Project description:Plants of different ploidy levels are separated by a strong postzygotic hybridization barrier that is established in the endosperm. Deregulated parent-of-origin specific genes are causal for the response to interploidy hybridizations, revealing an epigenetic basis of this phenomenon. In this study we present evidence that paternal hypomethylation can bypass the interploidy hybridization barrier by alleviating the requirement of the epigenetic Polycomb Repressive Complex 2 (PRC2) in the endosperm. Bypass of the barrier is mediated by suppressed expression of imprinted genes. We show that hypomethylated pollen causes redistribution of CHG methylation to PRC2 target genes, revealing that different epigenetic modifications can functionally substitute for each other. Our work presents a method and the underlying mechanism for the generation of viable triploids, providing an impressive example for the potential of epigenome manipulations for plant breeding. Examination of DNA methylation in Arabidopsis endosperm, embryo, and pollen, and gene expression in seeds
Project description:Ecotype-specific differences in genome methylation were assayed in Arabidopsis Col and Ler variations using genomic tiling microarrays. Comparative genome hybridization was also performed so that the contribution of ecotype-specific amplifications and deletions could be estimated and integrated into the analysis of differential DNA methylation. Keywords: methylation analysis and comparative genome hybridization
Project description:Histone 3 lysine 4 and histone 3 lysine 9 methylation in wild type and ddm1 Arabidopsis thaliana seedlings. The purpose of the chromatin immunoprecipitation/microarray (ChIP/chip) experiment is to determine which regions of a genome are enriched for a particular histone modification in a single Arabidopsis thanliana genotype. Chromatin immunoprecipitation with antibodies raised against dimethyl histone-H3 lysine-9 (H3mK9) or dimethyl histone-H3 lysine-4 (H3mK4) is performed on a selected genotype. This purified DNA from each immunoprecipiation (mH3K9, mH3K4, no antibody control) is used for random amplification to increase the quantity of DNA for microarray hybridization. The amplified DNA from each experimental sample is then labeled with Cy5 and hybridized against total input DNA from the corresponding genotype, labeled in Cy3. In a single hybridization, the total input DNA serves as a baseline and is compared to the immunoprecipitated samples. Ratios of normalized signal intensities were calculated to identify enrichment of a particular sequence after immunoprecipitation, in comparison to the total input DNA. Dye swap analysis is carried out to take account of experimental variation by repeating the hybridization with identical samples labeled with Cy3 and Cy5, respectively. This SuperSeries is composed of the SubSeries listed below.
Project description:Hybrid matings between A. thaliana and A. arenosa result in post zygotic seed lethality resulting in hybridization barrier between the two species. This barrier can be overcome to a large degree by increasing the genome dosage of the maternal genome (i.e. A. thaliana) in a cross between the two species. In this experiment we assayed the transcriptome of an incompatible cross (2x At x 2x Aa) with high seed lethality and a compatible cross (4x At x 2x Aa) using silique tissue at 5 days after pollination. We used microarrays to identify dosage responsive gene in interspecies hybridization Keywords: differential expression
Project description:DNA methylation in wild type bolting plants, wild type seedlings, and ddm1 seedlings. The purpose of the McrBC methylation microarray assay is to determine which regions of a genome are methylated versus those that are unmethylated in a single Arabidopsis thanliana genotype. McrBC is a methylation-sensitive enzyme that restricts DNA only at purine-Cmethyl half sites when separated between 50bp and 3kb. A designated amount of DNA from a particular genotype is sheared to a size range of 1kb-10kb using nebulization. We restrict half of the nebulized DNA with McrBC, and the methylated fraction is then removed from the unmethylated fraction through gel purification of DNA fragments greater than 1kb.* The remaining nebulized DNA is subjected to the same gel purification scheme, but with no McrBC treatment. In a single hybridization, the untreated sample is labeled with Cy5 and the McrBC-treated sample with Cy3. Thus, after labeling and microarray hybridization, the ratio of normalized Cy5 to normalized Cy3 represents the relative methylation at the sequence represented by the spot on the microarray. Dye swap analysis is carried out to take account of experimental variation by repeating the hybridization with identical samples labeled with Cy3 and Cy5, respectively. This SuperSeries is composed of the SubSeries listed below.
Project description:a2e_heterosis - cgh_colvsc24_wg - Arabidopsis thaliana accessions (Col-0, C24 and Cvi) and their hybrid were used to investigate the dynamics of the epigenome after intraspecific hybridization between - Comparative genome hybridization between Arabidopsis thaliana accessions Col-0 and C24.
Project description:a2e_heterosis - cgh_colvscvi_wg - Arabidopsis thaliana accessions (Col-0, C24 and Cvi) and their hybrid were used to investigate the dynamics of the epigenome after intraspecific hybridization between - Comparative genome hybridization between Arabidopsis thaliana accessions Col-0 and CVi.