Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments.
Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments. Genomic DNA was extracted from whole-plant above-ground tissue of individual 25-day-old plants with the Qiagen DNeasy kit (Qiagen). DNA from two randomly chosen CVL39 individuals from ancestral (A3) lines and from 7 selected (S3) lines that had experienced 5 generations of selection in the three replicated dynamic landscapes (2xD1, 3xD5,2xD6) was sequenced (paired-end, 100 bp) using the Illumina Highseq 2000 Instrument. Single nucleotide polymorphisms and TE insertions were mapped with respect to the recombinant reference genome and compared between selected and ancestral lines.
Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments.
Project description:In Arabidopsis thaliana a high rate of spontaneous epigenetic variation can occur in the DNA methylome in the absence of genetic variation and selection. It has been of great interest, whether natural epigenetic variation is subject to selection and contributes to fitness and adaptation in selective environments. We compared the variation in selected phenotypic traits, genome-wide cytosine DNA methylation and gene expression in two Arabidopsis recombinant inbred lines, which had undergone five generations of selection in experimental landscapes relative to their genetically identical ancestors. Selected populations exerted significant differences in flowering time and the number of branches and fruits, differences that were maintained over two to three generations in the absence of selection. We identified 4,629 and 5,158 differentially methylated cytosines which were overrepresented in genes that regulate flowering time, epigenetic processes, development and morphogenesis. Differentially methylated genes were enriched in differentially expressed genes. Thus, epigenetic variation is subject to selection and may play an important role in the adaptive response of populations in rapidly changing natural environments.
Project description:Stochastic changes in cytosine methylation are a source of heritable epigenetic and phenotypic diversity in plants. Using the model plant Arabidopsis thaliana, we derive robust estimates of the rate at which methylation is spontaneously gained (forward epimutation) or lost (backward epimutation) at individual cytosines and construct a comprehensive picture of the epimutation landscape in this species. We demonstrate that the dynamic interplay between forward and backward epimutations is modulated by genomic context and show that subtle contextual differences have profoundly shaped patterns of methylation diversity in A. thaliana natural populations over evolutionary timescales. Theoretical arguments indicate that the epimutation rates reported here are high enough to rapidly uncouple genetic from epigenetic variation, but low enough for new epialleles to sustain long-term selection responses. Our results provide new insights into methylome evolution and its population-level consequences. MethylC-seq of Arabidopsis thaliana
Project description:Stochastic changes in cytosine methylation are a source of heritable epigenetic and phenotypic diversity in plants. Using the model plant Arabidopsis thaliana, we derive robust estimates of the rate at which methylation is spontaneously gained (forward epimutation) or lost (backward epimutation) at individual cytosines and construct a comprehensive picture of the epimutation landscape in this species. We demonstrate that the dynamic interplay between forward and backward epimutations is modulated by genomic context and show that subtle contextual differences have profoundly shaped patterns of methylation diversity in A. thaliana natural populations over evolutionary timescales. Theoretical arguments indicate that the epimutation rates reported here are high enough to rapidly uncouple genetic from epigenetic variation, but low enough for new epialleles to sustain long-term selection responses. Our results provide new insights into methylome evolution and its population-level consequences.
Project description:Genetic variation is regarded as a prerequisite for evolution. Theoretical models suggest epigenetic information inherited independently of DNA sequence can also enable evolution. However, whether epigenetic inheritance mediates phenotypic evolution in natural populations is unknown. Here we show that natural epigenetic DNA methylation variation in gene bodies regulates genes expression, and thereby influences the natural variation of complex traits in Arabidopsis thaliana. Notably, the effects of methylation variation on phenotypic diversity and gene expression variance are comparable with those of DNA sequence polymorphism. We also identify methylation epialleles in numerous genes associated with environmental conditions in native habitats, suggesting that intragenic methylation facilitates adaptation to fluctuating environments. Our results demonstrate that methylation variation fundamentally shapes phenotypic diversity in natural populations and provides an epigenetic basis for adaptive Darwinian evolution independent of genetic polymorphism.
Project description:This study used the mutants nrpe1-11 and ros1-4 to assess the impact of RNA-directed DNA methylation (RdDM) and ROS1 on the Arabidopsis thaliana (ecotype Col-0) methylome.