Questioning genetic supremacy: investigating the transmission of phenotypic traits and DNA methylation patterns across three generations in quails

Overview & Synopsis

Part of the environmental story of individuals lies within their DNA methylation (DNAm). Variations in the environment can trigger changes at the DNAm level and translate to phenotypic variability, even in the unexposed progeny of the individuals directly impacted. However, the amount of environmental information transmitted between generations via epigenetic phenomena is hardly quantifiable. The present study analyses DNAm from Reduced Representation Bisulfite Sequencing (RRBS) data for 1267 quails (Coturnix japonica) within three successive generations following an initial phytoestrogen ingestion. Among 112,561 CpG sites observed, we estimated an average heritability of DNAm of 0.24. After identification of differentially methylated regions (DMR) between control and treated groups in three consecutive generations, we conducted methylation quantitative trait loci (metQTL) analysis to identify regions that seem to escape genetic control. Using phenotypic data available on the same individuals, one can assess the portion of genetic and epigenetic determinism responsible for trait variability, and how it evolves across generations.