Preimplantation embryo ketone body exposure exerts sex-specific effects on mouse fetal and placental transcriptomes

Ketogenic diet consumption elevates circulating levels of the ketones ß-hydroxybutyrate (ßOHB) and acetoacetate (AcAc). In vitro ketone exposure perturbs preimplantation mouse embryo viability and female-specific fetal development post-transfer. Here we assessed whether transient exposure of preimplantation embryos to ketones impacts post-implantation fetal and placental gene expression. Blastocysts cultured in vitro with or without 2 mmol/L ßOHB alone ('ßOHB') or combined with 0.8 mmol/L AcAc ('Keto') underwent embryo transfer. Transcriptional profiles of sexed E14.5 placentae, liver, and brain were examined via RNA-Seq and DAVID functional analysis, revealing a sexually dimorphic transcriptomic response. ßOHB and Keto exposure both downregulated genes related to oxidative phosphorylation specifically in female liver. ßOHB downregulated female placental steroid biosynthetic processes, while Keto treatment upregulated genes relevant to blood vessel formation and cell migration in male placentae. Brain transcriptomes were minimally affected. X-linked genes and chromatin modifiers were identified as differentially expressed, alluding to a sex-specific regulatory mechanism. Transient preimplantation ketone exposure therefore perturbs sex-specific fetal liver and placental gene expression demonstrating a developmental programming effect that warrants future investigation of male and female offspring postnatal metabolic health. Overall design: mRNA profiles of male and female D14.5 murine fetal liver, fetal brain and placental tissues cultured in vitro with 2 mM ßOHB versus control, or 0.8 mM AcAc + 2 mM ßOHB versus control.