F1 hybrids derived from a cross between two inbred parental lines often display widespread changes in DNA methylation and gene expression patterns relative to their parents. An emerging challenge is to understand how parental epigenomic differences contribute to these events. Here, we generated a large mapping panel of F1 epigenetic hybrids, whose parents are isogenic but variable in their DNA methylation patterns. Using a combination of multi-omic profiling and epigenetic mapping strategies we show that differentially methylated regions in parental pericentromeres act as major reorganizers of hybrid methylomes and transcriptomes, even in the absence of genetic variation. These parental differentially methylated regions are associated with hybrid methylation remodeling events at thousands of target regions throughout the genome, both locally (in cis) and distally (in trans). Many of these distally-induced methylation changes lead to nonadditive expression of nearby genes and associate with phenotypic heterosis. Our study highlights the pleiotropic potential of parental pericentromeres in the functional remodeling of hybrid genomes and phenotypes.
© 2024 Kakoulidou et al.