Assisted reproductive technologies, including in vitro fertilization (IVF), are now frequently used, and increasing evidence indicates that IVF causes gene expression changes in children and adolescents that increase the risk of metabolic diseases. Although such gene expression changes are thought to be due to IVF-induced epigenetic changes, the mechanism remains elusive. We tested whether the transcription factor ATF7-which mediates stress-induced changes in histone H3K9 tri- and dimethylation, typical marks of epigenetic silencing-is involved in the IVF-induced gene expression changes. IVF up- and downregulated the expression of 688 and 204 genes, respectively, in the liver of 3-week-old wild-type (WT) mice, whereas 87% and 68% of these were not changed, respectively, by IVF in ATF7-deficient (Atf7-/- ) mice. The genes, which are involved in metabolism, such as pyrimidine and purine metabolism, were upregulated in WT mice, but not in Atf7-/- mice. Of the genes whose expression was upregulated by IVF in WT mice, 37% were also upregulated by a loss of ATF7. These results indicate that ATF7 is a key factor in establishing the memory of IVF effects on metabolic pathways.
Keywords: ATF7; epigenetic change; gene expression change; in vitro fertilization; memory; stress.