Altered expressions and DNA methylation of imprinted genes in chromosome 7 in brain of mouse offspring conceived from in vitro maturation

Abstract

ObjectivesThe aim of this research was to investigate the effects of in vitro maturation (IVM) on the expression of imprinted genes in offspring, and to identify possible regulatory mechanisms for these genes. ResultsBy using an IVM mouse model, mRNA expression of H19 was found down-regulated and Kcnq1ot1 was up-regulated in brains of IVM offspring. Of the differentially methylated regions (DMRs) of H19, CpG island 3 was found to have higher DNA methylation levels in IVM group compared with the control group; in contrast, Kcnq1ot1 showed a significant reduction in DNA methylation in IVM mice by using the bisulfite sequence PCR and pyrosequencing. However, Igf2 and Snrpn showed no significant differences in expression of mRNA or DNA methylation levels between the IVM and control groups. In conclusion, IVM could affect the expression of imprinted genes in the brains of IVM offspring, which could be induced by DNA methylation alterations.