Pre-implantation alcohol exposure induces lasting sex-specific DNA methylation programming errors in the developing forebrain

Prenatal alcohol exposure is recognized to alter DNA methylation profiles of brain cells during development, and as being part of the molecular basis underpinning Fetal Alcohol Spectrum Disorder (FASD) etiology. However, we have negligible information on the effects of alcohol during the initial embryonic stages, a window marked with dynamic DNA methylation reprogramming, and on how this may rework  the brain developmental program. Using a pre-clinical in vivo mouse model, we show that pre-implantation alcohol exposure leads to adverse developmental outcomes that replicate clinical facets observed in children with FASD. Genome-wide DNA methylation analyses of fetal forebrains uncovered sex-specific alterations, including partial loss of DNA methylation maintenance at imprinted control regions, and abnormal re-establishment of de novo DNA methylation profiles in various biological pathways (e.g, neural/brain development). These findings support the contribution of alcohol-induced DNA methylation programming deviations during pre-implantation to the manifestations of neurodevelopmental phenotypes associated with FASD. RRBS analyses of E10.5 mouse embryo forebrain