Ovulation Induction Changes Epigenetic Marks of Imprinting Genes in Mice Fetus Organs

Objective Genomic imprinting is an epigenetic phenomenon that plays a critical role in normal development of embryo. Using exogenous hormones during assisted reproductive technology (ART) can change an organism hormonal profile and subsequently affect epigenetic events. Ovarian stimulation changes gene expression and epigenetic pattern ofimprinted genes in the organs of mouse fetus.Materials and Methods For this experimental study, expression of three imprinted genes H19, Igf2 (Insulinlike growth factor 2) and Cdkn1c (Cyclindependent kinase inhibitor 1C), which have important roles in development of placenta and embryo, and the epigenetic profile of their regulatory region in some tissues of 19daysold female fetuses, from female mice subjected to ovarian stimulation, were evaluated by quantitative reversetranscription PCR (qRTPCR) and Chromatin immunoprecipitation (ChIP) methods.Results H19 gene was significantly lower in heart (P 0.05), liver (P 0.05), lung (P 0.01), placenta (P 0.01) and ovary (P 0.01). It was significantly higher in kidney of ovarian stimulation group compared to control fetuses (P 0.05). Igf2 expression was significantly higher in brain (P 0.05) and kidney (P 0.05), while it was significantly lower in lung of experimental group fetuses in comparison with control fetuses (P 0.05). Cdkn1c expression was significantly higher in lung (P 0.05). It was significantly decreased in placenta of experimental group fetuses rather than the control fetuses (P 0.05). Histone modification data and DNA methylation data were in accordance to the gene expression profiles.ConclusionResults showed altered gene expressions in line with changes in epigenetic pattern of their promoters in the ovarian stimulation group, compared to normal cycle.