title: Rate, spectrum, and evolutionary dynamics of spontaneous epimutations.
abstract: 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.
authors.affiliation: Groningen Bioinformatics Centre, University of Groningen, 9747 AG Groningen, The Netherlands;
authors.forename: Adriaan
authors.initials: A
authors.lastname: van der Graaf
authors.affiliation: Groningen Bioinformatics Centre, University of Groningen, 9747 AG Groningen, The Netherlands;
authors.forename: René
authors.initials: R
authors.lastname: Wardenaar
authors.affiliation: Department of Genetics, University of Georgia, Athens, GA 30602;
authors.forename: Drexel A
authors.initials: DA
authors.lastname: Neumann
authors.affiliation: European Institute for the Biology of Aging, University of Groningen, University Medical Centre Groningen, 9713 AV Groningen, The Netherlands; and.
authors.forename: Aaron
authors.initials: A
authors.lastname: Taudt
authors.affiliation: Department of Ecology, Evolution and Behavior, University of Minnesota, Minneapolis, MN 55455.
authors.forename: Ruth G
authors.initials: RG
authors.lastname: Shaw
authors.affiliation: Groningen Bioinformatics Centre, University of Groningen, 9747 AG Groningen, The Netherlands;
authors.forename: Ritsert C
authors.initials: RC
authors.lastname: Jansen
authors.affiliation: Department of Genetics, University of Georgia, Athens, GA 30602; schmitz@uga.edu m.colome.tatche@umcg.nl frank@johanneslab.org.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Schmitz
authors.affiliation: European Institute for the Biology of Aging, University of Groningen, University Medical Centre Groningen, 9713 AV Groningen, The Netherlands; and schmitz@uga.edu m.colome.tatche@umcg.nl frank@johanneslab.org.
authors.forename: Maria
authors.initials: M
authors.lastname: Colomé-Tatché
authors.affiliation: Groningen Bioinformatics Centre, University of Groningen, 9747 AG Groningen, The Netherlands; schmitz@uga.edu m.colome.tatche@umcg.nl frank@johanneslab.org.
authors.forename: Frank
authors.initials: F
authors.lastname: Johannes
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D002843:Chromatin / Q000235:genetics; D019175:DNA Methylation; D018744:DNA, Plant / Q000235:genetics; D044127:Epigenesis, Genetic; D019143:Evolution, Molecular; D014644:Genetic Variation; D018745:Genome, Plant; D008957:Models, Genetic; D009154:Mutation; D012641:Selection, Genetic; D013997:Time Factors
chemical_list: D002843:Chromatin; D018744:DNA, Plant
keywords: Arabidopsis; DNA methylation; epigenetics; epimutation; evolution