Genome-wide identification, phylogeny, and gene duplication of the epigenetic regulators in Fagaceae

Epigenetic regulators are proteins involved in controlling gene expression. Information about the epigenetic regulators within the Fagaceae, a relevant family of trees and shrubs of the northern hemisphere ecosystems, is scarce. With the intent to characterize these proteins in Fagaceae, we searched for orthologs of DNA methyltransferases (DNMTs) and demethylases (DDMEs) and Histone modifiers involved in acetylation (HATs), deacetylation (HDACs), methylation (HMTs), and demethylation (HDMTs) in Fagus, Quercus, and Castanea genera. Blast searches were performed in the available genomes, and freely available RNA-seq data were used to de novo assemble transcriptomes. We identified homologs of seven DNMTs, three DDMEs, six HATs, 11 HDACs, 32 HMTs, and 21 HDMTs proteins. Protein analysis showed that most of them have the putative characteristic domains found in these protein families, which suggests their conserved function. Additionally, to elucidate the evolutionary history of these genes within Fagaceae, paralogs were identified, and phylogenetic analyses were performed with DNA and histone modifiers. We detected duplication events in all species analyzed with higher frequency in Quercus and Castanea and discuss the evidence of transposable elements adjacent to paralogs and their involvement in gene duplication. The knowledge gathered from this work is a steppingstone to upcoming studies concerning epigenetic regulation in this economically important family of Fagaceae.