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PROVIDER: PRJNA377704 | ENA |
REPOSITORIES: ENA
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Project description:Subgenome dominance in an interspecific hybrid, synthetic allopolyploid, and a 140 year old naturally established neo-allopolyploid monkeyflower
| PRJNA378427 | ENA
Project description:The importance and applications of polyploidy have long been recognized, from shaping the evolutionary success of flowering plants to improving agricultural productivity. Recent studies have shown that one of the parental subgenomes in ancient polyploids is generally more dominant - having both retained more genes and being more highly expressed - a phenomenon termed subgenome dominance. How quickly one subgenome dominates within a newly formed polyploid, if immediate or after millions of years, and the genomic features that determine which genome dominates remain poorly understood. To investigate the rate of subgenome dominance emergence, we examined gene expression, gene methylation, and transposable element (TE) methylation in a natural less than 140 year old allopolyploid (Mimulus peregrinus), a resynthesized interspecies triploid hybrid (M. robertsii), a resynthesized allopolyploid (M. peregrinus), and diploid progenitors (M. guttatus and M. luteus). We show that subgenome expression dominance occurs instantly following the hybridization of two divergent genomes and that subgenome expression dominance significantly increases over generations. Additionally, CHH methylation levels are significantly reduced in regions near genes and within transposons in the first generation hybrid, intermediate in the resynthesized allopolyploid, and are repatterned differently between the dominant and submissive subgenomes in the natural allopolyploid. Our analyses reveal that the subgenome differences in levels of TE methylation mirror the increase in expression bias observed over the generations following the hybridization. These findings not only provide important insights into genomic and epigenomic shock that occurs following hybridization and polyploid events, but may also contribute to uncovering the mechanistic basis of heterosis and subgenomic dominance.
2018-05-23 | GSE95799 | GEO
Project description:Evolution and adaptation of living organisms are results of permanent fights against diverse threats, which imply specific responses from the genome itself. Allopolyploidy, combining interspecific hybridization with whole genome duplication, is recognised as an important evolutionary force in plants. Its evolutionary success can be related to the rapid and profound genome reorganizations generated in response to the “Genome Shock” that allow the neo-allopolyploid to adapt efficiently to new environments. While work has focused on the structural and functional consequences of allopolyploidy, studies dedicated to the response of the neo-allopolyploid genome at the level of the functional regulation of genome expression have been rarely conducted. Recently, the hypothesis of a major role for small non coding RNAs (sRNAs) in mediating the immediate functional response of neo-allopolyploid genomes has progressively emerged. Here, we characterize the global response of sRNAs to allopolyploidy in Brassica, using three independent resynthesized B. napus allotetraploids surveyed at two different generations in comparison with their diploid progenitors, by high-throughput sequencing of sRNAs. Our evidence suggests an immediate but transient response of specific sRNA populations, targeting non-coding components of the genome. We identify the early accumulation of both 21- and 24-nt sRNAs involved in the regulation of the same targets, supporting a PTGS-to-TGS shift at the first stages of the neo-allopolyploid formation. We propose that sRNAs are early mobilized in response to allopolyploidy to control the unexpected transcriptional reactivation of various non-coding elements thus, playing the role of guardians of genome integrity during the first steps of neo-allopolyploid formation.
2017-09-15 | GSE94076 | GEO
Project description:The fate of doubled genes, from allopolyploid or autopolyploid origin, is controlled at multiple levels within the central dogma: gene loss or silencing, neo- and/or sub functionalization, inter genomic transfer, allele dominance/co-dominance, differences in transcription/translation efficiency, post translational modifications… These regulatory processes through evolution have caused a plethora of genotype x environment interactions displayed in the modern day phenotypes. The study of non-model crops is challenging but solutions are emerging. More and more, one gets insight into the tolerance mechanisms of a specific genotype. By integrating transcriptomics into our proteomic data, we studied the genetic diversity of an allopolyploid ABB banana, a tolerant genotype, and compared it to two different sensitive AAA genotypes. The root growth of the ABB cultivar was 60 % higher under mild osmotic stress. 234,000 spectra were aligned and quantified, resulting in 2,753 identified root proteins. 383 gene loci displayed genotype specific differential expression whereof 252 showed at least one Single Amino Acid Polymorphism (SAAP). The homeoallelic contribution was assessed using transcriptome read alignment, thus revealing each allele contribution at the RNA level. This provides insight in the structure and the organization of the triploid genome. In the ABB cultivar, allele expressions are supposed to follow a 1/3 and 2/3 pattern. We found that many genes deviated from this expectation and we show that 32 gene loci even displayed a 100% read preference for the allele that was unique for the ABB tolerant genotype , suggesting that the presence of unique alleles and homoelog expression bias is correlated to the observed phenotype.
2018-01-29 | PXD006375 | Pride
Project description:Allopolyploidy, entailing whole genome duplication (WGD) of merged divergent genomes of different species, often instigates transcriptome shock, whereby both total gene expression level and homeolog expression partitioning can be disrupted and remodeled. Little is known about the extent to which the parental expression-conserved genes will be disrupted/remodeled by allopolyploidization, nor the evolutionary relevancy of shock-induced expression repatterning. Here, by microarray-based gene expression profiling and gene-specific cDNA-pyrosequencing, we assessed transgenerational transcriptome shock in a synthetic allotetraploid wheat (AT2) with karyotype and basic morphology mimicking those of natural tetraploid wheat, Triticum turgidum. We show that the transcriptome shock in AT2 is exceptionally strong that it disrupted intrinsically conserved parental gene expression, and resulted in extensive expression nonadditivity in the newly formed allotetraploid plants. At total expression level, a substantial proportion of shock-induced novel expression, especially over-transgressive expression, was rapidly stabilized already in early generations of AT2. Extensive remodeling of homeolog expression occurred in AT2, including those genes that showed additive total expression, and which generated subgenome expression dominance, a pattern that mirrors T. turgidum. Thus, the shock-induced new patterns of gene expression at both the total expression level and subgenome homeolog partitioning showed evidence of evolutionary persistence. Complex relationships between homeolog expression remodeling and nonadditive total expression were observed in a tissue-specific manner. We have 9 samples including two tissues, leaf and young-inflorescence, respectively. Each sample has three replicates. So we overall have 54 samples.
2016-02-12 | E-GEOD-65844 | biostudies-arrayexpress
Project description:Background: Polyploidy has long been recognized as an important mechanism in eukaryotes evolution. Recent studies have documented dynamic changes in plant polyploid gene expression, which reflects genomic and functional plasticity of duplicate genes and genomes in plants. Genomewide approaches in a variety of allopolyploids, mostly synthetics, reveal a trend of non-additive gene expression. The aim of the study was to document expression divergence between a relatively recently formed natural allopolyploid (Coffea arabica) and its ancestral parents (Coffea canephora and Coffea eugenioides) and to verify if the divergence was ‘environment-dependent’.Results: Employing a microarray platform designed against 15,522 unigenes, we assayed gene expression levels in allopolyploid and its two parental diploids. For each gene, we determined expression variation levels between the three species grown under two sets of temperature conditions (26-22°C/30-26°C). More than 35% of genes were differentially expressed in each comparison at both temperatures, except for ‘allopolyploid versus Canephora’ at the ‘hottest’ temperature where an unexpected low gene expression divergence (<9%) were observed. Genes were binned in categories: ‘no change’, ‘additivity’, ‘transgressive’ and ‘dominance’ (‘Canephora-like’ and ‘Eugenioides-like’). The totally new phenomenon revealed by our study was a drastic modification of proportions between the allopolyploid and its parents when environmental conditions were modified. At the ‘hottest’ temperature, we found a virtual disappearance of gene categories classed as ‘transgressive’, ‘Eugenioides-like dominance’ or ‘additivity’ and a major increase in genes classed in the ‘Canephora-like dominance’ category. At this set of growing conditions, we therefore found very high bias that suggested a phenomenon of ‘dominance’ of C. canephora transcription profile. The Canephora genome parental expression state seems exhibited in strong preference to the Eugenioides genome parental state. Conclusion: Our data constitute evidence for a transcription profile divergence between allopolyploid and its parental species, massively affected by environmental conditions. The parental origin of the transcription profiles was not consistently biased towards one parental species, but appeared to be affected by environmental conditions. This phenomenon indicates the plasticity of allopolyploids and might ultimately explain better adaptation to environmental conditions.
2011-10-12 | GSE24682 | GEO
Project description:Transcriptomic changes following recent natural hybridization and allopolyploidy in the salt marsh species Spartina x townsendii and Spartina anglica (Poaceae) Allopolyploidy results from two events: the merger of divergent genomes and genome duplication. Both events have important functional consequences for the evolution and adaption of newly formed allopolyploid species. In spite of significant progress made the last years, a few studies have decoupled the effects of hybridization from genome duplication in the observed patterns of expression changes accompanying allopolyploidy in natural conditions. We used Agilent Rice oligo-microarrays to explore gene expression changes following allopolyploidy in Spartina that includes a classical example of recent allopolyploid speciation, S. anglica formed during the 19th century following genome duplication of the hybrid S. x townsendii. Our data indicate important, thought different effects of hybridization and genome duplication in the expression patterns of the hybrid and allopolyploid. Deviation from parental additivity was most important following hybridization and was accompanied by maternal expression dominance, although transgressively expressed genes were also encountered. Maternal dominance is attenuated following genome duplication in S. anglica while this species exhibits an increased number of transgressively over expressed genes. These results reflect the decoupled effects of the “genomic shock” following hybridization and genome redundancy, on the genetic, epigenetic and regulatory mechanisms characterizing transcriptomic evolution in allopolyploids. We used Agilent Rice oligo-microarrays to explore gene expression changes among Spartina species, following interspesific hybridization and genome duplication (allopolyploidy). The analysed species included the parents S. maritima & S.alterniflora, the hybrid F1 S x. towensendii and the allopolyploid S.anglica. A total of 20 slides (five replicates per species) were hybridized on a 44 K Rice Agilent array using a one color desgin.
2010-11-10 | E-GEOD-18961 | biostudies-arrayexpress
Project description:Transcriptomic changes following recent natural hybridization and allopolyploidy in the salt marsh species Spartina x townsendii and Spartina anglica (Poaceae) Allopolyploidy results from two events: the merger of divergent genomes and genome duplication. Both events have important functional consequences for the evolution and adaption of newly formed allopolyploid species. In spite of significant progress made the last years, a few studies have decoupled the effects of hybridization from genome duplication in the observed patterns of expression changes accompanying allopolyploidy in natural conditions. We used Agilent Rice oligo-microarrays to explore gene expression changes following allopolyploidy in Spartina that includes a classical example of recent allopolyploid speciation, S. anglica formed during the 19th century following genome duplication of the hybrid S. x townsendii. Our data indicate important, thought different effects of hybridization and genome duplication in the expression patterns of the hybrid and allopolyploid. Deviation from parental additivity was most important following hybridization and was accompanied by maternal expression dominance, although transgressively expressed genes were also encountered. Maternal dominance is attenuated following genome duplication in S. anglica while this species exhibits an increased number of transgressively over expressed genes. These results reflect the decoupled effects of the “genomic shock” following hybridization and genome redundancy, on the genetic, epigenetic and regulatory mechanisms characterizing transcriptomic evolution in allopolyploids.
2010-11-10 | GSE18961 | GEO
Project description:Allopolyploidy, entailing whole genome duplication (WGD) of merged divergent genomes of different species, often instigates transcriptome shock, whereby both total gene expression level and homeolog expression partitioning can be disrupted and remodeled. Little is known about the extent to which the parental expression-conserved genes will be disrupted/remodeled by allopolyploidization, nor the evolutionary relevancy of shock-induced expression repatterning. Here, by microarray-based gene expression profiling and gene-specific cDNA-pyrosequencing, we assessed transgenerational transcriptome shock in a synthetic allotetraploid wheat (AT2) with karyotype and basic morphology mimicking those of natural tetraploid wheat, Triticum turgidum. We show that the transcriptome shock in AT2 is exceptionally strong that it disrupted intrinsically conserved parental gene expression, and resulted in extensive expression nonadditivity in the newly formed allotetraploid plants. At total expression level, a substantial proportion of shock-induced novel expression, especially over-transgressive expression, was rapidly stabilized already in early generations of AT2. Extensive remodeling of homeolog expression occurred in AT2, including those genes that showed additive total expression, and which generated subgenome expression dominance, a pattern that mirrors T. turgidum. Thus, the shock-induced new patterns of gene expression at both the total expression level and subgenome homeolog partitioning showed evidence of evolutionary persistence. Complex relationships between homeolog expression remodeling and nonadditive total expression were observed in a tissue-specific manner.
2016-02-12 | GSE65844 | GEO
Project description:Alteration in gene expression accompanying initial stages of allopolyploidy is a prominent feature in plants, but its spectrum and model are highly idiosyncratic. We used multi-colour GISH to identify individuals from two nascent allohexaploid wheat lines between Triticum turgidum and Aegilops tauschii, which had a transgenerationally stable chromosomal constitution mimicking that of common wheat. We performed genomewide analysis of gene expression for these plants along with their parental species using the Affymetrix GeneChip Wheat Genome-Array. Comparison with parental species coupled with inclusion of empirical mid-parent values (MPVs) revealed two patterns of alteration in gene expression in the allohexaploid lines: parental dominance expression and nonadditive expression. Genes involved in each altered pattern could be classified into three distinct groups, stochastic, heritable and persistent, based on their transgenerational heritability and inter-line conservation. Whereas both altered patterns of gene expression showed a propensity of inheritance, identity of the involved genes is stochastic, consistent with the involvement of diverse Gene Ontology (GO) terms. Nonetheless, those genes showing nonadditive expression exhibited a significant enrichment for vesicle-function. Our results suggest global alteration in gene expression conditioned by nascent allopolyploidy likely play functional roles in stabilization and establishment of the newly formed plants, and consequential to evolution. We used Affymetrix GeneChip Wheat Genome-Array to compare the expression difference of newly synthetic wheat allopolyploid lines and their parental lines.
2012-04-30 | E-GEOD-29882 | biostudies-arrayexpress