teslyuk A, Galindo-Villegas J, Rastorguev S. Intergeneric hybridization of two stickleback species leads to introgression of membrane-associated genes and invasive TE expansion. Front Genet 2022; 13:863547. [PMID: 36092944 PMCID: PMC9452749 DOI: 10.3389/fgene.2022.863547] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 07/20/2022] [Indexed: 12/03/2022] Open
Abstract
Interspecific hybridization has occurred relatively frequently during the evolution of vertebrates. This process usually abolishes reproductive isolation between the parental species. Moreover, it results in the exchange of genetic material and can lead to hybridogenic speciation. Hybridization between species has predominately been observed at the interspecific level, whereas intergeneric hybridization is rarer. Here, using whole-genome sequencing analysis, we describe clear and reliable signals of intergeneric introgression between the three-spined stickleback (Gasterosteus aculeatus) and its distant mostly freshwater relative the nine-spined stickleback (Pungitius pungitius) that inhabit northwestern Russia. Through comparative analysis, we demonstrate that such introgression phenomena apparently take place in the moderate-salinity White Sea basin, although it is not detected in Japanese sea stickleback populations. Bioinformatical analysis of the sites influenced by introgression showed that they are located near transposable elements, whereas those in protein-coding sequences are mostly found in membrane-associated and alternative splicing-related genes.
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Affiliation(s)
- Artem Nedoluzhko
- Paleogenomics Laboratory, European University at Saint Petersburg, Saint Petersburg, Russia
- Limited Liability Company ELGENE, Moscow, Russia
| | - Fedor Sharko
- Limited Liability Company ELGENE, Moscow, Russia
- Laboratory of Vertebrate Genomics and Epigenomics, Research Center of Biotechnology of the Russian Academy of Sciences, Moscow, Russia
- Laboratory of Bioinformatics and Big Data Analysis, Kurchatov Center for Genomic Research, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Svetlana Tsygankova
- Laboratory of Eukaryotic Genomics, Kurchatov Center for Genomic Research, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Eugenia Boulygina
- Laboratory of Eukaryotic Genomics, Kurchatov Center for Genomic Research, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Natalia Slobodova
- Laboratory of Eukaryotic Genomics, Kurchatov Center for Genomic Research, National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Anton Teslyuk
- National Research Center “Kurchatov Institute”, Moscow, Russia
| | - Jorge Galindo-Villegas
- Faculty of Biosciences and Aquaculture, Nord University, Bodø, Norway
- *Correspondence: Jorge Galindo-Villegas, ; Sergey Rastorguev,
| | - Sergey Rastorguev
- Limited Liability Company ELGENE, Moscow, Russia
- Laboratory of Bioinformatics and Big Data Analysis, Kurchatov Center for Genomic Research, National Research Center “Kurchatov Institute”, Moscow, Russia
- *Correspondence: Jorge Galindo-Villegas, ; Sergey Rastorguev,
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4
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Ibrahim MA, Al-Shomrani BM, Simenc M, Alharbi SN, Alqahtani FH, Al-Fageeh MB, Manee MM. Comparative analysis of transposable elements provides insights into genome evolution in the genus Camelus. BMC Genomics 2021; 22:842. [PMID: 34800971 PMCID: PMC8605555 DOI: 10.1186/s12864-021-08117-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 10/23/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Transposable elements (TEs) are common features in eukaryotic genomes that are known to affect genome evolution critically and to play roles in gene regulation. Vertebrate genomes are dominated by TEs, which can reach copy numbers in the hundreds of thousands. To date, details regarding the presence and characteristics of TEs in camelid genomes have not been made available. RESULTS We conducted a genome-wide comparative analysis of camelid TEs, focusing on the identification of TEs and elucidation of transposition histories in four species: Camelus dromedarius, C. bactrianus, C. ferus, and Vicugna pacos. Our TE library was created using both de novo structure-based and homology-based searching strategies ( https://github.com/kacst-bioinfo-lab/TE_ideintification_pipeline ). Annotation results indicated a similar proportion of each genomes comprising TEs (35-36%). Class I LTR retrotransposons comprised 16-20% of genomes, and mostly consisted of the endogenous retroviruses (ERVs) groups ERVL, ERVL-MaLR, ERV_classI, and ERV_classII. Non-LTR elements comprised about 12% of genomes and consisted of SINEs (MIRs) and the LINE superfamilies LINE1, LINE2, L3/CR1, and RTE clades. Least represented were the Class II DNA transposons (2%), consisting of hAT-Charlie, TcMar-Tigger, and Helitron elements and comprising about 1-2% of each genome. CONCLUSIONS The findings of the present study revealed that the distribution of transposable elements across camelid genomes is approximately similar. This investigation presents a characterization of TE content in four camelid to contribute to developing a better understanding of camelid genome architecture and evolution.
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Affiliation(s)
- Mohanad A Ibrahim
- National Center for Bioinformatics, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Badr M Al-Shomrani
- National Center for Bioinformatics, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Mathew Simenc
- Department of Biological Sciences, California State University, Fullerton, USA
| | - Sultan N Alharbi
- National Center for Bioinformatics, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Fahad H Alqahtani
- National Center for Bioinformatics, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Mohamed B Al-Fageeh
- Life Sciences and Environment Research Institute, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia
| | - Manee M Manee
- National Center for Bioinformatics, King Abdulaziz City for Science and Technology, Riyadh, Saudi Arabia.
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5
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Su Y, Huang Q, Wang Z, Wang T. High genetic and epigenetic variation of transposable elements: Potential drivers to rapid adaptive evolution for the noxious invasive weed Mikania micrantha. Ecol Evol 2021; 11:13501-13517. [PMID: 34646486 PMCID: PMC8495827 DOI: 10.1002/ece3.8075] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 08/12/2021] [Accepted: 08/17/2021] [Indexed: 12/26/2022] Open
Abstract
Why invasive species can rapidly adapt to novel environments is a puzzling question known as the genetic paradox of invasive species. This paradox is explainable in terms of transposable elements (TEs) activity, which are theorized to be powerful mutational forces to create genetic variation. Mikania micrantha, a noxious invasive weed, in this sense provides an excellent opportunity to test the explanation. The genetic and epigenetic variation of 21 invasive populations of M. micrantha in southern China have been examined by using transposon display (TD) and transposon methylation display (TMD) techniques to survey 12 TE superfamilies. Our results showed that M. micrantha populations maintained an almost equally high level of TE-based genetic and epigenetic variation and they have been differentiated into subpopulations genetically and epigenetically. A similar positive spatial genetic and epigenetic structure pattern was observed within 300 m. Six and seven TE superfamilies presented significant genetic and epigenetic isolation by distance (IBD) pattern. In total, 59 genetic and 86 epigenetic adaptive TE loci were identified. Of them, 51 genetic and 44 epigenetic loci were found to correlate with 25 environmental variables (including precipitation, temperature, vegetation coverage, and soil metals). Twenty-five transposon-inserted genes were sequenced and homology-based annotated, which are found to be involved in a variety of molecular and cellular functions. Our research consolidates the importance of TE-associated genetic and epigenetic variation in the rapid adaptation and invasion of M. micrantha.
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Affiliation(s)
- Yingjuan Su
- School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
- Research Institute of Sun Yat‐sen UniversityShenzhenChina
| | - Qiqi Huang
- School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Zhen Wang
- School of Life SciencesSun Yat‐sen UniversityGuangzhouChina
| | - Ting Wang
- College of Life SciencesSouth China Agricultural UniversityGuangzhouChina
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Lebenzon JE, Torson AS, Sinclair BJ. Diapause differentially modulates the transcriptomes of fat body and flight muscle in the Colorado potato beetle. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2021; 40:100906. [PMID: 34509173 DOI: 10.1016/j.cbd.2021.100906] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/05/2021] [Accepted: 08/21/2021] [Indexed: 12/21/2022]
Abstract
Many temperate insects, such as the Colorado potato beetle, enter diapause in winter, during which they arrest their development, suppress their metabolic rate and have high stress tolerance. Diapause phenotypes can be transcriptionally regulated, however many studies to date report only whole animal gene expression rather than tissue-specific processes during diapause. We used RNA-seq to measure gene expression in fat body and flight muscle of diapausing and non-diapausing beetles. We used differential expression and GO enrichment analyses to evaluate longstanding hypotheses about the mechanisms that drive arrested development, changes in energy metabolism, and increased stress tolerance during diapause. We found evidence of G2/M cell cycle arrest, juvenile hormone catabolism, increased antioxidant metabolism, epigenetic modification, transposable element regulation, and cytoskeletal remodeling in both the fat body and flight muscle of diapausing beetles. Beetles differentially modulated the fat body and flight muscle transcriptomes during diapause with fat body playing a larger role in the hypoxia response and immunity, whereas flight muscle had higher abundance of transcripts related to the chaperone response and proteostasis. Our transcriptome provides evidence for distinct roles and responses of fat body and flight muscle during diapause in the Colorado potato beetle, and we provide testable hypotheses for biological processes that appear to drive diapause phenotypes in insects.
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Affiliation(s)
- Jacqueline E Lebenzon
- Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada.
| | - Alex S Torson
- Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada.
| | - Brent J Sinclair
- Department of Biology, University of Western Ontario, 1151 Richmond Street N, London, ON N6A 3K7, Canada.
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7
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Thieme M, Roulin AC. Identification of Active Transposable Elements in Plants: The Mobilome-Seq Approach. Methods Mol Biol 2021; 2250:95-102. [PMID: 33900595 DOI: 10.1007/978-1-0716-1134-0_8] [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: 04/18/2023]
Abstract
Transposable elements (TEs) are the main component of eukaryotic genomes. Besides their impact on genome size, TEs are also functionally important as they can alter gene expression and influence phenotypic variation. In plants, most top-down studies focus on extremely clear phenotypes such as the shape or the color of individuals and do not explore fully the role of TEs in evolution. Assessing the impact of TEs in a more systematic manner, however, requires identifying active TEs to further study their impact on phenotypes. In this chapter, we describe an in planta approach that consists in activating TEs by interfering with pathways involved in their silencing. It enables to directly investigate the functional impact of single TE families at low cost.
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Affiliation(s)
- Michael Thieme
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Anne C Roulin
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.
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8
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Flores-Ferrer A, Nguyen A, Glémin S, Deragon JM, Panaud O, Gourbière S. The ecology of the genome and the dynamics of the biological dark matter. J Theor Biol 2021; 518:110641. [PMID: 33640450 DOI: 10.1016/j.jtbi.2021.110641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 12/28/2020] [Accepted: 02/11/2021] [Indexed: 11/29/2022]
Abstract
Transposable elements (TEs) are essential components of the eukaryotic genomes. While mostly deleterious, evidence is mounting that TEs provide the host with beneficial adaptations. How 'selfish' or 'parasitic' DNA persists until it helps species evolution is emerging as a major evolutionary puzzle, especially in asexual taxa where the lack of sex strongly impede the spread of TEs. Since occasional but unchecked TE proliferations would ultimately drive host lineages toward extinction, asexual genomes are typically predicted to be free of TEs, which contrasts with their persistence in asexual taxa. We designed innovative 'Eco-genomic' models that account for both host demography and within-host molecular mechanisms of transposition and silencing to analyze their impact on TE dynamics in asexual genome populations. We unraveled that the spread of TEs can be limited to a stable level by density-dependent purifying selection when TE copies are over-dispersed among lineages and the host demographic turn-over is fast. We also showed that TE silencing can protect host populations in two ways; by preventing TEs with weak effects to accumulate or by favoring the elimination of TEs with large effects. Our predictions may explain TE persistence in known asexual taxa that typically show fast demography and where TE copy number variation between lineages is expected. Such TE persistence in asexual taxa potentially has important implications for their evolvability and the preservation of sexual reproduction.
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Affiliation(s)
- Alheli Flores-Ferrer
- UMR5096 'Laboratoire Génome et Développement des Plantes', Université de Perpignan Via Domitia, Perpignan, France.
| | - Anne Nguyen
- UMR5096 'Laboratoire Génome et Développement des Plantes', Université de Perpignan Via Domitia, Perpignan, France.
| | - Sylvain Glémin
- UMR 6553 'Ecosystèmes, Biodiversité, Evolution', Université de Rennes 1, Rennes, France.
| | - Jean-Marc Deragon
- UMR5096 'Laboratoire Génome et Développement des Plantes', Université de Perpignan Via Domitia, Perpignan, France.
| | - Olivier Panaud
- UMR5096 'Laboratoire Génome et Développement des Plantes', Université de Perpignan Via Domitia, Perpignan, France.
| | - Sébastien Gourbière
- UMR5096 'Laboratoire Génome et Développement des Plantes', Université de Perpignan Via Domitia, Perpignan, France; Centre for the Study of Evolution, School of Life Sciences, University of Sussex, Brighton BN1 9QG, United Kingdom.
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9
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Wyler M, Stritt C, Walser JC, Baroux C, Roulin AC. Impact of Transposable Elements on Methylation and Gene Expression across Natural Accessions of Brachypodium distachyon. Genome Biol Evol 2020; 12:1994-2001. [PMID: 32853352 PMCID: PMC7643609 DOI: 10.1093/gbe/evaa180] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/22/2020] [Indexed: 12/25/2022] Open
Abstract
Transposable elements (TEs) constitute a large fraction of plant genomes and are mostly present in a transcriptionally silent state through repressive epigenetic modifications, such as DNA methylation. TE silencing is believed to influence the regulation of adjacent genes, possibly as DNA methylation spreads away from the TE. Whether this is a general principle or a context-dependent phenomenon is still under debate, pressing for studying the relationship between TEs, DNA methylation, and nearby gene expression in additional plant species. Here, we used the grass Brachypodium distachyon as a model and produced DNA methylation and transcriptome profiles for 11 natural accessions. In contrast to what is observed in Arabidopsis thaliana, we found that TEs have a limited impact on methylation spreading and that only few TE families are associated with a low expression of their adjacent genes. Interestingly, we found that a subset of TE insertion polymorphisms is associated with differential gene expression across accessions. Thus, although not having a global impact on gene expression, distinct TE insertions may contribute to specific gene expression patterns in B. distachyon.
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Affiliation(s)
- Michele Wyler
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
| | - Christoph Stritt
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
| | | | - Célia Baroux
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
| | - Anne C Roulin
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
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10
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Phan NT, Orjuela J, Danchin EGJ, Klopp C, Perfus‐Barbeoch L, Kozlowski DK, Koutsovoulos GD, Lopez‐Roques C, Bouchez O, Zahm M, Besnard G, Bellafiore S. Genome structure and content of the rice root-knot nematode ( Meloidogyne graminicola). Ecol Evol 2020; 10:11006-11021. [PMID: 33144944 PMCID: PMC7593179 DOI: 10.1002/ece3.6680] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 07/04/2020] [Accepted: 07/17/2020] [Indexed: 12/15/2022] Open
Abstract
Discovered in the 1960s, Meloidogyne graminicola is a root-knot nematode species considered as a major threat to rice production. Yet, its origin, genomic structure, and intraspecific diversity are poorly understood. So far, such studies have been limited by the unavailability of a sufficiently complete and well-assembled genome. In this study, using a combination of Oxford Nanopore Technologies and Illumina sequencing data, we generated a highly contiguous reference genome (283 scaffolds with an N50 length of 294 kb, totaling 41.5 Mb). The completeness scores of our assembly are among the highest currently published for Meloidogyne genomes. We predicted 10,284 protein-coding genes spanning 75.5% of the genome. Among them, 67 are identified as possibly originating from horizontal gene transfers (mostly from bacteria), which supposedly contribute to nematode infection, nutrient processing, and plant defense manipulation. Besides, we detected 575 canonical transposable elements (TEs) belonging to seven orders and spanning 2.61% of the genome. These TEs might promote genomic plasticity putatively related to the evolution of M. graminicola parasitism. This high-quality genome assembly constitutes a major improvement regarding previously available versions and represents a valuable molecular resource for future phylogenomic studies of Meloidogyne species. In particular, this will foster comparative genomic studies to trace back the evolutionary history of M. graminicola and its closest relatives.
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Affiliation(s)
- Ngan Thi Phan
- IRD‐CIRAD‐University of MontpellierUMR Interactions Plantes Microorganismes Environnement (IPME)MontpellierFrance
| | - Julie Orjuela
- IRD‐CIRAD‐University of MontpellierUMR Interactions Plantes Microorganismes Environnement (IPME)MontpellierFrance
| | | | - Christophe Klopp
- Plateforme BioInfo GenotoulUR875INRAECastanet‐Tolosan cedexFrance
| | | | - Djampa K. Kozlowski
- Institut Sophia AgrobiotechINRAECNRSUniversité Côte d’AzurSophia AntipolisFrance
| | | | | | | | - Margot Zahm
- Plateforme BioInfo GenotoulUR875INRAECastanet‐Tolosan cedexFrance
| | | | - Stéphane Bellafiore
- IRD‐CIRAD‐University of MontpellierUMR Interactions Plantes Microorganismes Environnement (IPME)MontpellierFrance
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11
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Ghosh A, Platt RN, Vandewege MW, Tabassum R, Hsu CY, Isberg SR, Peterson DG, Finger JW, Kieran TJ, Glenn TC, Gongora J, Ray DA. Identification and characterization of microRNAs (miRNAs) and their transposable element origins in the saltwater crocodile, Crocodylus porosus. Anal Biochem 2020; 602:113781. [PMID: 32485163 DOI: 10.1016/j.ab.2020.113781] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 05/11/2020] [Accepted: 05/19/2020] [Indexed: 12/23/2022]
Abstract
MicroRNAs (miRNAs) are 18-24 nucleotide regulatory RNAs. They are involved in the regulation of genetic and biological pathways through post transcriptional gene silencing and/or translational repression. Data suggests a slow evolutionary rate for the saltwater crocodile (Crocodylus porosus) over the past several million years when compared to birds, the closest extant relatives of crocodilians. Understanding gene regulation in the saltwater crocodile in the context of relatively slow genomic change thus holds potential for the investigation of genomics, evolution, and adaptation. Utilizing eleven tissue types and sixteen small RNA libraries, we report 644 miRNAs in the saltwater crocodile with >78% of miRNAs being novel to crocodilians. We also identified potential targets for the miRNAs and analyzed the relationship of the miRNA repertoire to transposable elements (TEs). Results suggest an increased association of DNA transposons with miRNAs when compared to retrotransposons. This work reports the first comprehensive analysis of miRNAs in Crocodylus porosus and addresses the potential impacts of miRNAs in regulating the genome in the saltwater crocodile. In addition, the data suggests a supporting role of TEs as a source for miRNAs, adding to the increasing evidence that TEs play a significant role in the evolution of gene regulation.
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Affiliation(s)
- Arnab Ghosh
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Roy N Platt
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA
| | - Michael W Vandewege
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA; Department of Biology, Eastern New Mexico University, Portales, NM, USA
| | | | - Chuan-Yu Hsu
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, MS, USA
| | - Sally R Isberg
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, NSW, Australia; The Centre for Crocodile Research, Darwin, NT, Australia
| | - Daniel G Peterson
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, MS, USA
| | - John W Finger
- Department of Environmental Health Science, University of Georgia, Athens, GA, USA; Department of Biological Sciences, Auburn University, Auburn, AL, USA
| | - Troy J Kieran
- Department of Environmental Health Science, University of Georgia, Athens, GA, USA
| | - Travis C Glenn
- Department of Environmental Health Science, University of Georgia, Athens, GA, USA
| | - Jaime Gongora
- Sydney School of Veterinary Science, Faculty of Science, University of Sydney, Sydney, NSW, Australia
| | - David A Ray
- Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA.
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12
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Rastogi A, Vieira FRJ, Deton-Cabanillas AF, Veluchamy A, Cantrel C, Wang G, Vanormelingen P, Bowler C, Piganeau G, Hu H, Tirichine L. A genomics approach reveals the global genetic polymorphism, structure, and functional diversity of ten accessions of the marine model diatom Phaeodactylum tricornutum. THE ISME JOURNAL 2020; 14:347-363. [PMID: 31624346 PMCID: PMC6976637 DOI: 10.1038/s41396-019-0528-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/24/2019] [Accepted: 09/11/2019] [Indexed: 12/31/2022]
Abstract
Diatoms emerged in the Mesozoic period and presently constitute one of the main primary producers in the world's ocean and are of a major economic importance. In the current study, using whole genome sequencing of ten accessions of the model diatom Phaeodactylum tricornutum, sampled at broad geospatial and temporal scales, we draw a comprehensive landscape of the genomic diversity within the species. We describe strong genetic subdivisions of the accessions into four genetic clades (A-D) with constituent populations of each clade possessing a conserved genetic and functional makeup, likely a consequence of the limited dispersal of P. tricornutum in the open ocean. We further suggest dominance of asexual reproduction across all the populations, as implied by high linkage disequilibrium. Finally, we show limited yet compelling signatures of genetic and functional convergence inducing changes in the selection pressure on many genes and metabolic pathways. We propose these findings to have significant implications for understanding the genetic structure of diatom populations in nature and provide a framework to assess the genomic underpinnings of their ecological success and impact on aquatic ecosystems where they play a major role. Our work provides valuable resources for functional genomics and for exploiting the biotechnological potential of this model diatom species.
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Affiliation(s)
- Achal Rastogi
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
- Corteva Agriscience™, The V Ascendas, Atria Block, 12th Floor, Madhapur, Hyderabad, 500081, India
| | - Fabio Rocha Jimenez Vieira
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Anne-Flore Deton-Cabanillas
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Alaguraj Veluchamy
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
- Biological and Environmental Sciences and Engineering Division, Center for Desert Agriculture, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia
| | - Catherine Cantrel
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Gaohong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, China
| | - Pieter Vanormelingen
- Department of Biology, Research Group Protistology and Aquatic Ecology, Ghent University, Krijgslaan 281/S8 9000, Gent, Belgium
| | - Chris Bowler
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France
| | - Gwenael Piganeau
- Sorbonne Universités, UPMC Univ Paris 06, CNRS, Biologie Intégrative des Organismes Marins (BIOM), Observatoire Océanologique, F-66650, Banyuls/Mer, France
| | - Hanhua Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, 430072, Wuhan, China.
| | - Leila Tirichine
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole normale supérieure, CNRS, INSERM, PSL Université Paris, 75005, Paris, France.
- Université de Nantes, CNRS, UFIP, UMR 6286, F-44000, Nantes, France.
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13
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Zucchi MI, Cordeiro EMG, Allen C, Novello M, Viana JPG, Brown PJ, Manjunatha S, Omoto C, Pinheiro JB, Clough SJ. Patterns of Genome-Wide Variation, Population Differentiation and SNP Discovery of the Red Banded Stink Bug (Piezodorus guildinii). Sci Rep 2019; 9:14480. [PMID: 31597944 PMCID: PMC6785548 DOI: 10.1038/s41598-019-50999-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/09/2019] [Indexed: 01/05/2023] Open
Abstract
Unravelling the details of range expansion and ecological dominance shifts of insect pests has been challenging due to the lack of basic knowledge about population structure, gene flow, and most importantly, how natural selection is affecting the adaptive process. Piezodous guildinii is an emerging pest of soybean in the southern region of the United States, and increasingly important in Brazil in recent years. However, the reasons P. guildinii is gradually becoming more of a problem are questions still mostly unanswered. Here, we have genotyped P. guildinii samples and discovered 1,337 loci containing 4,083 variant sites SNPs that were used to estimate genetic structure and to identify gene candidates under natural selection. Our results revealed the existence of a significant genetic structure separating populations according to their broad geographic origin, i.e., U.S. and Brazil, supported by AMOVA (FGT = 0.26), STRUCTURE, PCA, and FST analyses. High levels of gene flow or coancestry within groups (i.e., within countries) can be inferred from the data, and no spatial pattern was apparent at the finer scale in Brazil. Samples from different seasons show more heterogeneous compositions suggesting mixed ancestry and a more complex dynamic. Lastly, we were able to detect and successfully annotated 123 GBS loci (10.5%) under positive selection. The gene ontology (GO) analysis implicated candidate genes under selection with genome reorganization, neuropeptides, and energy mobilization. We discuss how these findings could be related to recent outbreaks and suggest how new efforts directed to better understand P. guildinii population dynamics.
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Affiliation(s)
- Maria I Zucchi
- Institute of Biology, University of Campinas, Campinas, SP, Brazil
- Agência Paulista de Tecnologia dos Agronegócios, Pólo Regional Centro-Sul, Piracicaba, SP, Brazil
| | - Erick M G Cordeiro
- Department of Entomology and Acarology, University of Sao Paulo, Luiz de Queiroz College of Agriculture (USP/ESALQ), Piracicaba, SP, Brazil.
| | - Clint Allen
- US Department of Agriculture, Agricultural Research Service, Southern Insect Management Research Unit, Stoneville, MS, USA
| | - Mariana Novello
- Institute of Biology, University of Campinas, Campinas, SP, Brazil
| | | | - Patrick J Brown
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Shilpa Manjunatha
- US Department of Agriculture, Agricultural Research Service, Southern Insect Management Research Unit, Stoneville, MS, USA
| | - Celso Omoto
- Department of Entomology and Acarology, University of Sao Paulo, Luiz de Queiroz College of Agriculture (USP/ESALQ), Piracicaba, SP, Brazil
| | - José Baldin Pinheiro
- Department of Genetics, University of Sao Paulo, Luiz de Queiroz College of Agriculture (USP/ESALQ), Piracicaba, SP, Brazil
| | - Steven J Clough
- Department of Crop Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA
- US Department of Agriculture - Agricultural Research Service, Urbana, IL, USA
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14
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Orozco-Arias S, Isaza G, Guyot R. Retrotransposons in Plant Genomes: Structure, Identification, and Classification through Bioinformatics and Machine Learning. Int J Mol Sci 2019; 20:E3837. [PMID: 31390781 PMCID: PMC6696364 DOI: 10.3390/ijms20153837] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/31/2019] [Accepted: 08/02/2019] [Indexed: 01/26/2023] Open
Abstract
Transposable elements (TEs) are genomic units able to move within the genome of virtually all organisms. Due to their natural repetitive numbers and their high structural diversity, the identification and classification of TEs remain a challenge in sequenced genomes. Although TEs were initially regarded as "junk DNA", it has been demonstrated that they play key roles in chromosome structures, gene expression, and regulation, as well as adaptation and evolution. A highly reliable annotation of these elements is, therefore, crucial to better understand genome functions and their evolution. To date, much bioinformatics software has been developed to address TE detection and classification processes, but many problematic aspects remain, such as the reliability, precision, and speed of the analyses. Machine learning and deep learning are algorithms that can make automatic predictions and decisions in a wide variety of scientific applications. They have been tested in bioinformatics and, more specifically for TEs, classification with encouraging results. In this review, we will discuss important aspects of TEs, such as their structure, importance in the evolution and architecture of the host, and their current classifications and nomenclatures. We will also address current methods and their limitations in identifying and classifying TEs.
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Affiliation(s)
- Simon Orozco-Arias
- Department of Computer Science, Universidad Autónoma de Manizales, Manizales 170001, Colombia
- Department of Systems and Informatics, Universidad de Caldas, Manizales 170001, Colombia
| | - Gustavo Isaza
- Department of Systems and Informatics, Universidad de Caldas, Manizales 170001, Colombia
| | - Romain Guyot
- Department of Electronics and Automatization, Universidad Autónoma de Manizales, Manizales 170001, Colombia.
- Institut de Recherche pour le Développement, CIRAD, University Montpellier, 34000 Montpellier, France.
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15
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Choudhury RR, Parisod C. Jumping genes: Genomic ballast or powerhouse of biological diversification. Mol Ecol 2019; 26:4587-4590. [PMID: 28949090 DOI: 10.1111/mec.14247] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Revised: 07/04/2017] [Accepted: 07/06/2017] [Indexed: 01/08/2023]
Abstract
Studying hybridization has the potential to elucidate challenging questions in evolutionary biology such as the nature of adaptive genetic variation and reproductive isolation. A growing body of work highlights that the merging of divergent genomes goes beyond the reshuffling of standing variation from related species and promotes mutations (Abbott et al., ). However, to what extent such genome instability generates evolutionary significant variation remains largely elusive. In this issue of Molecular Ecology, Dennenmoser et al. () report considerable dynamics of transposable elements (TEs) in a recent invasive fish species of hybrid origin (Cottus; Figure ). It adds to the recent examples from plants to support TE-specific genome variation following hybridization. Insights from early, as well as established, hybrids are largely coherent with increased TE activity, and this fish system thus represents an inspiring opportunity to further address the possible association between genome dynamics and "rapid evolution of hybrid species." This work based on genome (re)sequencing contrasts with prior transcriptomics or PCR-based studies of TEs and illustrates how unprecedented amount of information promises a better understanding of the multiple patterns of variation across eukaryotic genomes; provided that we get the better of methodological advances. As discussed here, unbiased assessment of TE variation from genome surveys indeed remains a challenge precluding firm conclusions to be reached about the evolutionary significance of TEs. Despite methodological and conceptual developments that appear necessary to unambiguously uncover the unexplored iceberg below the known tip, the role of coding genes vs. TEs in promoting adaptation and speciation might be clarified in a not so remote future.
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Affiliation(s)
| | - Christian Parisod
- Institute of Biology, University of Neuchâtel, Neuchâtel, Switzerland
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16
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Rogivue A, Choudhury RR, Zoller S, Joost S, Felber F, Kasser M, Parisod C, Gugerli F. Genome-wide variation in nucleotides and retrotransposons in alpine populations of Arabis alpina (Brassicaceae). Mol Ecol Resour 2019; 19:773-787. [PMID: 30636378 DOI: 10.1111/1755-0998.12991] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Revised: 12/14/2018] [Accepted: 12/17/2018] [Indexed: 02/01/2023]
Abstract
Advances in high-throughput sequencing have promoted the collection of reference genomes and genome-wide diversity. However, the assessment of genomic variation among populations has hitherto mainly been surveyed through single-nucleotide polymorphisms (SNPs) and largely ignored the often major fraction of genomes represented by transposable elements (TEs). Despite accumulating evidence supporting the evolutionary significance of TEs, comprehensive surveys remain scarce. Here, we sequenced the full genomes of 304 individuals of Arabis alpina sampled from four nearby natural populations to genotype SNPs as well as polymorphic long terminal repeat retrotransposons (polymorphic TEs; i.e., presence/absence of TE insertions at specific loci). We identified 291,396 SNPs and 20,548 polymorphic TEs, comparing their contributions to genomic diversity and divergence across populations. Few SNPs were shared among populations and overall showed high population-specific variation, whereas most polymorphic TEs segregated among populations. The genomic context of these two classes of variants further highlighted candidate adaptive loci having a putative impact on functional genes. In particular, 4.96% of the SNPs were identified as nonsynonymous or affecting start/stop codons. In contrast, 43% of the polymorphic TEs were present next to Arabis genes enriched in functional categories related to the regulation of reproduction and responses to biotic as well as abiotic stresses. This unprecedented data set, mapping variation gained from SNPs and complementary polymorphic TEs within and among populations, will serve as a rich resource for addressing microevolutionary processes shaping genome variation.
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Affiliation(s)
- Aude Rogivue
- WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
| | - Rimjhim R Choudhury
- University of Neuchâtel, Neuchâtel, Switzerland.,Institute of Plant Sciences, University of Berne, Bern, Switzerland
| | - Stefan Zoller
- Genetic Diversity Centre, ETH Zürich, Zürich, Switzerland
| | - Stéphane Joost
- Laboratory of Geographic Information Systems (LASIG), School of Architecture, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - François Felber
- University of Neuchâtel, Neuchâtel, Switzerland.,Musée et Jardins botaniques cantonaux, Lausanne, Switzerland
| | | | | | - Felix Gugerli
- WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
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17
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Choudhury RR, Rogivue A, Gugerli F, Parisod C. Impact of polymorphic transposable elements on linkage disequilibrium along chromosomes. Mol Ecol 2019; 28:1550-1562. [DOI: 10.1111/mec.15014] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 12/26/2018] [Indexed: 01/03/2023]
Affiliation(s)
| | - Aude Rogivue
- WSL Swiss Federal Research Institute Birmensdorf Switzerland
| | - Felix Gugerli
- WSL Swiss Federal Research Institute Birmensdorf Switzerland
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18
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Stritt C, Gordon SP, Wicker T, Vogel JP, Roulin AC. Recent Activity in Expanding Populations and Purifying Selection Have Shaped Transposable Element Landscapes across Natural Accessions of the Mediterranean Grass Brachypodium distachyon. Genome Biol Evol 2018; 10:304-318. [PMID: 29281015 PMCID: PMC5786231 DOI: 10.1093/gbe/evx276] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2017] [Indexed: 01/05/2023] Open
Abstract
Transposable element (TE) activity has emerged as a major cause of variation in genome size and structure among species. To what extent TEs contribute to genetic variation and divergence within species, however, is much less clear, mainly because population genomic data have so far only been available for the classical model organisms. In this study, we use the annual Mediterranean grass Brachypodium distachyon to investigate TE dynamics in natural populations. Using whole-genome sequencing data for 53 natural accessions, we identified more than 5,400 TE polymorphisms across the studied genomes. We found, first, that while population bottlenecks and expansions have shaped genetic diversity in B. distachyon, these events did not lead to lineage-specific activations of TE families, as observed in other species. Instead, the same families have been active across the species range and TE activity is homogeneous across populations, indicating the presence of conserved regulatory mechanisms. Second, almost half of the TE insertion polymorphisms are accession-specific, most likely because of recent activity in expanding populations and the action of purifying selection. And finally, although TE insertion polymorphisms are underrepresented in and around genes, more than 1,000 of them occur in genic regions and could thus contribute to functional divergence. Our study shows that while TEs in B. distachyon are “well-behaved” compared with TEs in other species with larger genomes, they are an abundant source of lineage-specific genetic variation and may play an important role in population divergence and adaptation.
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Affiliation(s)
- Christoph Stritt
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
| | - Sean P Gordon
- DOE Joint Genome Institute, Walnut Creek, California
| | - Thomas Wicker
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
| | - John P Vogel
- DOE Joint Genome Institute, Walnut Creek, California
| | - Anne C Roulin
- Institute for Plant and Microbial Biology, University of Zurich, Switzerland
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19
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Agrelius T, Dudycha JL, Morris JT. Global DNA cytosine methylation variation in Spartina alterniflora at North Inlet, SC. PLoS One 2018; 13:e0203230. [PMID: 30199541 PMCID: PMC6130869 DOI: 10.1371/journal.pone.0203230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2018] [Accepted: 08/16/2018] [Indexed: 11/26/2022] Open
Abstract
Spartina alterniflora, marsh grass, is a vegetative apomicticly-reproducing halophyte native to marshes along the east coast of the United States and invasive across the world. S. alterniflora provides many ecosystem services including, but not limited to, water filtration, habitats for invertebrates, and sediment retention. Widespread diebacks of longstanding marsh grass colonies launched extensive investigations into probable mechanisms leading to patchy diebacks. There is still current debate as to the causes of a marsh dieback but environmental stress is acknowledged as a constant. Spatial epigenetic variation could contribute to variation of stress susceptibility, but the scale and structure of epigenetic variation is unknown. The current study investigates patterns of epigenetic variation in a natural population of S. alterniflora. This study examines variation of global DNA methylation within and among clones of the marsh grass Spartina alterniflora using an ELISA-like microplate reaction and observed significant heterogeneity of global DNA methylation within and among clones of S. alterniflora across the North Inlet basin, as well as significant differences of global methylation between adults and sexually produced seedlings. The present study also characterized differences for plants in a section of the population that experienced an acute marsh dieback in the year 2001 and have subsequently recolonized, finding a significant positive correlation between cytosine methylation and time period of colonization. The significant heterogeneity of global DNA methylation both within and among clones observed within this natural population of S. alterniflora and potential impacts from hypersaline environments at North Inlet suggests the need for more in-depth epigenetic studies to fully understand DNA methylation within an ecological context. Future studies should consider the effects of varying saline conditions on both global DNA and gene specific methylation.
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Affiliation(s)
- Trenton Agrelius
- Belle W. Baruch Institute for Marine and Coastal Sciences, University of South Carolina, Columbia, South Carolina, United States of America
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
- * E-mail:
| | - Jeffry L. Dudycha
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
| | - James T. Morris
- Belle W. Baruch Institute for Marine and Coastal Sciences, University of South Carolina, Columbia, South Carolina, United States of America
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, United States of America
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20
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Ty3/Gypsy retrotransposons in the Pacific abalone Haliotis discus hannai: characterization and use for species identification in the genus Haliotis. Genes Genomics 2018; 40:177-187. [PMID: 29892921 DOI: 10.1007/s13258-017-0619-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Accepted: 10/05/2017] [Indexed: 01/08/2023]
Abstract
Transposable elements are highly abundant elements that are present in all eukaryotic species. Here, we present a molecular description of abalone retrotransposon (Abret) elements. The genome of Haliotis discus hannai contains 130 Abret elements which were all Ty3/Gypsy retrotransposons. The Ty1/Copia elements were absent in the H. discus hannai genome. Most of the elements were not complete due to sequence truncation or coding region decay. However, three elements Abret-296, Abret-935, and Abret-3259 had most of the canonical features of LTR (long terminal repeat)-retrotransposons. There were several reading frame shifts in Abret-935 and Abret-3259 elements. Surprisingly, phylogenetic analysis indicated that all of the elements belonged to the Osvaldo lineage. The sequence divergence between LTRs revealed that the Abret elements were mostly active within 2 million years ago. Abret elements were used as molecular markers in SSAP analyses, which allowed clear distinction of different species in the genus Haliotis. The polymorphic markers were converted into SCAR markers for use in species identification by simple PCR in the Haliotis genus.
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21
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Identification of transposons near predicted lncRNA and mRNA pools of Prunus mume using an integrative transposable element database constructed from Rosaceae plant genomes. Mol Genet Genomics 2018; 293:1301-1316. [PMID: 29804262 DOI: 10.1007/s00438-018-1449-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 05/17/2018] [Indexed: 12/30/2022]
Abstract
This study focused on the construction of a database of transposable elements (TEs) from Rosaceae plants, the third most economically important plant family in temperate regions, and its transcriptomics applications. The evolutionary effects of TEs on gene regulation have been explored, and TE insertions can be the molecular bases of changes in gene structure and function. However, a specific Rosaceae plant TE database (RPTEdb) is lacking. The genomes of several Rosaceae plants have been sequenced, providing the opportunity to mine TE data at a whole-genome level. Therefore, we constructed the RPTEdb, a collective and comprehensive database of 19,596 annotated TEs in the genomes of Rosaceae plants using previously described identification and annotation methods and published genome sequences. The user-friendly web-based database provides access to research tools through hyperlinks, including Browse, TE tree, tools, JBrowse, and search sections, and through the inputting of sequences on the main webpage. Next, we performed one advanced application in which TEs near predicted long non-coding RNA (lncRNA) and mRNA domains within white and red petal-tissue transcriptomes of Prunus mume 'Fuban Tiaozhi' were identified, revealing 16 TEs that overlapped or were near 16 differentially expressed lncRNA domains, and 54 TEs that overlapped or were near 54 differentially expressed mRNA domains, and the TEs' possible functions were also discussed. We believe that the RPTEdb will contribute to the understanding of TE roles in the structural, functional and evolutionary dynamics of Rosaceae plant genomes.
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22
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Herrera CM, Alonso C, Medrano M, Pérez R, Bazaga P. Transgenerational epigenetics: Inheritance of global cytosine methylation and methylation-related epigenetic markers in the shrub Lavandula latifolia. AMERICAN JOURNAL OF BOTANY 2018; 105:741-748. [PMID: 29727470 DOI: 10.1002/ajb2.1074] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 01/22/2018] [Indexed: 06/08/2023]
Abstract
PREMISE OF THE STUDY The ecological and evolutionary significance of natural epigenetic variation (i.e., not based on DNA sequence variants) variation will depend critically on whether epigenetic states are transmitted from parents to offspring, but little is known on epigenetic inheritance in nonmodel plants. METHODS We present a quantitative analysis of transgenerational transmission of global DNA cytosine methylation (= proportion of all genomic cytosines that are methylated) and individual epigenetic markers (= methylation status of anonymous MSAP markers) in the shrub Lavandula latifolia. Methods based on parent-offspring correlations and parental variance component estimation were applied to epigenetic features of field-growing plants ('maternal parents') and greenhouse-grown progenies. Transmission of genetic markers (AFLP) was also assessed for reference. KEY RESULTS Maternal parents differed significantly in global DNA cytosine methylation (range = 21.7-36.7%). Greenhouse-grown maternal families differed significantly in global methylation, and their differences were significantly related to maternal origin. Methylation-sensitive amplified polymorphism (MSAP) markers exhibited significant transgenerational transmission, as denoted by significant maternal variance component of marker scores in greenhouse families and significant mother-offspring correlations of marker scores. CONCLUSIONS Although transmission-related measurements for global methylation and MSAP markers were quantitatively lower than those for AFLP markers taken as reference, this study has revealed extensive transgenerational transmission of genome-wide global cytosine methylation and anonymous epigenetic markers in L. latifolia. Similarity of results for global cytosine methylation and epigenetic markers lends robustness to this conclusion, and stresses the value of considering both types of information in epigenetic studies of nonmodel plants.
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Affiliation(s)
- Carlos M Herrera
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 26, 41092, Sevilla, Spain
| | - Conchita Alonso
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 26, 41092, Sevilla, Spain
| | - Mónica Medrano
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 26, 41092, Sevilla, Spain
| | - Ricardo Pérez
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de La Cartuja, Consejo Superior de Investigaciones Científicas (CSIC)-Universidad de, Sevilla, Sevilla, Spain
| | - Pilar Bazaga
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avenida Américo Vespucio 26, 41092, Sevilla, Spain
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de Freitas Pereira M, Veneault-Fourrey C, Vion P, Guinet F, Morin E, Barry KW, Lipzen A, Singan V, Pfister S, Na H, Kennedy M, Egli S, Grigoriev I, Martin F, Kohler A, Peter M. Secretome Analysis from the Ectomycorrhizal Ascomycete Cenococcum geophilum. Front Microbiol 2018; 9:141. [PMID: 29487573 PMCID: PMC5816826 DOI: 10.3389/fmicb.2018.00141] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 01/22/2018] [Indexed: 11/21/2022] Open
Abstract
Cenococcum geophilum is an ectomycorrhizal fungus with global distribution in numerous habitats and associates with a large range of host species including gymnosperm and angiosperm trees. Moreover, C. geophilum is the unique ectomycorrhizal species within the clade Dothideomycetes, the largest class of Ascomycetes containing predominantly saprotrophic and many devastating phytopathogenic fungi. Recent studies highlight that mycorrhizal fungi, as pathogenic ones, use effectors in form of Small Secreted Proteins (SSPs) as molecular keys to promote symbiosis. In order to better understand the biotic interaction of C. geophilum with its host plants, the goal of this work was to characterize mycorrhiza-induced small-secreted proteins (MiSSPs) that potentially play a role in the ectomycorrhiza formation and functioning of this ecologically very important species. We combined different approaches such as gene expression profiling, genome localization and conservation of MiSSP genes in different C. geophilum strains and closely related species as well as protein subcellular localization studies of potential targets of MiSSPs in interacting plants using in tobacco leaf cells. Gene expression analyses of C. geophilum interacting with Pinus sylvestris (pine) and Populus tremula × Populus alba (poplar) showed that similar sets of genes coding for secreted proteins were up-regulated and only few were specific to each host. Whereas pine induced more carbohydrate active enzymes (CAZymes), the interaction with poplar induced the expression of specific SSPs. We identified a set of 22 MiSSPs, which are located in both, gene-rich, repeat-poor or gene-sparse, repeat-rich regions of the C. geophilum genome, a genome showing a bipartite architecture as seen for some pathogens but not yet for an ectomycorrhizal fungus. Genome re-sequencing data of 15 C. geophilum strains and two close relatives Glonium stellatum and Lepidopterella palustris were used to study sequence conservation of MiSSP-encoding genes. The 22 MiSSPs showed a high presence-absence polymorphism among the studied C. geophilum strains suggesting an evolution through gene gain/gene loss. Finally, we showed that six CgMiSSPs target four distinct sub-cellular compartments such as endoplasmic reticulum, plasma membrane, cytosol and tonoplast. Overall, this work presents a comprehensive analysis of secreted proteins and MiSSPs in different genetic level of C. geophilum opening a valuable resource to future functional analysis.
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Affiliation(s)
- Maíra de Freitas Pereira
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
- Swiss Federal Research Institute WSL, Forest Dynamics, Birmensdorf, Switzerland
| | - Claire Veneault-Fourrey
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
- Université de Lorraine, Unité Mixte de Recherche 1136 Interactions Arbres-Microorganismes, Vandoeuvre les Nancy, France
| | - Patrice Vion
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
| | - Fréderic Guinet
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
- Université de Lorraine, Unité Mixte de Recherche 1136 Interactions Arbres-Microorganismes, Vandoeuvre les Nancy, France
| | - Emmanuelle Morin
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
| | - Kerrie W. Barry
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Anna Lipzen
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Vasanth Singan
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Stephanie Pfister
- Swiss Federal Research Institute WSL, Forest Dynamics, Birmensdorf, Switzerland
| | - Hyunsoo Na
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Megan Kennedy
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Simon Egli
- Swiss Federal Research Institute WSL, Forest Dynamics, Birmensdorf, Switzerland
| | - Igor Grigoriev
- United States Department of Energy Joint Genome Institute, Walnut Creek, CA, United States
| | - Francis Martin
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
| | - Annegret Kohler
- Institut National de la Recherche Agronomique, Unité Mixte de Recherche 1136 Interactions Arbres, Microorganismes, Laboratoire D'excellence Recherches Avancés sur la Biologie de l'Arbre et les Ecosystémes Forestiers, Centre Institut National de la Recherche Agronomique-Lorraine, Champenoux, France
| | - Martina Peter
- Swiss Federal Research Institute WSL, Forest Dynamics, Birmensdorf, Switzerland
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24
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Alonso C, Pérez R, Bazaga P, Medrano M, Herrera CM. Within-plant variation in seed size and inflorescence fecundity is associated with epigenetic mosaicism in the shrub Lavandula latifolia (Lamiaceae). ANNALS OF BOTANY 2018; 121:153-160. [PMID: 29186299 PMCID: PMC5786237 DOI: 10.1093/aob/mcx140] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 11/02/2017] [Indexed: 05/30/2023]
Abstract
BACKGROUND AND AIMS Sub-individual variation in traits of homologous structures has multiple ecological consequences for individuals and populations. Assessing the evolutionary significance of such effects requires an improved knowledge of the mechanisms underlying within-plant phenotypic heterogeneity. The hypothesis that continuous within-plant variation in some phenotypic traits can be associated with epigenetic mosaicism was examined. METHODS Fifteen individuals of the long-lived, evergreen Mediterranean shrub Lavandula latifolia were studied. Five widely spaced 'modules', each consisting of a single inflorescence plus all its subtending basal leaves, were collected from each shrub. Genomic DNA was extracted from leaf samples and genome-wide cytosine methylation determined by reversed phase high-performance liquid chromatography (HPLC) with spectrofluorimetric detection. The number and mean mass of seeds produced were determined for each inflorescence. An assessment was made of whether (1) leaves from different modules in the same plant differed significantly in global DNA cytosine methylation, and (2) mosaicism in cytosine methylation contributed to explain variation across modules in number and size of seeds. KEY RESULTS Leaves from different modules in the same plant differed in global DNA cytosine methylation. The magnitude of epigenetic mosaicism was substantial, as the variance in DNA methylation among modules of the same shrub was greater than the variance between individuals. Number and mean mass of seeds produced by individual inflorescences varied within plants and were quadratically related to cytosine methylation of subtending leaves, with an optimum at an intermediate methylation level (approx. 25 %). CONCLUSIONS The results support a causal link between global cytosine methylation of leaves in a module and the size and numbers of seeds produced by the associated inflorescence. It is proposed that variation in global DNA methylation within L. latifolia shrubs may result from the concerted action of plant sectoriality and differential exposure of different plant parts to some environmental factor(s) with a capacity to induce durable epigenetic changes.
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Affiliation(s)
- Conchita Alonso
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio, Sevilla, Spain
| | - Ricardo Pérez
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de La Cartuja, CSIC-US, Avda. Américo Vespucio, Sevilla, Spain
| | - Pilar Bazaga
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio, Sevilla, Spain
| | - Mónica Medrano
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio, Sevilla, Spain
| | - Carlos M Herrera
- Estación Biológica de Doñana, Consejo Superior de Investigaciones Científicas (CSIC), Avda. Américo Vespucio, Sevilla, Spain
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25
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Dennenmoser S, Sedlazeck FJ, Iwaszkiewicz E, Li X, Altmüller J, Nolte AW. Copy number increases of transposable elements and protein-coding genes in an invasive fish of hybrid origin. Mol Ecol 2017; 26:4712-4724. [PMID: 28390096 PMCID: PMC5638112 DOI: 10.1111/mec.14134] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Revised: 03/23/2017] [Accepted: 03/27/2017] [Indexed: 12/25/2022]
Abstract
Evolutionary dynamics of structural genetic variation in lineages of hybrid origin is not well explored, although structural mutations may increase in controlled hybrid crosses. We therefore tested whether structural variants accumulate in a fish of recent hybrid origin, invasive Cottus, relative to both parental species Cottus rhenanus and Cottus perifretum. Copy-number variation in exons of 10,979 genes was assessed using comparative genome hybridization arrays. Twelve genes showed significantly higher copy numbers in invasive Cottus compared to both parents. This coincided with increased expression for three genes related to vision, detoxification and muscle development, suggesting possible gene dosage effects. Copy number increases of putative transposons were assessed by comparative mapping of genomic DNA reads against a de novo assembly of 1,005 repetitive elements. In contrast to exons, copy number increases of repetitive elements were common (20.7%) in invasive Cottus, whereas decrease was very rare (0.01%). Among the increased repetitive elements, 53.8% occurred at higher numbers in C. perifretum compared to C. rhenanus, while only 1.4% were more abundant in C. rhenanus. This implies a biased mutational process that amplifies genetic material from one ancestor. To assess the frequency of de novo mutations through hybridization, we screened 64 laboratory-bred F2 offspring between the parental species for copy-number changes at five candidate loci. We found no evidence for new structural variants, indicating that they are too rare to be detected given our sampling scheme. Instead, they must have accumulated over more generations than we observed in a controlled cross.
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Affiliation(s)
- Stefan Dennenmoser
- Department for Evolutionary GeneticsMax‐Planck Institute for Evolutionary BiologyPlönGermany
- Institute for BiologyCarl von Ossietzky University OldenburgOldenburgGermany
| | | | - Elzbieta Iwaszkiewicz
- Department for Evolutionary GeneticsMax‐Planck Institute for Evolutionary BiologyPlönGermany
| | - Xiang‐Yi Li
- Department of Evolutionary Biology and Environmental StudiesUniversity of ZurichZurichSwitzerland
| | - Janine Altmüller
- Cologne Center for Genomics, and Institute of Human GeneticsUniversity of CologneCologneGermany
| | - Arne W. Nolte
- Department for Evolutionary GeneticsMax‐Planck Institute for Evolutionary BiologyPlönGermany
- Institute for BiologyCarl von Ossietzky University OldenburgOldenburgGermany
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26
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Cakmak B, Marakli S, Gozukirmizi N. Sukkularetrotransposon movements in the human genome. BIOTECHNOL BIOTEC EQ 2017. [DOI: 10.1080/13102818.2017.1316684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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27
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Zhang Z, Kukita C, Humayun MZ, Saier MH. Environment-directed activation of the Escherichia coliflhDC operon by transposons. MICROBIOLOGY-SGM 2017; 163:554-569. [PMID: 28100305 DOI: 10.1099/mic.0.000426] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The flagellar system in Escherichia coli K12 is expressed under the control of the flhDC-encoded master regulator FlhDC. Transposition of insertion sequence (IS) elements to the upstream flhDC promoter region up-regulates transcription of this operon, resulting in a more rapid motility. Wang and Wood (ISME J 2011;5:1517-1525) provided evidence that insertion of IS5 into upstream activating sites occurs at higher rates in semi-solid agar media in which swarming behaviour is allowed as compared with liquid or solid media where swarming cannot occur. We confirm this conclusion and show that three IS elements, IS1, IS3 and IS5, transpose to multiple upstream sites within a 370 bp region of the flhDC operon control region. Hot spots for IS insertion correlate with positions of stress-induced DNA duplex destabilization (SIDD). We show that IS insertion occurs at maximal rates in 0.24 % agar, with rates decreasing dramatically with increasing or decreasing agar concentrations. In mixed cultures, we show that these mutations preferentially arise from the wild-type parent at frequencies of up to 3×10-3 cell-1 day-1 when the inoculated parental and co-existing IS-activated mutant cells are entering the stationary growth phase. We rigorously show that the apparent increased mutation frequencies cannot be accounted for by increased swimming or by increased growth under the selective conditions used. Thus, our data are consistent with the possibility that appropriate environmental conditions, namely those that permit but hinder flagellar rotation, result in the activation of a mutational pathway that involves IS element insertion upstream of the flhDC operon.
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Affiliation(s)
- Zhongge Zhang
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - Chika Kukita
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
| | - M Zafri Humayun
- Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers New Jersey Medical School, Newark, NJ 07101-1709, USA
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California at San Diego, La Jolla, CA 92093-0116, USA
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28
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Patterns of Evolutionary Trajectories and Domestication History within the Genus Hordeum Assessed by REMAP Markers. J Mol Evol 2017; 84:116-128. [PMID: 28168328 DOI: 10.1007/s00239-016-9779-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Accepted: 12/29/2016] [Indexed: 10/20/2022]
Abstract
The patterns of genetic diversity related to the taxonomy and domestication history of 85 accessions representing the main four species of the genus Hordeum were examined by retrotransposon-microsatellite amplified polymorphism (REMAP) markers based on the retrotransposon BARE-1. A substantial level of genetic polymorphisms at among- and within-species level was observed showing that this retrotransposon family and its adjacent genomic regions has been a target for genome dynamics during the evolution and domestication of barley. The obtained data are consistent with the current taxonomic status within the genus Hordeum. Similar level of genetic diversity was observed between the wild and the domesticated barley accessions suggesting that transposable elements` activity and accumulation may counteract the decrease of genome-wide diversity following domestication. In addition, eco-geographical sub-genome pools of the cultivated barley were identified in support to the theory of multiple origins of domestication within the genus Hordeum. We also provide conclusions about the relationship between accessions of different species and the putative routes of barley domestication. In conclusion, the retrotransposon BARE-1 stands as a reliable and perspective DNA marker for the assessment of the phylogenetic and domestication history in the genus Hordeum and other crop species.
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29
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Kalinka A, Achrem M, Poter P. The DNA methylation level against the background of the genome size and t-heterochromatin content in some species of the genus Secale L. PeerJ 2017; 5:e2889. [PMID: 28149679 PMCID: PMC5267573 DOI: 10.7717/peerj.2889] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 12/08/2016] [Indexed: 01/05/2023] Open
Abstract
Methylation of cytosine in DNA is one of the most important epigenetic modifications in eukaryotes and plays a crucial role in the regulation of gene activity and the maintenance of genomic integrity. DNA methylation and other epigenetic mechanisms affect the development, differentiation or the response of plants to biotic and abiotic stress. This study compared the level of methylation of cytosines on a global (ELISA) and genomic scale (MSAP) between the species of the genus Secale. We analyzed whether the interspecific variation of cytosine methylation was associated with the size of the genome (C-value) and the content of telomeric heterochromatin. MSAP analysis showed that S. sylvestre was the most distinct species among the studied rye taxa; however, the results clearly indicated that these differences were not statistically significant. The total methylation level of the studied loci was very similar in all taxa and ranged from 60% in S. strictum ssp. africanum to 66% in S. cereale ssp. segetale, which confirmed the lack of significant differences in the sequence methylation pattern between the pairs of rye taxa. The level of global cytosine methylation in the DNA was not significantly associated with the content of t-heterochromatin and did not overlap with the existing taxonomic rye relationships. The highest content of 5-methylcytosine was found in S. cereale ssp. segetale (83%), while very low in S. strictum ssp. strictum (53%), which was significantly different from the methylation state of all taxa, except for S. sylvestre. The other studied taxa of rye had a similar level of methylated cytosine ranging from 66.42% (S. vavilovii) to 74.41% in (S. cereale ssp. afghanicum). The results obtained in this study are evidence that the percentage of methylated cytosine cannot be inferred solely based on the genome size or t-heterochromatin. This is a significantly more complex issue.
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Affiliation(s)
- Anna Kalinka
- Department of Cell Biology, Faculty of Biology, University of Szczecin, Szczecin, Poland; Molecular Biology and Biotechnology Center, Faculty of Biology, University of Szczecin, Szczecin, Poland
| | - Magdalena Achrem
- Department of Cell Biology, Faculty of Biology, University of Szczecin, Szczecin, Poland; Molecular Biology and Biotechnology Center, Faculty of Biology, University of Szczecin, Szczecin, Poland
| | - Paulina Poter
- Department of Cell Biology, Faculty of Biology, University of Szczecin , Szczecin , Poland
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30
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Parisod C. Profiling Transposable Elements and Their Epigenetic Effects in Non-model Species. Methods Mol Biol 2017; 1456:243-250. [PMID: 27770371 DOI: 10.1007/978-1-4899-7708-3_19] [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: 06/06/2023]
Abstract
Taking transposable elements into consideration in surveys of genetic and epigenetic variation remains challenging in species lacking a high-quality reference genome. Here, molecular techniques reducing genome complexity and specifically targeting restructuring and methylation changes in TE genome fractions are described. In particular, methyl-sensitive transposon display (MSTD) uses isoschizomers and PCR amplifications to assess the methylation environment of TE insertions. MSTD offers reliable insights into genome-wide epigenetic changes associated with TEs, especially when used together with similar techniques tracking random sequences.
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Affiliation(s)
- Christian Parisod
- Laboratory of Evolutionary Botany, Biology Institute, University of Neuchâtel, Rue Emile-Argand 11, 2009, Neuchâtel, Switzerland.
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31
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Ryan CP, Brownlie JC, Whyard S. Hsp90 and Physiological Stress Are Linked to Autonomous Transposon Mobility and Heritable Genetic Change in Nematodes. Genome Biol Evol 2016; 8:3794-3805. [PMID: 28082599 PMCID: PMC5521727 DOI: 10.1093/gbe/evw284] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2016] [Indexed: 12/21/2022] Open
Abstract
Transposable elements (TEs) have been recognized as potentially powerful drivers of genomic evolutionary change, but factors affecting their mobility and regulation remain poorly understood. Chaperones such as Hsp90 buffer environmental perturbations by regulating protein conformation, but are also part of the PIWI-interacting RNA pathway, which regulates genomic instability arising from mobile TEs in the germline. Stress-induced mutagenesis from TE movement could thus arise from functional trade-offs in the dual roles of Hsp90. We examined the functional constraints of Hsp90 and its role as a regulator of TE mobility by exposing nematodes (Caenorhabditis elegans and Caenorhabditis briggsae) to environmental stress, with and without RNAi-induced silencing of Hsp90. TE excision frequency increased with environmental stress intensity at multiple loci in several strains of each species. These effects were compounded by RNAi-induced knockdown of Hsp90. Mutation frequencies at the unc-22 marker gene in the offspring of animals exposed to environmental stress and Hsp90 RNAi mirrored excision frequency in response to these treatments. Our results support a role for Hsp90 in the suppression of TE mobility, and demonstrate that that the Hsp90 regulatory pathway can be overwhelmed with moderate environmental stress. By compromising genomic stability in germline cells, environmentally induced mutations arising from TE mobility and insertion can have permanent and heritable effects on both the phenotype and the genotype of subsequent generations.
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Affiliation(s)
- Calen P. Ryan
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Anthropology, Northwestern University, Evanston, IL
| | - Jeremy C. Brownlie
- School of Biomolecular and Physical Sciences, Griffith University, Brisbane, Queensland, Australia
| | - Steve Whyard
- Department of Biological Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
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32
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Negi P, Rai AN, Suprasanna P. Moving through the Stressed Genome: Emerging Regulatory Roles for Transposons in Plant Stress Response. FRONTIERS IN PLANT SCIENCE 2016; 7:1448. [PMID: 27777577 PMCID: PMC5056178 DOI: 10.3389/fpls.2016.01448] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2016] [Accepted: 09/12/2016] [Indexed: 05/02/2023]
Abstract
The recognition of a positive correlation between organism genome size with its transposable element (TE) content, represents a key discovery of the field of genome biology. Considerable evidence accumulated since then suggests the involvement of TEs in genome structure, evolution and function. The global genome reorganization brought about by transposon activity might play an adaptive/regulatory role in the host response to environmental challenges, reminiscent of McClintock's original 'Controlling Element' hypothesis. This regulatory aspect of TEs is also garnering support in light of the recent evidences, which project TEs as "distributed genomic control modules." According to this view, TEs are capable of actively reprogramming host genes circuits and ultimately fine-tuning the host response to specific environmental stimuli. Moreover, the stress-induced changes in epigenetic status of TE activity may allow TEs to propagate their stress responsive elements to host genes; the resulting genome fluidity can permit phenotypic plasticity and adaptation to stress. Given their predominating presence in the plant genomes, nested organization in the genic regions and potential regulatory role in stress response, TEs hold unexplored potential for crop improvement programs. This review intends to present the current information about the roles played by TEs in plant genome organization, evolution, and function and highlight the regulatory mechanisms in plant stress responses. We will also briefly discuss the connection between TE activity, host epigenetic response and phenotypic plasticity as a critical link for traversing the translational bridge from a purely basic study of TEs, to the applied field of stress adaptation and crop improvement.
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Affiliation(s)
| | | | - Penna Suprasanna
- Plant Stress Physiology and Biotechnology Section, Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research CentreTrombay, India
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33
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Long Terminal Repeat Retrotransposon Content in Eight Diploid Sunflower Species Inferred from Next-Generation Sequence Data. G3-GENES GENOMES GENETICS 2016; 6:2299-308. [PMID: 27233667 PMCID: PMC4978885 DOI: 10.1534/g3.116.029082] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The most abundant transposable elements (TEs) in plant genomes are Class I long terminal repeat (LTR) retrotransposons represented by superfamilies gypsy and copia. Amplification of these superfamilies directly impacts genome structure and contributes to differential patterns of genome size evolution among plant lineages. Utilizing short-read Illumina data and sequence information from a panel of Helianthus annuus (sunflower) full-length gypsy and copia elements, we explore the contribution of these sequences to genome size variation among eight diploid Helianthus species and an outgroup taxon, Phoebanthus tenuifolius. We also explore transcriptional dynamics of these elements in both leaf and bud tissue via RT-PCR. We demonstrate that most LTR retrotransposon sublineages (i.e., families) display patterns of similar genomic abundance across species. A small number of LTR retrotransposon sublineages exhibit lineage-specific amplification, particularly in the genomes of species with larger estimated nuclear DNA content. RT-PCR assays reveal that some LTR retrotransposon sublineages are transcriptionally active across all species and tissue types, whereas others display species-specific and tissue-specific expression. The species with the largest estimated genome size, H. agrestis, has experienced amplification of LTR retrotransposon sublineages, some of which have proliferated independently in other lineages in the Helianthus phylogeny.
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34
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Rey O, Danchin E, Mirouze M, Loot C, Blanchet S. Adaptation to Global Change: A Transposable Element-Epigenetics Perspective. Trends Ecol Evol 2016; 31:514-526. [PMID: 27080578 DOI: 10.1016/j.tree.2016.03.013] [Citation(s) in RCA: 109] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2015] [Revised: 03/11/2016] [Accepted: 03/14/2016] [Indexed: 12/21/2022]
Abstract
Understanding how organisms cope with global change is a major scientific challenge. The molecular pathways underlying rapid adaptive phenotypic responses to global change remain poorly understood. Here, we highlight the relevance of two environment-sensitive molecular elements: transposable elements (TEs) and epigenetic components (ECs). We first outline the sensitivity of these elements to global change stressors and review how they interact with each other. We then propose an integrative molecular engine coupling TEs and ECs and allowing organisms to fine-tune phenotypes in a real-time fashion, adjust the production of phenotypic and genetic variation, and produce heritable phenotypes with different levels of transmission fidelity. We finally discuss the implications of this molecular engine in the context of global change.
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Affiliation(s)
- Olivier Rey
- CNRS, UPS, Station d'Écologie Théorique et Expérimentale, UMR 5321, 09200 Moulis, France; Department of Biosciences, College of Science, Swansea University, Swansea SA2 8PP, UK.
| | - Etienne Danchin
- CNRS, UPS, ENFA, Évolution & Diversité Biologique (EDB) UMR 5174, 118 Route de Narbonne, 31062 Toulouse, Cedex 9, France; Université Paul Sabatier, Évolution & Diversité Biologique (EDB), 31062 Toulouse, Cedex 9, France
| | - Marie Mirouze
- Institut de Recherche pour le Développement, UMR232 DIADE Diversité Adaptation et Développement des Plantes, Laboratoire Génome et Développement des Plantes, 58 avenue Paul Alduy, 66860 Perpignan, France
| | - Céline Loot
- Institut Pasteur, Unité de Plasticité du Génome Bactérien, Paris, France; CNRS UMR3525, Paris, France
| | - Simon Blanchet
- CNRS, UPS, Station d'Écologie Théorique et Expérimentale, UMR 5321, 09200 Moulis, France; CNRS, UPS, ENFA, Évolution & Diversité Biologique (EDB) UMR 5174, 118 Route de Narbonne, 31062 Toulouse, Cedex 9, France.
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Senerchia N, Felber F, North B, Sarr A, Guadagnuolo R, Parisod C. Differential introgression and reorganization of retrotransposons in hybrid zones between wild wheats. Mol Ecol 2016; 25:2518-28. [DOI: 10.1111/mec.13515] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 11/24/2015] [Accepted: 11/30/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Natacha Senerchia
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchâtel; 2000 Neuchâtel Switzerland
| | - François Felber
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchâtel; 2000 Neuchâtel Switzerland
- Musée et Jardins Botaniques Cantonaux; 1007 Lausanne Switzerland
| | - Béatrice North
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchâtel; 2000 Neuchâtel Switzerland
| | - Anouk Sarr
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchâtel; 2000 Neuchâtel Switzerland
| | - Roberto Guadagnuolo
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchâtel; 2000 Neuchâtel Switzerland
| | - Christian Parisod
- Laboratory of Evolutionary Botany; Institute of Biology; University of Neuchâtel; 2000 Neuchâtel Switzerland
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36
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Yuzbasioglu G, Yilmaz S, Marakli S, Gozukirmizi N. Analysis ofHopi/Osr27andHouba/Tos5/Osr13retrotransposons in rice. BIOTECHNOL BIOTEC EQ 2016. [DOI: 10.1080/13102818.2015.1124026] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Senerchia N, Felber F, Parisod C. Genome reorganization in F1 hybrids uncovers the role of retrotransposons in reproductive isolation. Proc Biol Sci 2015; 282:20142874. [PMID: 25716787 DOI: 10.1098/rspb.2014.2874] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Interspecific hybridization leads to new interactions among divergent genomes, revealing the nature of genetic incompatibilities having accumulated during and after the origin of species. Conflicts associated with misregulation of transposable elements (TEs) in hybrids expectedly result in their activation and genome-wide changes that may be key to species boundaries. Repetitive genomes of wild wheats have diverged under differential dynamics of specific long terminal repeat retrotransposons (LTR-RTs), offering unparalleled opportunities to address the underpinnings of plant genome reorganization by selfish sequences. Using reciprocal F1 hybrids between three Aegilops species, restructuring and epigenetic repatterning was assessed at random and LTR-RT sequences with amplified fragment length polymorphism and sequence-specific amplified polymorphisms as well as their methylation-sensitive counterparts, respectively. Asymmetrical reorganization of LTR-RT families predicted to cause conflicting interactions matched differential survival of F1 hybrids. Consistent with the genome shock model, increasing divergence of merged LTR-RTs yielded higher levels of changes in corresponding genome fractions and lead to repeated reorganization of LTR-RT sequences in F1 hybrids. Such non-random reorganization of hybrid genomes is coherent with the necessary repression of incompatible TE loci in support of hybrid viability and indicates that TE-driven genomic conflicts may represent an overlooked factor supporting reproductive isolation.
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Affiliation(s)
- Natacha Senerchia
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland
| | - François Felber
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland Musée et Jardins Botaniques Cantonaux, Lausanne 1007, Switzerland
| | - Christian Parisod
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Rue Emile Argand 11, Neuchâtel 2000, Switzerland
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38
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Xiong TL, Xiao JH, Li YX, Bian SN, Huang DW. Diversity and evolution of Ty1-copia retroelements within Chalcidoidea by reverse transcriptase domain analysis. INSECT MOLECULAR BIOLOGY 2015; 24:503-516. [PMID: 26079156 DOI: 10.1111/imb.12167] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ty1-copia retrotransposons are widespread and diverse in insects. Some features of their hosts, such as mating and genetic systems, are predicted to influence the spread of selfish genetic elements like Ty1-copia. Using part of the reverse transcriptase gene as a reference, we experimentally surveyed Ty1-copia elements in eight species of fig wasps (Hymenoptera: Chalcidoidea), and performed an in silico analysis of six available genomes of chalcid wasps. Contrary to initial expectations that selfish elements such as Ty1-copia would be purged from the genomes of these species because of inbreeding and haplodiploidy, almost all of these wasps harbour an abundance of diverse Ty1-copia elements. Phylogenetic analyses suggest that the families of Ty1-copia elements found in these species have had a long association with their chalcid hosts. These results suggest an evolutionary scenario in which there was ancestral polymorphism followed by some taxa-specific events including stochastic loss and further diversification. Furthermore, estimating natural selection within the internal and terminal portions of the Ty1-copia phylogenies demonstrated that the elements are under strong evolutionary constraints for their long-term survival, but evolve like pseudogenes in the short term, accompanied by the rise and fall of parasitic elements in the history of wasp lineage.
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Affiliation(s)
- T-L Xiong
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - J-H Xiao
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Y-X Li
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - S-N Bian
- College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - D-W Huang
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
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Bardil A, Tayalé A, Parisod C. Evolutionary dynamics of retrotransposons following autopolyploidy in the Buckler Mustard species complex. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2015; 82:621-31. [PMID: 25823965 DOI: 10.1111/tpj.12837] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 03/18/2015] [Accepted: 03/23/2015] [Indexed: 05/21/2023]
Abstract
Long terminal repeat retrotransposons (LTR-RTs) represent a major fraction of plant genomes, but processes leading to transposition bursts remain elusive. Polyploidy expectedly leads to LTR-RT proliferation, as the merging of divergent diploids provokes a genome shock activating LTR-RTs and/or genetic redundancy supports the accumulation of active LTR-RTs through relaxation of selective constraints. Available evidence supports interspecific hybridization as the main trigger of genome dynamics, but few studies have addressed the consequences of intraspecific polyploidy (i.e. autopolyploidy), where the genome shock is expectedly minimized. The dynamics of LTR-RTs was thus here evaluated through low coverage 454 sequencing of three closely related diploid progenitors and three independent autotetraploids from the young Biscutella laevigata species complex. Genomes from this early diverging Brassicaceae lineage presented a minimum of 40% repeats and a large diversity of transposable elements. Differential abundances and patterns of sequence divergence among genomes for 37 LTR-RT families revealed contrasted dynamics during species diversification. Quiescent LTR-RT families with limited genetic variation among genomes were distinguished from active families (37.8%) having proliferated in specific taxa. Specific families proliferated in autopolyploids only, but most transpositionally active families in polyploids were also differentiated among diploids. Low expression levels of transpositionally active LTR-RT families in autopolyploids further supported that genome shock and redundancy are non-mutually exclusive triggers of LTR-RT proliferation. Although reputed stable, autopolyploid genomes show LTR-RT fractions presenting analogies with polyploids between widely divergent genomes.
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Affiliation(s)
- Amélie Bardil
- Laboratory of Evolutionary Botany, University of Neuchâtel, Neuchâtel, 2000, Switzerland
| | - Alexandre Tayalé
- Laboratory of Evolutionary Botany, University of Neuchâtel, Neuchâtel, 2000, Switzerland
| | - Christian Parisod
- Laboratory of Evolutionary Botany, University of Neuchâtel, Neuchâtel, 2000, Switzerland
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40
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Pavlicev M, Hiratsuka K, Swaggart KA, Dunn C, Muglia L. Detecting endogenous retrovirus-driven tissue-specific gene transcription. Genome Biol Evol 2015; 7:1082-97. [PMID: 25767249 PMCID: PMC4419796 DOI: 10.1093/gbe/evv049] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Transposable elements (TEs) comprise approximately half of the human genome, and several independent lines of investigation have demonstrated their role in rewiring gene expression during development, evolution, and oncogenesis. The identification of their regulatory effects has largely been idiosyncratic, by linking activity with isolated genes. Their distribution throughout the genome raises critical questions—do these elements contribute to broad tissue- and lineage-specific regulation? If so, in what manner, as enhancers, promoters, RNAs? Here, we devise a novel approach to systematically dissect the genome-wide consequences of TE insertion on gene expression, and test the hypothesis that classes of endogenous retrovirus long terminal repeats (LTRs) exert tissue-specific regulation of adjacent genes. Using correlation of expression patterns across 18 tissue types, we reveal the tissue-specific uncoupling of gene expression due to 62 different LTR classes. These patterns are specific to the retroviral insertion, as the same genes in species without the LTRs do not exhibit the same effect. Although the LTRs can be transcribed themselves, the most highly transcribed TEs do not have the largest effects on adjacent regulation of coding genes, suggesting they function predominantly as enhancers. Moreover, the tissue-specific patterns of gene expression that are detected by our method arise from a limited number of genes, rather than as a general consequence of LTR integration. These findings identify basic principles of co-opting LTRs for genome evolution, and support the utility of our method for the analysis of TE, or other specific gene sets, in relation to the rest of the genome.
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Affiliation(s)
- Mihaela Pavlicev
- Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine
| | - Kaori Hiratsuka
- Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine
| | - Kayleigh A Swaggart
- Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine
| | - Caitlin Dunn
- Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine
| | - Louis Muglia
- Center for Prevention of Preterm Birth, Perinatal Institute, Cincinnati Children's Hospital Medical Center and Department of Pediatrics, University of Cincinnati College of Medicine
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Renaut S, Rowe HC, Ungerer MC, Rieseberg LH. Genomics of homoploid hybrid speciation: diversity and transcriptional activity of long terminal repeat retrotransposons in hybrid sunflowers. Philos Trans R Soc Lond B Biol Sci 2015; 369:rstb.2013.0345. [PMID: 24958919 DOI: 10.1098/rstb.2013.0345] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Hybridization is thought to play an important role in plant evolution by introducing novel genetic combinations and promoting genome restructuring. However, surprisingly little is known about the impact of hybridization on transposable element (TE) proliferation and the genomic response to TE activity. In this paper, we first review the mechanisms by which homoploid hybrid species may arise in nature. We then present hybrid sunflowers as a case study to examine transcriptional activity of long terminal repeat retrotransposons in the annual sunflowers Helianthus annuus, Helianthus petiolaris and their homoploid hybrid derivatives (H. paradoxus, H. anomalus and H. deserticola) using high-throughput transcriptome sequencing technologies (RNAseq). Sampling homoploid hybrid sunflower taxa revealed abundant variation in TE transcript accumulation. In addition, genetic diversity for several candidate genes hypothesized to regulate TE activity was characterized. Specifically, we highlight one candidate chromatin remodelling factor gene with a direct role in repressing TE activity in a hybrid species. This paper shows that TE amplification in hybrid lineages is more idiosyncratic than previously believed and provides a first step towards identifying the mechanisms responsible for regulating and repressing TE expansions.
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Affiliation(s)
- Sebastien Renaut
- Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Heather C Rowe
- Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4
| | - Mark C Ungerer
- Division of Biology, Kansas State University, 426 Ackert Hall, Manhattan, KS 66506, USA
| | - Loren H Rieseberg
- Biodiversity Research Centre and Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z4 Department of Biology, Indiana University, 1001 East Third St., Bloomington, IN 47405, USA
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42
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Alonso C, Pérez R, Bazaga P, Herrera CM. Global DNA cytosine methylation as an evolving trait: phylogenetic signal and correlated evolution with genome size in angiosperms. Front Genet 2015; 6:4. [PMID: 25688257 PMCID: PMC4310347 DOI: 10.3389/fgene.2015.00004] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 01/07/2015] [Indexed: 01/17/2023] Open
Abstract
DNA cytosine methylation is a widespread epigenetic mechanism in eukaryotes, and plant genomes commonly are densely methylated. Genomic methylation can be associated with functional consequences such as mutational events, genomic instability or altered gene expression, but little is known on interspecific variation in global cytosine methylation in plants. In this paper, we compare global cytosine methylation estimates obtained by HPLC and use a phylogenetically-informed analytical approach to test for significance of evolutionary signatures of this trait across 54 angiosperm species in 25 families. We evaluate whether interspecific variation in global cytosine methylation is statistically related to phylogenetic distance and also whether it is evolutionarily correlated with genome size (C-value). Global cytosine methylation varied widely between species, ranging between 5.3% (Arabidopsis) and 39.2% (Narcissus). Differences between species were related to their evolutionary trajectories, as denoted by the strong phylogenetic signal underlying interspecific variation. Global cytosine methylation and genome size were evolutionarily correlated, as revealed by the significant relationship between the corresponding phylogenetically independent contrasts. On average, a ten-fold increase in genome size entailed an increase of about 10% in global cytosine methylation. Results show that global cytosine methylation is an evolving trait in angiosperms whose evolutionary trajectory is significantly linked to changes in genome size, and suggest that the evolutionary implications of epigenetic mechanisms are likely to vary between plant lineages.
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Affiliation(s)
| | - Ricardo Pérez
- Instituto de Investigaciones Químicas, Centro de Investigaciones Científicas Isla de La Cartuja, CSIC-US Sevilla, Spain
| | - Pilar Bazaga
- Estación Biológica de Doñana, CSIC Sevilla, Spain
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Roy NS, Choi JY, Lee SI, Kim NS. Marker utility of transposable elements for plant genetics, breeding, and ecology: a review. Genes Genomics 2014. [DOI: 10.1007/s13258-014-0252-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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44
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Senerchia N, Felber F, Parisod C. Contrasting evolutionary trajectories of multiple retrotransposons following independent allopolyploidy in wild wheats. THE NEW PHYTOLOGIST 2014; 202:975-985. [PMID: 24548250 DOI: 10.1111/nph.12731] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2013] [Accepted: 01/09/2014] [Indexed: 06/03/2023]
Abstract
Transposable elements (TEs) are expectedly central to genome evolution. To assess the impact of TEs in driving genome turnover, we used allopolyploid genomes, showing considerable deviation from the predicted additivity of their diploid progenitors and thus having undergone major restructuring. Genome survey sequencing was used to select 17 putatively active families of long terminal repeat retrotransposons. Genome-wide TE insertions were genotyped with sequence-specific amplified polymorphism (SSAP) in diploid progenitors and their derived polyploids, and compared with changes in random sequences to assess restructuring of four independent Aegilops allotetraploid genomes. Generally, TEs with different evolutionary trajectories from those of random sequences were identified. Thus, TEs presented family-specific and species-specific dynamics following polyploidy, as illustrated by Sabine showing proliferation in particular polyploids, but massive elimination in others. Contrasting with that, only a few families (BARE1 and Romani) showed proliferation in all polyploids. Overall, TE divergence between progenitors was strongly correlated with the degree of restructuring in polyploid TE fractions. TE families present evolutionary trajectories that are decoupled from genome-wide changes after allopolyploidy and have a pervasive impact on their restructuring.
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Affiliation(s)
- Natacha Senerchia
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
| | - François Felber
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
- Musée et Jardins botaniques cantonaux, Avenue de Cour 14bis, 1007, Lausanne, Switzerland
| | - Christian Parisod
- Laboratory of Evolutionary Botany, Institute of Biology, University of Neuchâtel, Rue Emile-Argand 11, 2000, Neuchâtel, Switzerland
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Genetics of cryptic speciation within an Arctic mustard, Draba nivalis. PLoS One 2014; 9:e93834. [PMID: 24691072 PMCID: PMC3972243 DOI: 10.1371/journal.pone.0093834] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2013] [Accepted: 03/09/2014] [Indexed: 01/13/2023] Open
Abstract
Crossing experiments indicate that hybrid sterility barriers frequently have developed within diploid, circumpolar plant species of the genus Draba. To gain insight into the rapid evolution of postzygotic reproductive isolation in this system, we augmented the linkage map of one of these species, D. nivalis, and searched for quantitative trait loci (QTLs) associated with reproductive isolation. The map adds 63 new dominant markers to a previously published dataset of 31 co-dominant microsatellites. These markers include 52 amplified fragment length polymorphisms (AFLPs) and 11 sequence-specific amplified polymorphisms (SSAPs) based on retrotransposon sequence. 22 markers displaying transmission ratio distortion were further included in the map. We resolved eight linkage groups with a total map length of 894 cM. Significant genotype-trait associations, or quantitative trait loci (QTL), were detected for reproductive phenotypes including pollen fertility (4 QTLs), seed set (3 QTLs), flowering time (3 QTLs) and number of flowers (4 QTLs). Observed patterns of inheritance were consistent with the influence of both nuclear-nuclear interactions and chromosomal changes on these traits. All seed set QTLs and one pollen fertility QTL displayed underdominant effects suggestive of the involvement of chromosomal rearrangements in hybrid sterility. Interestingly, D. nivalis is predominantly self-fertilizing, which may facilitate the establishment of underdominant loci and contribute to reproductive isolation.
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46
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Livingstone K, Vines T, Gow J. Editorial 2014. Mol Ecol Resour 2013; 14:1-6. [PMID: 24286559 DOI: 10.1111/1755-0998.12196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kevin Livingstone
- Department of Biology, Trinity University, One Trinity Place, San Antonio, TX, 78212-7200, USA.
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