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Merkulov P, Serganova M, Petrov G, Mityukov V, Kirov I. Long-read sequencing of extrachromosomal circular DNA and genome assembly of a Solanum lycopersicum breeding line revealed active LTR retrotransposons originating from S. Peruvianum L. introgressions. BMC Genomics 2024; 25:404. [PMID: 38658857 PMCID: PMC11044480 DOI: 10.1186/s12864-024-10314-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 04/15/2024] [Indexed: 04/26/2024] Open
Abstract
Transposable elements (TEs) are a major force in the evolution of plant genomes. Differences in the transposition activities and landscapes of TEs can vary substantially, even in closely related species. Interspecific hybridization, a widely employed technique in tomato breeding, results in the creation of novel combinations of TEs from distinct species. The implications of this process for TE transposition activity have not been studied in modern cultivars. In this study, we used nanopore sequencing of extrachromosomal circular DNA (eccDNA) and identified two highly active Ty1/Copia LTR retrotransposon families of tomato (Solanum lycopersicum), called Salsa and Ketchup. Elements of these families produce thousands of eccDNAs under controlled conditions and epigenetic stress. EccDNA sequence analysis revealed that the major parts of eccDNA produced by Ketchup and Salsa exhibited low similarity to the S. lycopersicum genomic sequence. To trace the origin of these TEs, whole-genome nanopore sequencing and de novo genome assembly were performed. We found that these TEs occurred in a tomato breeding line via interspecific introgression from S. peruvianum. Our findings collectively show that interspecific introgressions can contribute to both genetic and phenotypic diversity not only by introducing novel genetic variants, but also by importing active transposable elements from other species.
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Affiliation(s)
- Pavel Merkulov
- All-Russia Research Institute of Agricultural Biotechnology, 127550, Moscow, Russia
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia
| | - Melania Serganova
- All-Russia Research Institute of Agricultural Biotechnology, 127550, Moscow, Russia
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia
| | - Georgy Petrov
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia
| | - Vladislav Mityukov
- Skolkovo Institute of Science and Technology, 121205, Moscow, Russia
- Institute for Information Transmission Problems (Kharkevich Institute), Russian Academy of Sciences, 127051, Moscow, Russia
| | - Ilya Kirov
- All-Russia Research Institute of Agricultural Biotechnology, 127550, Moscow, Russia.
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia.
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2
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de Tomás C, Vicient CM. The Genomic Shock Hypothesis: Genetic and Epigenetic Alterations of Transposable Elements after Interspecific Hybridization in Plants. EPIGENOMES 2023; 8:2. [PMID: 38247729 PMCID: PMC10801548 DOI: 10.3390/epigenomes8010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 12/21/2023] [Accepted: 12/24/2023] [Indexed: 01/23/2024] Open
Abstract
Transposable elements (TEs) are major components of plant genomes with the ability to change their position in the genome or to create new copies of themselves in other positions in the genome. These can cause gene disruption and large-scale genomic alterations, including inversions, deletions, and duplications. Host organisms have evolved a set of mechanisms to suppress TE activity and counter the threat that they pose to genome integrity. These includes the epigenetic silencing of TEs mediated by a process of RNA-directed DNA methylation (RdDM). In most cases, the silencing machinery is very efficient for the vast majority of TEs. However, there are specific circumstances in which TEs can evade such silencing mechanisms, for example, a variety of biotic and abiotic stresses or in vitro culture. Hybridization is also proposed as an inductor of TE proliferation. In fact, the discoverer of the transposons, Barbara McClintock, first hypothesized that interspecific hybridization provides a "genomic shock" that inhibits the TE control mechanisms leading to the mobilization of TEs. However, the studies carried out on this topic have yielded diverse results, showing in some cases a total absence of mobilization or being limited to only some TE families. Here, we review the current knowledge about the impact of interspecific hybridization on TEs in plants and the possible implications of changes in the epigenetic mechanisms.
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Affiliation(s)
| | - Carlos M. Vicient
- Centre for Research in Agricultural Genomics, CRAG (CSIC-IRTA-UAB-UB), Campus UAB, Cerdanyola del Vallès, 08193 Barcelona, Spain
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3
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Bajus M, Macko-Podgórni A, Grzebelus D, Baránek M. A review of strategies used to identify transposition events in plant genomes. FRONTIERS IN PLANT SCIENCE 2022; 13:1080993. [PMID: 36531345 PMCID: PMC9751208 DOI: 10.3389/fpls.2022.1080993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Transposable elements (TEs) were initially considered redundant and dubbed 'junk DNA'. However, more recently they were recognized as an essential element of genome plasticity. In nature, they frequently become active upon exposition of the host to stress conditions. Even though most transposition events are neutral or even deleterious, occasionally they may happen to be beneficial, resulting in genetic novelty providing better fitness to the host. Hence, TE mobilization may promote adaptability and, in the long run, act as a significant evolutionary force. There are many examples of TE insertions resulting in increased tolerance to stresses or in novel features of crops which are appealing to the consumer. Possibly, TE-driven de novo variability could be utilized for crop improvement. However, in order to systematically study the mechanisms of TE/host interactions, it is necessary to have suitable tools to globally monitor any ongoing TE mobilization. With the development of novel potent technologies, new high-throughput strategies for studying TE dynamics are emerging. Here, we present currently available methods applied to monitor the activity of TEs in plants. We divide them on the basis of their operational principles, the position of target molecules in the process of transposition and their ability to capture real cases of actively transposing elements. Their possible theoretical and practical drawbacks are also discussed. Finally, conceivable strategies and combinations of methods resulting in an improved performance are proposed.
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Affiliation(s)
- Marko Bajus
- Mendeleum—Institute of Genetics, Faculty of Horticulture, Mendel University in Brno, Lednice, Czechia
| | - Alicja Macko-Podgórni
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Kraków, Poland
| | - Dariusz Grzebelus
- Department of Plant Biology and Biotechnology, Faculty of Biotechnology and Horticulture, University of Agriculture in Krakow, Kraków, Poland
| | - Miroslav Baránek
- Mendeleum—Institute of Genetics, Faculty of Horticulture, Mendel University in Brno, Lednice, Czechia
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4
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Li SF, She HB, Yang LL, Lan LN, Zhang XY, Wang LY, Zhang YL, Li N, Deng CL, Qian W, Gao WJ. Impact of LTR-Retrotransposons on Genome Structure, Evolution, and Function in Curcurbitaceae Species. Int J Mol Sci 2022; 23:ijms231710158. [PMID: 36077556 PMCID: PMC9456015 DOI: 10.3390/ijms231710158] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/02/2022] [Accepted: 09/02/2022] [Indexed: 11/17/2022] Open
Abstract
Long terminal repeat (LTR)-retrotransposons (LTR-RTs) comprise a major portion of many plant genomes and may exert a profound impact on genome structure, function, and evolution. Although many studies have focused on these elements in an individual species, their dynamics on a family level remains elusive. Here, we investigated the abundance, evolutionary dynamics, and impact on associated genes of LTR-RTs in 16 species in an economically important plant family, Cucurbitaceae. Results showed that full-length LTR-RT numbers and LTR-RT content varied greatly among different species, and they were highly correlated with genome size. Most of the full-length LTR-RTs were amplified after the speciation event, reflecting the ongoing rapid evolution of these genomes. LTR-RTs highly contributed to genome size variation via species-specific distinct proliferations. The Angela and Tekay lineages with a greater evolutionary age were amplified in Trichosanthes anguina, whereas a recent activity burst of Reina and another ancient round of Tekay activity burst were examined in Sechium edule. In addition, Tekay and Retand lineages belonging to the Gypsy superfamily underwent a recent burst in Gynostemma pentaphyllum. Detailed investigation of genes with intronic and promoter LTR-RT insertion showed diverse functions, but the term of metabolism was enriched in most species. Further gene expression analysis in G.pentaphyllum revealed that the LTR-RTs within introns suppress the corresponding gene expression, whereas the LTR-RTs within promoters exert a complex influence on the downstream gene expression, with the main function of promoting gene expression. This study provides novel insights into the organization, evolution, and function of LTR-RTs in Cucurbitaceae genomes.
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Affiliation(s)
- Shu-Fen Li
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Hong-Bing She
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
| | - Long-Long Yang
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Li-Na Lan
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Xin-Yu Zhang
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Li-Ying Wang
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Yu-Lan Zhang
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Ning Li
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Chuan-Liang Deng
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Wei Qian
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing 100081, China
- Correspondence: (W.Q.); (W.-J.G.)
| | - Wu-Jun Gao
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
- Correspondence: (W.Q.); (W.-J.G.)
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5
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de Tomás C, Bardil A, Castanera R, Casacuberta JM, Vicient CM. Absence of major epigenetic and transcriptomic changes accompanying an interspecific cross between peach and almond. HORTICULTURE RESEARCH 2022; 9:uhac127. [PMID: 35928404 PMCID: PMC9343919 DOI: 10.1093/hr/uhac127] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 05/24/2022] [Indexed: 06/15/2023]
Abstract
Hybridization has been widely used in breeding of cultivated species showing low genetic variability, such as peach (Prunus persica). The merging of two different genomes in a hybrid often triggers a so-called "genomic shock" with changes in DNA methylation and in the induction of transposable element expression and mobilization. Here, we analysed the DNA methylation and transcription levels of transposable elements and genes in leaves of Prunus persica and Prunus dulcis and in an F1 hybrid using high-throughput sequencing technologies. Contrary to the "genomic shock" expectations, we found that the overall levels of DNA methylation in the transposable elements in the hybrid are not significantly altered compared with those of the parental genomes. We also observed that the levels of transcription of the transposable elements in the hybrid are in most cases intermediate as compared with that of the parental species and we have not detected cases of higher transcription in the hybrid. We also found that the proportion of genes whose expression is altered in the hybrid compared with the parental species is low. The expression of genes potentially involved in the regulation of the activity of the transposable elements is not altered. We can conclude that the merging of the two parental genomes in this Prunus persica x Prunus dulcis hybrid does not result in a "genomic shock" with significant changes in the DNA methylation or in the transcription. The absence of major changes may facilitate using interspecific peach x almond crosses for peach improvement.
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Affiliation(s)
- Carlos de Tomás
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, Barcelona 08193, Spain
| | - Amélie Bardil
- Institut écologie et environnement (INEE), CNRS, Montpelier, France
| | - Raúl Castanera
- Centre for Research in Agricultural Genomics CSIC-IRTA-UAB-UB, Campus UAB, Edifici CRAG, Bellaterra, Barcelona 08193, Spain
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6
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Gantuz M, Morales A, Bertoldi MV, Ibañez VN, Duarte PF, Marfil CF, Masuelli RW. Hybridization and polyploidization effects on LTR-retrotransposon activation in potato genome. JOURNAL OF PLANT RESEARCH 2022; 135:81-92. [PMID: 34674075 DOI: 10.1007/s10265-021-01354-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Hybridization and polyploidization are major forces in plant evolution and potatoes are not an exception. It is proposed that the proliferation of Long Terminal Repeat-retrotransposons (LTR-RT) is related to genome reorganization caused by hybridization and/or polyploidization. The main purpose of the present work was to evaluate the effect of interspecific hybridization and polyploidization on the activation of LTR-RT. We evaluated the proliferation of putative active LTR-RT in a diploid hybrid between the cultivated potato Solanum tuberosum and the wild diploid potato species S. kurtzianum, allotetraploid lines derived from this interspecific hybrid and S. kurtzianum autotetraploid lines (ktz-autotetraploid) using the S-SAP (sequence-specific amplified polymorphism) technique and normalized copy number determination by qPCR. Twenty-nine LTR-RT copies were activated in the hybrid and present in the allotetraploid lines. Major LTR-RT activity was detected in Copia-27, Copia-12, Copia-14 and, Gypsy-22. According to our results, LTR-RT copies were activated principally in the hybrid, there was no activation in allotetraploid lines and only one copy was activated in the autotetraploid.
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Affiliation(s)
- Magdalena Gantuz
- Facultad de Ciencias Agrarias, Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas (IBAM-CONICET), Universidad Nacional de Cuyo, A. Brown 500 (M5528AHB) Chacras de Coria, Mendoza, Argentina.
| | - Andrés Morales
- Instituto Nacional de Tecnología Agropecuaria (INTA), Luján de Cuyo, Mendoza, Argentina
| | - María Victoria Bertoldi
- Facultad de Ciencias Agrarias, Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas (IBAM-CONICET), Universidad Nacional de Cuyo, A. Brown 500 (M5528AHB) Chacras de Coria, Mendoza, Argentina
| | - Verónica Noé Ibañez
- Facultad de Ciencias Agrarias, Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas (IBAM-CONICET), Universidad Nacional de Cuyo, A. Brown 500 (M5528AHB) Chacras de Coria, Mendoza, Argentina
| | - Paola Fernanda Duarte
- Facultad de Ciencias Agrarias, Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas (IBAM-CONICET), Universidad Nacional de Cuyo, A. Brown 500 (M5528AHB) Chacras de Coria, Mendoza, Argentina
| | - Carlos Federico Marfil
- Facultad de Ciencias Agrarias, Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas (IBAM-CONICET), Universidad Nacional de Cuyo, A. Brown 500 (M5528AHB) Chacras de Coria, Mendoza, Argentina
| | - Ricardo Williams Masuelli
- Facultad de Ciencias Agrarias, Instituto de Biología Agrícola de Mendoza, Consejo Nacional de Investigaciones Científicas y Técnicas (IBAM-CONICET), Universidad Nacional de Cuyo, A. Brown 500 (M5528AHB) Chacras de Coria, Mendoza, Argentina.
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7
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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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8
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Yañez-Santos AM, Paz RC, Paz-Sepúlveda PB, Urdampilleta JD. Full-length LTR retroelements in Capsicum annuum revealed a few species-specific family bursts with insertional preferences. Chromosome Res 2021; 29:261-284. [PMID: 34086192 DOI: 10.1007/s10577-021-09663-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 05/04/2021] [Accepted: 05/06/2021] [Indexed: 01/01/2023]
Abstract
Capsicum annuum is a species that has undergone an expansion of the size of its genome caused mainly by the amplification of repetitive DNA sequences, including mobile genetic elements. Based on information obtained from sequencing the genome of pepper, the estimated fraction of retroelements is approximately 81%, and previous results revealed an important contribution of lineages derived from Gypsy superfamily. However, the dynamics of the retroelements in the C. annuum genome is poorly understood. In this way, the present work seeks to investigate the phylogenetic diversity and genomic abundance of the families of autonomous (complete and intact) LTR retroelements from C. annuum and inspect their distribution along its chromosomes. In total, we identified 1151 structurally full-length retroelements (340 Copia; 811 Gypsy) grouped in 124 phylogenetic families in the base of their retrotranscriptase. All the evolutive lineages of LTR retroelements identified in plants were present in pepper; however, three of them comprise 83% of the entire LTR retroelements population, the lineages Athila, Del/Tekay, and Ale/Retrofit. From them, only three families represent 70.8% of the total number of the identified retroelements. A massive family-specific wave of amplification of two of them occurred in the last 0.5 Mya (GypsyCa_16; CopiaCa_01), whereas the third is more ancient and occurred 3.0 Mya (GypsyCa_13). Fluorescent in situ hybridization performed with family and lineage-specific probes revealed contrasting patterns of chromosomal affinity. Our results provide a database of the populations LTR retroelements specific to C. annuum genome. The most abundant families were analyzed according to chromosome insertional preferences, suppling useful tools to the design of retroelement-based markers specific to the species.
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Affiliation(s)
- Anahí Mara Yañez-Santos
- CIGEOBIO (FCEFyN, UNSJ/CONICET), Av. Ignacio de la Roza 590 (Oeste), J5402DCS, Rivadavia, San Juan, Argentina.,Instituto Multidisciplinario de Biología Vegetal (IMBIV), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
| | - Rosalía Cristina Paz
- CIGEOBIO (FCEFyN, UNSJ/CONICET), Av. Ignacio de la Roza 590 (Oeste), J5402DCS, Rivadavia, San Juan, Argentina.
| | - Paula Beatriz Paz-Sepúlveda
- Instituto Multidisciplinario de Biología Celular (IMBICE), Consejo Nacional de Investigaciones Científicas y Técnicas de la República Argentina (CONICET) - Comisión de Investigaciones Científicas (CIC) - Universidad Nacional de La Plata (UNLP), La Plata, Argentina
| | - Juan Domingo Urdampilleta
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
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9
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Borredá C, Pérez-Román E, Ibanez V, Terol J, Talon M. Reprogramming of Retrotransposon Activity during Speciation of the Genus Citrus. Genome Biol Evol 2020; 11:3478-3495. [PMID: 31710678 PMCID: PMC7145672 DOI: 10.1093/gbe/evz246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2019] [Indexed: 12/13/2022] Open
Abstract
Speciation of the genus Citrus from a common ancestor has recently been established to begin ∼8 Ma during the late Miocene, a period of major climatic alterations. Here, we report the changes in activity of Citrus LTR retrotransposons during the process of diversification that gave rise to the current Citrus species. To reach this goal, we analyzed four pure species that diverged early during Citrus speciation, three recent admixtures derived from those species and an outgroup of the Citrus clade. More than 30,000 retrotransposons were grouped in ten linages. Estimations of LTR insertion times revealed that retrotransposon activity followed a species-specific pattern of change that could be ascribed to one of three different models. In some genomes, the expected pattern of gradual transposon accumulation was suddenly arrested during the radiation of the ancestor that gave birth to the current Citrus species. The individualized analyses of retrotransposon lineages showed that in each and every species studied, not all lineages follow the general pattern of the species itself. For instance, in most of the genomes, the retrotransposon activity of elements from the SIRE lineage reached its highest level just before Citrus speciation, while for Retrofit elements, it has been steadily growing. Based on these observations, we propose that Citrus retrotransposons may respond to stressful conditions driving speciation as a part of the genetic response involved in adaptation. This proposal implies that the evolving conditions of each species interact with the internal regulatory mechanisms of the genome controlling the proliferation of mobile elements.
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Affiliation(s)
- Carles Borredá
- Centro de Genómica, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain
| | - Estela Pérez-Román
- Centro de Genómica, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain
| | - Victoria Ibanez
- Centro de Genómica, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain
| | - Javier Terol
- Centro de Genómica, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain
| | - Manuel Talon
- Centro de Genómica, Instituto Valenciano de Investigaciones Agrarias (IVIA), Valencia, Spain
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Usai G, Mascagni F, Vangelisti A, Giordani T, Ceccarelli M, Cavallini A, Natali L. Interspecific hybridisation and LTR-retrotransposon mobilisation-related structural variation in plants: A case study. Genomics 2019; 112:1611-1621. [PMID: 31605729 DOI: 10.1016/j.ygeno.2019.09.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 07/13/2019] [Accepted: 09/12/2019] [Indexed: 11/30/2022]
Abstract
The dynamics of long-terminal-repeat retrotransposons in two poplar species (Populus deltoides and P. nigra) and in an interspecific hybrid, recently synthesized, were investigated by analyzing the genomic abundance and transcription levels of a collection of 828 full-length retroelements identified in the genome sequence of P. trichocarpa, all occurring also in the genomes of P. deltoides and P. nigra. Overall, genomic abundance and transcription levels of many retrotransposons in the hybrid resulted higher or lower than expected by calculating the mean of the parental values. A bioinformatics procedure was established to ascertain the occurrence of the same retrotransposon loci in the three genotypes. The results indicated that retrotransposon abundance variations between the hybrid and the mean value of the parents were due to i) co-segregation of retrotransposon high- or low-abundant haplotypes; ii) new retroelement insertions; iii) retrotransposon loss. Concerning retrotransposon expression, this was generally low, with only 14/828 elements over- or under-expressed in the hybrid than expected by calculating the mean of the parents. It is concluded that interspecific hybridisation between the two poplar species determine quantitative variation and differential expression of some retrotransposons, with possible consequences for the genetic differentiation of the hybrid.
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Affiliation(s)
- Gabriele Usai
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy
| | - Flavia Mascagni
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy
| | - Alberto Vangelisti
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy
| | - Tommaso Giordani
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy
| | - Marilena Ceccarelli
- Department of Chemistry, Biology and Biotechnology, University of Perugia, Via Elce di sotto 8, 06123 Perugia, Italy
| | - Andrea Cavallini
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy.
| | - Lucia Natali
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, I-56124 Pisa, Italy.
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11
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Li SF, Guo YJ, Li JR, Zhang DX, Wang BX, Li N, Deng CL, Gao WJ. The landscape of transposable elements and satellite DNAs in the genome of a dioecious plant spinach ( Spinacia oleracea L.). Mob DNA 2019; 10:3. [PMID: 30675191 PMCID: PMC6337768 DOI: 10.1186/s13100-019-0147-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Accepted: 01/07/2019] [Indexed: 11/10/2022] Open
Abstract
Background Repetitive sequences, including transposable elements (TEs) and satellite DNAs, occupy a considerable portion of plant genomes. Analysis of the repeat fraction benefits the understanding of genome structure and evolution. Spinach (Spinacia oleracea L.), an important vegetable crop, is also a model dioecious plant species for studying sex determination and sex chromosome evolution. However, the repetitive sequences of the spinach genome have not been fully investigated. Results We extensively analyzed the repetitive components of draft spinach genome, especially TEs and satellites, by different strategies. A total of 16,002 full-length TEs were identified. Among the most abundant long terminal repeat (LTR) retrotransposons (REs), Copia elements were overrepresented compared with Gypsy ones. Angela was the most dominating Copia lineage; Ogre/Tat was the most abundant Gypsy lineage. The mean insertion age of LTR-REs was 1.42 million years; approximately 83.7% of these elements were retrotransposed during the last two million years. RepeatMasker totally masked about 64.05% of the spinach genome, with LTR-REs, non-LTR-REs, and DNA transposons occupying 49.2, 2.4, and 5.6%, respectively. Fluorescence in situ hybridization (FISH) analysis showed that most LTR-REs dispersed all over the chromosomes, by contrast, elements of CRM lineage were distributed at the centromeric region of all chromosomes. In addition, Ogre/Tat lineage mainly accumulated on sex chromosomes, and satellites Spsat2 and Spsat3 were exclusively located at the telomeric region of the short arm of sex chromosomes. Conclusions We reliably annotated the TE fraction of the draft genome of spinach. FISH analysis indicates that Ogre/Tat lineage and the sex chromosome-specific satellites DNAs might participate in sex chromosome formation and evolution. Based on FISH signals of microsatellites, together with 45S rDNA, a fine karyotype of spinach was established. This study improves our knowledge of repetitive sequence organization in spinach genome and aids in accurate spinach karyotype construction. Electronic supplementary material The online version of this article (10.1186/s13100-019-0147-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Shu-Fen Li
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
| | - Yu-Jiao Guo
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
| | - Jia-Rong Li
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
| | - Dong-Xu Zhang
- 2College of Life Science, Shanxi Datong University, Datong, 037009 China
| | - Bing-Xiao Wang
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
| | - Ning Li
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
| | - Chuan-Liang Deng
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
| | - Wu-Jun Gao
- 1College of Life Sciences, Henan Normal University, Xinxiang, 453007 China
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Paz RC, Kozaczek ME, Rosli HG, Andino NP, Sanchez-Puerta MV. Diversity, distribution and dynamics of full-length Copia and Gypsy LTR retroelements in Solanum lycopersicum. Genetica 2017; 145:417-430. [PMID: 28776161 DOI: 10.1007/s10709-017-9977-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/26/2017] [Indexed: 12/18/2022]
Abstract
Transposable elements are the most abundant components of plant genomes and can dramatically induce genetic changes and impact genome evolution. In the recently sequenced genome of tomato (Solanum lycopersicum), the estimated fraction of elements corresponding to retrotransposons is nearly 62%. Given that tomato is one of the most important vegetable crop cultivated and consumed worldwide, understanding retrotransposon dynamics can provide insight into its evolution and domestication processes. In this study, we performed a genome-wide in silico search of full-length LTR retroelements in the tomato nuclear genome and annotated 736 full-length Gypsy and Copia retroelements. The dispersion level across the 12 chromosomes, the diversity and tissue-specific expression of those elements were estimated. Phylogenetic analysis based on the retrotranscriptase region revealed the presence of 12 major lineages of LTR retroelements in the tomato genome. We identified 97 families, of which 77 and 20 belong to the superfamilies Copia and Gypsy, respectively. Each retroelement family was characterized according to their element size, relative frequencies and insertion time. These analyses represent a valuable resource for comparative genomics within the Solanaceae, transposon-tagging and for the design of cultivar-specific molecular markers in tomato.
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Affiliation(s)
- Rosalía Cristina Paz
- CIGEOBIO (FCEFyN, UNSJ/CONICET), Av. Ignacio de la Roza 590 (Oeste), J5402DCS, Rivadavia, San Juan, Argentina.
| | - Melisa Eliana Kozaczek
- Facultad de Ciencias Exactas, Químicas y Naturales, Universidad Nacional de Misiones, Posadas, Misiones, Argentina
| | - Hernán Guillermo Rosli
- Instituto de Fisiología Vegetal, INFIVE, Universidad Nacional de La Plata, CONICET, La Plata, Buenos Aires, Argentina
| | - Natalia Pilar Andino
- Facultad de Ciencias Exactas, Físicas y Naturales, Universidad Nacional de San Juan, San Juan, Argentina
| | - Maria Virginia Sanchez-Puerta
- IBAM, Universidad Nacional de Cuyo, CONICET, FCA and FCEN, Almirante Brown 500, M5528AHB, Chacras de Coria, Argentina
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Abstract
LTR retrotransposons are the most abundant group of transposable elements (TEs) in plants. These elements can fall inside or close to genes, and therefore influence their expression and evolution. This review aims to examine how LTR retrotransposons, especially Ty1-copia elements, mediate gene regulation and evolution. Various stimuli, including polyploidization and biotic and abiotic elicitors, result in the transcription and movement of these retrotransposons, and can facilitate adaptation. The presence of cis-regulatory motifs in the LTRs are central to their stress-mediated responses and are shared with host stress-responsive genes, showing a complex evolutionary history in which TEs provide new regulatory units to genes. The presence of retrotransposon remnants in genes that are necessary for normal gene function, demonstrates the importance of exaptation and co-option, and is also a consequence of the abundance of these elements in plant genomes. Furthermore, insertions of LTR retrotransposons in and around genes provide potential for alternative splicing, epigenetic control, transduction, duplication and recombination. These characteristics can become an active part of the evolution of gene families as in the case of resistance genes (R-genes). The character of TEs as exclusively selfish is now being re-evaluated. Since genome-wide reprogramming via TEs is a long evolutionary process, the changes we can examine are case-specific and their fitness advantage may not be evident until TE-derived motifs and domains have been completely co-opted and fixed. Nevertheless, the presence of LTR retrotransposons inside genes and as part of gene promoter regions is consistent with their roles as engines of plant genome evolution.
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Gimenez MD, Yañez-Santos AM, Paz RC, Quiroga MP, Marfil CF, Conci VC, García-Lampasona SC. Assessment of genetic and epigenetic changes in virus-free garlic (Allium sativum L.) plants obtained by meristem culture followed by in vitro propagation. PLANT CELL REPORTS 2016; 35:129-41. [PMID: 26466594 DOI: 10.1007/s00299-015-1874-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 08/14/2015] [Accepted: 09/25/2015] [Indexed: 05/05/2023]
Abstract
This is the first report assessing epigenetic variation in garlic. High genetic and epigenetic polymorphism during in vitro culture was detected.Sequencing of MSAP fragments revealed homology with ESTs. Garlic (Allium sativum) is a worldwide crop of economic importance susceptible to viral infections that can cause significant yield losses. Meristem tissue culture is the most employed method to sanitize elite cultivars.Often the virus-free garlic plants obtained are multiplied in vitro (micro propagation). However, it was reported that micro-propagation frequently produces somaclonal variation at the phenotypic level, which is an undesirable trait when breeders are seeking to maintain varietal stability. We employed amplification fragment length polymorphism and methylation sensitive amplified polymorphism (MSAP) methodologies to assess genetic and epigenetic modifications in two culture systems: virus-free plants obtained by meristem culture followed by in vitro multiplication and field culture. Our results suggest that garlic exhibits genetic and epigenetic polymorphism under field growing conditions. However, during in vitro culture system both kinds of polymorphisms intensify indicating that this system induces somaclonal variation. Furthermore, while genetic changes accumulated along the time of in vitro culture, epigenetic polymorphism reached the major variation at 6 months and then stabilize, being demethylation and CG methylation the principal conversions.Cloning and sequencing differentially methylated MSAP fragments allowed us to identify coding and unknown sequences of A. sativum, including sequences belonging to LTR Gypsy retrotransposons. Together, our results highlight that main changes occur in the initial 6 months of micro propagation. For the best of our knowledge, this is the first report on epigenetic assessment in garlic.
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