1
|
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.
Collapse
Affiliation(s)
| | - Carlos M. Vicient
- Centre for Research in Agricultural Genomics, CRAG (CSIC-IRTA-UAB-UB), Campus UAB, Cerdanyola del Vallès, 08193 Barcelona, Spain
| |
Collapse
|
2
|
Duan T, Sicard A, Glémin S, Lascoux M. Expression pattern of resynthesized allotetraploid Capsella is determined by hybridization, not whole-genome duplication. THE NEW PHYTOLOGIST 2023; 237:339-353. [PMID: 36254103 PMCID: PMC10099941 DOI: 10.1111/nph.18542] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Polyploidization, the process leading to the increase in chromosome sets, is a major evolutionary transition in plants. Whole-genome duplication (WGD) within the same species gives rise to autopolyploids, whereas allopolyploids result from a compound process with two distinct components: WGD and interspecific hybridization. To dissect the instant effects of WGD and hybridization on gene expression and phenotype, we created a series of synthetic hybrid and polyploid Capsella plants, including diploid hybrids, autotetraploids of both parental species, and two kinds of resynthesized allotetraploids with different orders of WGD and hybridization. Hybridization played a major role in shaping the relative expression pattern of the neo-allopolyploids, whereas WGD had almost no immediate effect on relative gene expression pattern but, nonetheless, still affected phenotypes. No transposable element-mediated genomic shock scenario was observed in either neo-hybrids or neo-polyploids. Finally, WGD and hybridization interacted and the distorting effects of WGD were less strong in hybrids. Whole-genome duplication may even improve hybrid fertility. In summary, while the initial relative gene expression pattern in neo-allotetraploids was almost entirely determined by hybridization, WGD only had trivial effects on relative expression patterns, both processes interacted and had a strong impact on physical attributes and meiotic behaviors.
Collapse
Affiliation(s)
- Tianlin Duan
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life LaboratoryUppsala University75236UppsalaSweden
| | - Adrien Sicard
- Department of Plant BiologySwedish University of Agricultural Sciences750 07UppsalaSweden
| | - Sylvain Glémin
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life LaboratoryUppsala University75236UppsalaSweden
- UMR CNRS 6553 ECOBIOCampus Beaulieu, bât 14a, p.118, CS 7420535042RennesFrance
| | - Martin Lascoux
- Department of Ecology and Genetics, Evolutionary Biology Centre and Science for Life LaboratoryUppsala University75236UppsalaSweden
| |
Collapse
|
3
|
Martin SL, Lujan Toro B, James T, Sauder CA, Laforest M. Insights from the genomes of 4 diploid Camelina spp. G3 (BETHESDA, MD.) 2022; 12:jkac182. [PMID: 35976116 PMCID: PMC9713399 DOI: 10.1093/g3journal/jkac182] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 06/12/2022] [Indexed: 11/12/2022]
Abstract
Plant evolution has been a complex process involving hybridization and polyploidization making understanding the origin and evolution of a plant's genome challenging even once a published genome is available. The oilseed crop, Camelina sativa (Brassicaceae), has a fully sequenced allohexaploid genome with 3 unknown ancestors. To better understand which extant species best represent the ancestral genomes that contributed to C. sativa's formation, we sequenced and assembled chromosome level draft genomes for 4 diploid members of Camelina: C. neglecta C. hispida var. hispida, C. hispida var. grandiflora, and C. laxa using long and short read data scaffolded with proximity data. We then conducted phylogenetic analyses on regions of synteny and on genes described for Arabidopsis thaliana, from across each nuclear genome and the chloroplasts to examine evolutionary relationships within Camelina and Camelineae. We conclude that C. neglecta is closely related to C. sativa's sub-genome 1 and that C. hispida var. hispida and C. hispida var. grandiflora are most closely related to C. sativa's sub-genome 3. Further, the abundance and density of transposable elements, specifically Helitrons, suggest that the progenitor genome that contributed C. sativa's sub-genome 3 maybe more similar to the genome of C. hispida var. hispida than that of C. hispida var. grandiflora. These diploid genomes show few structural differences when compared to C. sativa's genome indicating little change to chromosome structure following allopolyploidization. This work also indicates that C. neglecta and C. hispida are important resources for understanding the genetics of C. sativa and potential resources for crop improvement.
Collapse
Affiliation(s)
- Sara L Martin
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0CA, Canada
| | - Beatriz Lujan Toro
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0CA, Canada
| | - Tracey James
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0CA, Canada
| | - Connie A Sauder
- Ottawa Research and Development Centre, Agriculture and Agri-Food Canada, Ottawa, ON K1A 0CA, Canada
| | - Martin Laforest
- Saint-Jean-sur-Richelieu Research and Development Centre, Agriculture and Agri-Food Canada, Saint-Jean-sur-Richelieu, QC J3B 3E6, Canada
| |
Collapse
|
4
|
Scarlett VT, Lovell JT, Shao M, Phillips J, Shu S, Lusinska J, Goodstein DM, Jenkins J, Grimwood J, Barry K, Chalhoub B, Schmutz J, Hasterok R, Catalán P, Vogel JP. Multiple origins, one evolutionary trajectory: gradual evolution characterizes distinct lineages of allotetraploid Brachypodium. Genetics 2022; 223:6758249. [PMID: 36218464 PMCID: PMC9910409 DOI: 10.1093/genetics/iyac146] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 09/16/2022] [Indexed: 11/13/2022] Open
Abstract
The "genomic shock" hypothesis posits that unusual challenges to genome integrity such as whole genome duplication may induce chaotic genome restructuring. Decades of research on polyploid genomes have revealed that this is often, but not always the case. While some polyploids show major chromosomal rearrangements and derepression of transposable elements in the immediate aftermath of whole genome duplication, others do not. Nonetheless, all polyploids show gradual diploidization over evolutionary time. To evaluate these hypotheses, we produced a chromosome-scale reference genome for the natural allotetraploid grass Brachypodium hybridum, accession "Bhyb26." We compared 2 independently derived accessions of B. hybridum and their deeply diverged diploid progenitor species Brachypodium stacei and Brachypodium distachyon. The 2 B. hybridum lineages provide a natural timecourse in genome evolution because one formed 1.4 million years ago, and the other formed 140 thousand years ago. The genome of the older lineage reveals signs of gradual post-whole genome duplication genome evolution including minor gene loss and genome rearrangement that are missing from the younger lineage. In neither B. hybridum lineage do we find signs of homeologous recombination or pronounced transposable element activation, though we find evidence supporting steady post-whole genome duplication transposable element activity in the older lineage. Gene loss in the older lineage was slightly biased toward 1 subgenome, but genome dominance was not observed at the transcriptomic level. We propose that relaxed selection, rather than an abrupt genomic shock, drives evolutionary novelty in B. hybridum, and that the progenitor species' similarity in transposable element load may account for the subtlety of the observed genome dominance.
Collapse
Affiliation(s)
- Virginia T Scarlett
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA,Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - John T Lovell
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Mingqin Shao
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Jeremy Phillips
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Shengqiang Shu
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | | | - David M Goodstein
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Jerry Jenkins
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Jane Grimwood
- Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Kerrie Barry
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | | | - Jeremy Schmutz
- U.S. Dept. of Energy Joint Genome Institute, Berkeley, CA 94720, USA,Genome Sequencing Center, HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | | | | | - John P Vogel
- Corresponding author: U.S. Dept. of Energy Joint Genome Institute, 1 Cyclotron Road, Berkeley, CA 94720, USA.
| |
Collapse
|
5
|
Eriksson MC, Mandáková T, McCann J, Temsch EM, Chase MW, Hedrén M, Weiss-Schneeweiss H, Paun O. Repeat dynamics across timescales: a perspective from sibling allotetraploid marsh orchids (Dactylorhiza majalis s.l.). Mol Biol Evol 2022; 39:6651906. [PMID: 35904928 PMCID: PMC9366187 DOI: 10.1093/molbev/msac167] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
To provide insights into the fate of transposable elements (TEs) across timescales in a post-polyploidization context, we comparatively investigate five sibling Dactylorhiza allotetraploids (Orchidaceae) formed independently and sequentially between 500 and 100K generations ago by unidirectional hybridization between diploids D. fuchsii and D. incarnata. Our results first reveal that the paternal D. incarnata genome shows a marked increased content of LTR retrotransposons compared to the maternal species, reflected in its larger genome size and consistent with a previously hypothesized bottleneck. With regard to the allopolyploids, in the youngest D. purpurella both genome size and TE composition appear to be largely additive with respect to parents, whereas for polyploids of intermediate ages we uncover rampant genome expansion on a magnitude of multiple entire genomes of some plants such as Arabidopsis. The oldest allopolyploids in the series are not larger than the intermediate ones. A putative tandem repeat, potentially derived from a non-autonomous miniature inverted-repeat TE (MITE) drives much of the genome dynamics in the allopolyploids. The highly dynamic MITE-like element is found in higher proportions in the maternal diploid, D. fuchsii, but is observed to increase in copy number in both subgenomes of the allopolyploids. Altogether, the fate of repeats appears strongly regulated and therefore predictable across multiple independent allopolyploidization events in this system. Apart from the MITE-like element, we consistently document a mild genomic shock following the allopolyploidizations investigated here, which may be linked to their relatively large genome sizes, possibly associated with strong selection against further genome expansions.
Collapse
Affiliation(s)
- Mimmi C Eriksson
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria.,Vienna Graduate School of Population Genetics, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Terezie Mandáková
- Plant Cytogenomics Research Group, CEITEC-Central - European Institute of Technology, Masaryk University, Brno 62500, Czech Republic
| | - Jamie McCann
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
| | - Eva M Temsch
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
| | - Mark W Chase
- Royal Botanic Gardens Kew, London TW9 3AE, United Kingdom.,Department of Environment and Agriculture, Curtin University, Perth, Western Australia, Australia
| | - Mikael Hedrén
- Department of Biology, University of Lund, Sölvegatan 37, SE-223 62 Lund, Sweden
| | - Hanna Weiss-Schneeweiss
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
| | - Ovidiu Paun
- Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, A-1030 Vienna, Austria
| |
Collapse
|
6
|
Catlin NS, Josephs EB. The important contribution of transposable elements to phenotypic variation and evolution. CURRENT OPINION IN PLANT BIOLOGY 2022; 65:102140. [PMID: 34883307 DOI: 10.1016/j.pbi.2021.102140] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/04/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
Transposable elements (TEs) are responsible for significant genomic variation in plants. Our understanding of the evolutionary forces shaping TE polymorphism has lagged behind other mutations because of the difficulty of accurately identifying TE polymorphism in short-read population genomic data. However, new approaches allow us to quantify TE polymorphisms in population datasets and address fundamental questions about the evolution of these polymorphisms. Here, we discuss how insertional biases shape where, when, and how often TEs insert throughout the genome. Next, we examine mechanisms by which TEs can affect phenotype. Finally, we evaluate current evidence for selection on TE polymorphisms. All together, it is clear that TEs are important, but underappreciated, contributors to intraspecific phenotypic variation, and that understanding the dynamics governing TE polymorphism is crucial for evolutionary biologists interested in the maintenance of variation.
Collapse
Affiliation(s)
- Nathan S Catlin
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA; Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI, 48824, USA.
| | - Emily B Josephs
- Department of Plant Biology, Michigan State University, East Lansing, MI, 48824, USA; Ecology, Evolution, and Behavior Program, Michigan State University, East Lansing, MI, 48824, USA
| |
Collapse
|
7
|
Beric A, Mabry ME, Harkess AE, Brose J, Schranz ME, Conant GC, Edger PP, Meyers BC, Pires JC. Comparative phylogenetics of repetitive elements in a diverse order of flowering plants (Brassicales). G3 (BETHESDA, MD.) 2021; 11:jkab140. [PMID: 33993297 PMCID: PMC8495927 DOI: 10.1093/g3journal/jkab140] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 04/10/2021] [Indexed: 11/14/2022]
Abstract
Genome sizes of plants have long piqued the interest of researchers due to the vast differences among organisms. However, the mechanisms that drive size differences have yet to be fully understood. Two important contributing factors to genome size are expansions of repetitive elements, such as transposable elements (TEs), and whole-genome duplications (WGD). Although studies have found correlations between genome size and both TE abundance and polyploidy, these studies typically test for these patterns within a genus or species. The plant order Brassicales provides an excellent system to further test if genome size evolution patterns are consistent across larger time scales, as there are numerous WGDs. This order is also home to one of the smallest plant genomes, Arabidopsis thaliana-chosen as the model plant system for this reason-as well as to species with very large genomes. With new methods that allow for TE characterization from low-coverage genome shotgun data and 71 taxa across the Brassicales, we confirm the correlation between genome size and TE content, however, we are unable to reconstruct phylogenetic relationships and do not detect any shift in TE abundance associated with WGD.
Collapse
Affiliation(s)
- Aleksandra Beric
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - Makenzie E Mabry
- Division of Biological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| | - Alex E Harkess
- Department of Crop, Soil, and Environmental Sciences, Auburn University, Auburn, AL 36849, USA
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806, USA
| | - Julia Brose
- Department of Plant Biology, Michigan State University, East Lansing, MI 48824, USA
| | - M Eric Schranz
- Biosystematics Group, Wageningen University, Wageningen 6700 AA, The Netherlands
| | - Gavin C Conant
- Bioinformatics Research Center, Program in Genetics and Department of Biological Sciences, North Carolina State University, Raleigh, NC 27695, USA
| | - Patrick P Edger
- Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA
- Department of Ecology, Evolutionary Biology and Behavior, Michigan State University, East Lansing, MI 48824, USA
| | - Blake C Meyers
- Donald Danforth Plant Science Center, St. Louis, MO 63132, USA
- Division of Plant Sciences, University of Missouri, Columbia, MO 65211, USA
| | - J Chris Pires
- Division of Biological Sciences and Bond Life Sciences Center, University of Missouri, Columbia, MO 65211, USA
| |
Collapse
|
8
|
Bishani A, Prokopov DY, Romanenko SA, Molodtseva AS, Perelman PL, Interesova EA, Beklemisheva VR, Graphodatsky AS, Trifonov VA. Evolution of Tandemly Arranged Repetitive DNAs in Three Species of Cyprinoidei with Different Ploidy Levels. Cytogenet Genome Res 2021; 161:32-42. [PMID: 33677437 DOI: 10.1159/000513274] [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: 04/15/2020] [Accepted: 08/10/2020] [Indexed: 11/19/2022] Open
Abstract
Polyploid species represent a challenge for both cytogenetic and genomic studies due to their high chromosome numbers and the morphological similarity between their paralogous chromosomes. This paper describes the use of low-coverage high-throughput sequencing to identify the 14 most abundant tandemly arranged repetitive elements in the paleotetraploid genome of the crucian carp (Carassius carassius, 2n = 100). These repetitive elements were then used for molecular cytogenetic studies of a closely related functionally triploid form of the Prussian carp (Carassius gibelio, 3n = 150 + Bs) and a relatively distant diploid species, the tench (Tinca tinca, 2n = 48). According to their distribution on the chromosomes of the 3 aforementioned species, the repetitive elements here identified can be divided into 5 groups: (1) those specific to a single genomic locus in both Carassius species, despite the recent carp-specific genome duplication; (2) those located in a single genomic locus of T. tinca, but amplified in one or both Carassius species; (3) those massively amplified in the B chromosomes of C. gibelio; (4) those located in a single locus in C. gibelio, but amplified in many blocks in C. carassius; and (5) those located in multiple pericentromeric loci in both Carassius species. Our data indicate that some of the repetitive elements are highly conserved in cyprinoid species and may serve as good cytogenetic and genomic markers for discriminating paralogous chromosomes, while others are evolutionarily recent, and their amplification may be related to the last whole-genome duplication event.
Collapse
Affiliation(s)
- Ali Bishani
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russian Federation, .,Novosibirsk State University, Novosibirsk, Russian Federation,
| | - Dmitry Y Prokopov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russian Federation
| | - Svetlana A Romanenko
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russian Federation
| | - Anna S Molodtseva
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russian Federation
| | - Polina L Perelman
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russian Federation
| | - Elena A Interesova
- Department of Ichthyology and Hydrobiology, Tomsk State University, Tomsk, Russian Federation
| | | | | | - Vladimir A Trifonov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russian Federation.,Novosibirsk State University, Novosibirsk, Russian Federation
| |
Collapse
|
9
|
Evolutionary Dynamics of Transposable Elements Following a Shared Polyploidization Event in the Tribe Andropogoneae. G3-GENES GENOMES GENETICS 2020; 10:4387-4398. [PMID: 32988994 PMCID: PMC7718754 DOI: 10.1534/g3.120.401596] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Both polyploidization and transposable element (TE) activity are known to be major drivers of plant genome evolution. Here, we utilize the Zea-Tripsacum clade to investigate TE activity and accumulation after a shared polyploidization event. Comparisons of TE evolutionary dynamics in various Zea and Tripsacum species, in addition to two closely related diploid species, Urelytrum digitatum and Sorghum bicolor, revealed variation in repeat content among all taxa included in the study. The repeat composition of Urelytrum is more similar to that of Zea and Tripsacum compared to Sorghum, despite the similarity in genome size with the latter. Although LTR-retrotransposons were abundant in all species, we observed an expansion of the copia superfamily, specifically in Z. mays and T. dactyloides, species that have adapted to more temperate environments. Additional analyses of the genomic distribution of these retroelements provided evidence of biased insertions near genes involved in various biological processes including plant development, defense, and macromolecule biosynthesis. Specifically, copia insertions in Zea and T. dactyloides were significantly enriched near genes involved in abiotic stress response, suggesting independent evolution post Zea-Tripsacum divergence. The lack of copia insertions near the orthologous genes in S. bicolor suggests that duplicate gene copies generated during polyploidization may offer novel neutral sites for TEs to insert, thereby providing an avenue for subfunctionalization via TE insertional mutagenesis.
Collapse
|
10
|
Abstract
Tomatoes come in a multitude of shapes and flavors despite a narrow genetic pool. Here, we leverage whole-genome resequencing data available for 602 cultivated and wild accessions to determine the contribution of transposable elements (TEs) to tomato diversity. We identify 6,906 TE insertions polymorphisms (TIPs), which result from the mobilization of 337 distinct TE families. Most TIPs are low frequency variants and TIPs are disproportionately located within or adjacent to genes involved in environmental responses. In addition, genic TE insertions tend to have strong transcriptional effects and they can notably lead to the generation of multiple transcript isoforms. Using genome-wide association studies (GWAS), we identify at least 40 TIPs robustly associated with extreme variation in major agronomic traits or secondary metabolites and in most cases, no SNP tags the TE insertion allele. Collectively, these findings highlight the unique role of TE mobilization in tomato diversification, with important implications for breeding. Transposable element insertion polymorphisms (TIPs) are a potential source of large effect alleles. Here, the authors use genome resequencing data for 602 tomato accessions together with transcriptomic and extensive phenotypic information to investigate the contribution of TIPs to tomato diversity.
Collapse
|
11
|
Nieto Feliner G, Casacuberta J, Wendel JF. Genomics of Evolutionary Novelty in Hybrids and Polyploids. Front Genet 2020; 11:792. [PMID: 32849797 PMCID: PMC7399645 DOI: 10.3389/fgene.2020.00792] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/03/2020] [Indexed: 12/15/2022] Open
Abstract
It has long been recognized that hybridization and polyploidy are prominent processes in plant evolution. Although classically recognized as significant in speciation and adaptation, recognition of the importance of interspecific gene flow has dramatically increased during the genomics era, concomitant with an unending flood of empirical examples, with or without genome doubling. Interspecific gene flow is thus increasingly thought to lead to evolutionary innovation and diversification, via adaptive introgression, homoploid hybrid speciation and allopolyploid speciation. Less well understood, however, are the suite of genetic and genomic mechanisms set in motion by the merger of differentiated genomes, and the temporal scale over which recombinational complexity mediated by gene flow might be expressed and exposed to natural selection. We focus on these issues here, considering the types of molecular genetic and genomic processes that might be set in motion by the saltational event of genome merger between two diverged species, either with or without genome doubling, and how these various processes can contribute to novel phenotypes. Genetic mechanisms include the infusion of new alleles and the genesis of novel structural variation including translocations and inversions, homoeologous exchanges, transposable element mobilization and novel insertional effects, presence-absence variation and copy number variation. Polyploidy generates massive transcriptomic and regulatory alteration, presumably set in motion by disrupted stoichiometries of regulatory factors, small RNAs and other genome interactions that cascade from single-gene expression change up through entire networks of transformed regulatory modules. We highlight both these novel combinatorial possibilities and the range of temporal scales over which such complexity might be generated, and thus exposed to natural selection and drift.
Collapse
Affiliation(s)
- Gonzalo Nieto Feliner
- Department of Biodiversity and Conservation, Real Jardín Botánico, CSIC, Madrid, Spain
| | - Josep Casacuberta
- Center for Research in Agricultural Genomics, CRAG (CSIC-IRTA-UAB-UB), Barcelona, Spain
| | - Jonathan F. Wendel
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, United States
| |
Collapse
|
12
|
Mattila TM, Laenen B, Slotte T. Population Genomics of Transitions to Selfing in Brassicaceae Model Systems. Methods Mol Biol 2020; 2090:269-287. [PMID: 31975171 DOI: 10.1007/978-1-0716-0199-0_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Many plants harbor complex mechanisms that promote outcrossing and efficient pollen transfer. These include floral adaptations as well as genetic mechanisms, such as molecular self-incompatibility (SI) systems. The maintenance of such systems over long evolutionary timescales suggests that outcrossing is favorable over a broad range of conditions. Conversely, SI has repeatedly been lost, often in association with transitions to self-fertilization (selfing). This transition is favored when the short-term advantages of selfing outweigh the costs, primarily inbreeding depression. The transition to selfing is expected to have major effects on population genetic variation and adaptive potential, as well as on genome evolution. In the Brassicaceae, many studies on the population genetic, gene regulatory, and genomic effects of selfing have centered on the model plant Arabidopsis thaliana and the crucifer genus Capsella. The accumulation of population genomics datasets have allowed detailed investigation of where, when and how the transition to selfing occurred. Future studies will take advantage of the development of population genetics theory on the impact of selfing, especially regarding positive selection. Furthermore, investigation of systems including recent transitions to selfing, mixed mating populations and/or multiple independent replicates of the same transition will facilitate dissecting the effects of mating system variation from processes driven by demography.
Collapse
Affiliation(s)
- Tiina M Mattila
- Department of Ecology and Genetics, University of Oulu, Oulu, Finland
| | - Benjamin Laenen
- Department of Ecology, Environment, and Plant Sciences, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Tanja Slotte
- Department of Ecology, Environment, and Plant Sciences, Science for Life Laboratory, Stockholm University, Stockholm, Sweden.
| |
Collapse
|
13
|
da Costa ZP, Cauz-Santos LA, Ragagnin GT, Van Sluys MA, Dornelas MC, Berges H, de Mello Varani A, Vieira MLC. Transposable element discovery and characterization of LTR-retrotransposon evolutionary lineages in the tropical fruit species Passiflora edulis. Mol Biol Rep 2019; 46:6117-6133. [DOI: 10.1007/s11033-019-05047-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 08/28/2019] [Indexed: 12/23/2022]
|
14
|
Hou J, Lu D, Mason AS, Li B, Xiao M, An S, Fu D. Non-coding RNAs and transposable elements in plant genomes: emergence, regulatory mechanisms and roles in plant development and stress responses. PLANTA 2019; 250:23-40. [PMID: 30993403 DOI: 10.1007/s00425-019-03166-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Accepted: 04/09/2019] [Indexed: 06/09/2023]
Abstract
This review will provide evidence for the indispensable function of these elements in regulating plant development and resistance to biotic and abiotic stresses, as well as their evolutionary role in facilitating plant adaptation. Over millions of years of evolution, plant genomes have acquired a complex constitution. Plant genomes consist not only of protein coding sequences, but also contain large proportions of non-coding sequences. These include introns of protein-coding genes, and intergenic sequences such as non-coding RNA, repeat sequences and transposable elements. These non-coding sequences help to regulate gene expression, and are increasingly being recognized as playing an important role in genome organization and function. In this review, we summarize the known molecular mechanisms by which gene expression is regulated by several species of non-coding RNAs (microRNAs, long non-coding RNAs, and circular RNAs) and by transposable elements. We further discuss how these non-coding RNAs and transposable elements evolve and emerge in the genome, and the potential influence and importance of these non-coding RNAs and transposable elements in plant development and in stress responses.
Collapse
Affiliation(s)
- Jinna Hou
- Crop Designing Centre, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China
| | - Dandan Lu
- Crop Designing Centre, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China
| | - Annaliese S Mason
- Plant Breeding Department, IFZ Research Centre for Biosystems, Land Use and Nutrition, Justus Liebig University, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany
| | - Baoquan Li
- Crop Designing Centre, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China
| | - Meili Xiao
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Agronomy College, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Sufang An
- Crop Designing Centre, Henan Academy of Agricultural Sciences, Zhengzhou, 450002, China
| | - Donghui Fu
- Key Laboratory of Crop Physiology, Ecology and Genetic Breeding, Ministry of Education, Agronomy College, Jiangxi Agricultural University, Nanchang, 330045, China.
| |
Collapse
|
15
|
Rivero R, Sessa EB, Zenil‐Ferguson R. EyeChrom and CCDBcurator: Visualizing chromosome count data from plants. APPLICATIONS IN PLANT SCIENCES 2019; 7:e01207. [PMID: 30693153 PMCID: PMC6342174 DOI: 10.1002/aps3.1207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/05/2018] [Indexed: 05/13/2023]
Abstract
PREMISE OF THE STUDY Chromosome count data are available for hundreds of plant species and can be explored in text-only format at the Chromosome Counts Database (http://ccdb.tau.ac.il). CCDBcurator and EyeChrom are an R package and a web application, respectively, that first curate and then visualize these data graphically, so that intra- and interspecific variation of chromosome numbers can be easily summarized and displayed for a given genus. METHODS AND RESULTS We developed R code to clean, summarize, and display in several formats the chromosome count data for a selected genus or set of species present in the Chromosome Counts Database. These data and figures can be exported for use in analyses, publications, or teaching. CONCLUSIONS Chromosome count data are critical for a number of evolutionary studies in plant biology, and their importance is underscored by the increasing appreciation of the prevalence of polyploidy in land plants. CCDBcurator and EyeChrom provide a fast, easy, and reproducible means of cleaning, curating, and then visualizing the chromosome count data currently available for plants.
Collapse
Affiliation(s)
- Rodrigo Rivero
- Department of BiologyUniversity of FloridaBox 118525GainesvilleFlorida32611USA
- Department of Natural Resources and Environmental ManagementUniversity of Hawaii1910 East‐West RoadManoaHawaii96822USA
| | - Emily B. Sessa
- Department of BiologyUniversity of FloridaBox 118525GainesvilleFlorida32611USA
| | - Rosana Zenil‐Ferguson
- Department of Ecology, Evolution, and BehaviorUniversity of Minnesota1479 Gortner AvenueSt. PaulMinnesota55108USA
| |
Collapse
|
16
|
Baduel P, Bray S, Vallejo-Marin M, Kolář F, Yant L. The “Polyploid Hop”: Shifting Challenges and Opportunities Over the Evolutionary Lifespan of Genome Duplications. Front Ecol Evol 2018. [DOI: 10.3389/fevo.2018.00117] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
17
|
Vicient CM, Casacuberta JM. Impact of transposable elements on polyploid plant genomes. ANNALS OF BOTANY 2017; 120:195-207. [PMID: 28854566 PMCID: PMC5737689 DOI: 10.1093/aob/mcx078] [Citation(s) in RCA: 143] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 05/23/2017] [Indexed: 05/18/2023]
Abstract
BACKGROUND The growing wealth of knowledge on whole-plant genome sequences is highlighting the key role of transposable elements (TEs) in plant evolution, as a driver of drastic changes in genome size and as a source of an important number of new coding and regulatory sequences. Together with polyploidization events, TEs should thus be considered the major players in evolution of plants. SCOPE This review outlines the major mechanisms by which TEs impact plant genome evolution and how polyploidy events can affect these impacts, and vice versa. These include direct effects on genes, by providing them with new coding or regulatory sequences, an effect on the epigenetic status of the chromatin close to genes, and more subtle effects by imposing diverse evolutionary constraints to different chromosomal regions. These effects are particularly relevant after polyploidization events. Polyploidization often induces bursts of transposition probably due to a relaxation in their epigenetic control, and, in the short term, this can increase the rate of gene mutations and changes in gene regulation due to the insertion of TEs next to or into genes. Over longer times, TE bursts may induce global changes in genome structure due to inter-element recombination including losses of large genome regions and chromosomal rearrangements that reduce the genome size and the chromosome number as part of a process called diploidization. CONCLUSIONS TEs play an essential role in genome and gene evolution, in particular after polyploidization events. Polyploidization can induce TE activity that may explain part of the new phenotypes observed. TEs may also play a role in the diploidization that follows polyploidization events. However, the extent to which TEs contribute to diploidization and fractionation bias remains unclear. Investigating the multiple factors controlling TE dynamics and the nature of ancient and recent polyploid genomes may shed light on these processes.
Collapse
Affiliation(s)
- Carlos M. Vicient
- Center for Research in Agricultural Genomics, CRAG (CSIC-IRTA-UAB-UB), Campus UAB, Cerdanyola del Vallès, 08193 Barcelona, Spain
- For correspondence. E-mail
| | - Josep M. Casacuberta
- Center for Research in Agricultural Genomics, CRAG (CSIC-IRTA-UAB-UB), Campus UAB, Cerdanyola del Vallès, 08193 Barcelona, Spain
| |
Collapse
|
18
|
Barker MS, Husband BC, Pires JC. Spreading Winge and flying high: The evolutionary importance of polyploidy after a century of study. AMERICAN JOURNAL OF BOTANY 2016; 103:1139-45. [PMID: 27480249 DOI: 10.3732/ajb.1600272] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 07/20/2016] [Indexed: 05/10/2023]
Affiliation(s)
- Michael S Barker
- Department of Ecology & Evolutionary Biology, University of Arizona, Tucson, Arizona 85721 USA
| | - Brian C Husband
- Department of Integrative Biology, University of Guelph, Guelph, Ontario N1G 2W1 Canada
| | - J Chris Pires
- Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211 USA
| |
Collapse
|