ABSTRACT: Natural epigenetic polymorphisms lead to intraspecific variation in Arabidopsis gene imprinting: small RNA-seq profiling in Arabidopsis thaliana Col, Ler, and Cvi parental and reciprocal F1 hybrid seeds
Project description:Imprinted gene expression occurs during seed development in plants and is closely tied to differential DNA methylation of maternal and paternal alleles, particularly at proximal transposable elements (TEs). Since the epigenetic modification of TEs can vary within species, we investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three strains of Arabidopsis that display diverse seed size phenotypes. Unexpectedly we found that one strain, Cvi, is globally CG hypomethylated. We discovered three examples of strain-specific imprinting caused by epigenetic variation at a TE. Our data allowed us to predict and experimentally validate an instances of allele-specific imprinting in additional strains based only on methylation patterns. We conclude that numerous differences in imprinting can evolve in highly similar, recently diverged genotypes due to epiallelic variation present within the species. Our data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds. Examination of parent-of-origin specific and total gene expression in embryo, endosperm, and whole seeds. Samples with the same heading are biological replicates (e.g. CVN1, CVN2, and CVN3). High throughput Illumina sequencing of poly-A selected RNA from Arabidopsis Col, Ler and Cvi reciprocal F1 hybrid embryo and endosperm tissue isolated at 6 days after pollination to identify imprinted genes.
Project description:Natural epigenetic polymorphisms lead to intraspecific variation in Arabidopsis gene imprinting: BS-seq of Arabidopsis thaliana Col, Ler, and Cvi parental and reciprocal F1 hybrid embryo and endosperm
Project description:Natural epigenetic polymorphisms lead to intraspecific variation in Arabidopsis gene imprinting: allele specific mRNA-seq expression profiling in Arabidopsis thaliana Col, Ler, and Cvi parental and reciprocal F1 hybrid embryo and endosperm
Project description:Imprinted gene expression occurs during seed development in plants and is associated with differential DNA methylation of parental alleles, particularly at proximal transposable elements (TEs). Imprinting variability could contribute to observed parent-of-origin effects on seed development. We investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three Arabidopsis strains with diverse seed phenotypes. The majority of imprinted genes were parentally biased in the same manner among all strains. However, we identified several examples of allele-specific imprinting correlated with intraspecific epigenetic variation at a TE. We successfully predicted imprinting in additional strains based on methylation variability. We conclude that there is standing variation in imprinting even in recently diverged genotypes due to intraspecific epiallelic variation. These data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds. Sequencing of 12 small RNA samples from whole seeds 6 days after pollination.
Project description:Imprinted gene expression occurs during seed development in plants and is associated with differential DNA methylation of parental alleles, particularly at proximal transposable elements (TEs). Imprinting variability could contribute to observed parent-of-origin effects on seed development. We investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three Arabidopsis strains with diverse seed phenotypes. The majority of imprinted genes were parentally biased in the same manner among all strains. However, we identified several examples of allele-specific imprinting correlated with intraspecific epigenetic variation at a TE. We successfully predicted imprinting in additional strains based on methylation variability. We conclude that there is standing variation in imprinting even in recently diverged genotypes due to intraspecific epiallelic variation. These data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds.
Project description:Imprinted gene expression occurs during seed development in plants and is associated with differential DNA methylation of parental alleles, particularly at proximal transposable elements (TEs). Imprinting variability could contribute to observed parent-of-origin effects on seed development. We investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three Arabidopsis strains with diverse seed phenotypes. The majority of imprinted genes were parentally biased in the same manner among all strains. However, we identified several examples of allele-specific imprinting correlated with intraspecific epigenetic variation at a TE. We successfully predicted imprinting in additional strains based on methylation variability. We conclude that there is standing variation in imprinting even in recently diverged genotypes due to intraspecific epiallelic variation. These data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds.
2014-07-08 | GSE52805 | GEO
Project description:Natural epigenetic polymorphisms lead to intraspecific variation in Arabidopsis gene imprinting
Project description:Imprinted gene expression occurs during seed development in plants and is associated with differential DNA methylation of parental alleles, particularly at proximal transposable elements (TEs). Imprinting variability could contribute to observed parent-of-origin effects on seed development. We investigated intraspecific variation in imprinting, coupled with analysis of DNA methylation and small RNAs, among three Arabidopsis strains with diverse seed phenotypes. The majority of imprinted genes were parentally biased in the same manner among all strains. However, we identified several examples of allele-specific imprinting correlated with intraspecific epigenetic variation at a TE. We successfully predicted imprinting in additional strains based on methylation variability. We conclude that there is standing variation in imprinting even in recently diverged genotypes due to intraspecific epiallelic variation. These data demonstrate that epiallelic variation and genomic imprinting intersect to produce novel gene expression patterns in seeds. Whole genome bisulfite sequencing of embryo and endosperm (14 samples).
Project description:Transcriptome and translatome analyses of 6 and 24 hours imbibed seeds dormant and non-dormant seeds of NILDOG1-Cvi with and without addition of the transcription inhibitor Cordycepin. NILDOG1-Cvi is the Ler WT containing an introgression of the Cvi accession on chromosome 5, which includes the DOG1 gene (Bentsink et al., 2006).
Project description:Arabidopsis thaliana seeds that maternally inherit a medea (mea) mutant allele abort before completing embryogenesis. However, mea seeds can be rescued by pollen from several natural ecotypes of A. thaliana, including the Cape Verdian accession Cvi-0. We developed a method for the mapping of parent-of-origin effects using whole-genome sequencing of segregant bulks. The strategy is to create an F2 population that contains one set of chromosomes from the maternal parent (mea, in a Ler background) but inherits two segregating sets (Ler and Cvi-0) from the other parent. The two paternally segregating sets have opposite effects in mea penetrance: Ler fathers allow full mea seed abortion, while Cvi fathers rescue 90% of medea seeds. Therefore, the two segregating paternal sets are not equally transmitted to the next generation. DNA extracted from pools of viable F2 seedlings was sequenced on an Illumina HiSeq 2000 platform, mapped to the reference TAIR10 A. thaliana genome and the ratio between Ler and Cvi-0 SNPs used to identify chromosomal regions enriched in Cvi-0 sequences. As a control, DNA pools extracted from crosses between a wild-type Ler mother and a hybrid Cvi-0:Ler father were also sequenced. Three biological replicates were made for each pool. Ler-1 x Ler-1:Cvi-0 hybrid viable seedlings pools (each is a biological replicate): WT_pool_1, WT_pool_2, WT_pool_3 mea-1/mea-1; MEA-GR x Ler-1:Cvi-0 hybrid viable seedlings pool (each is a biological replicate): mea_pool_1, mea_pool_2, mea_pool_3
