Epigenetic regulation of Igf2/H19 imprinting at CTCF insulator binding sites.

摘要: The mouse insulin-like growth factor II (Igf2) and H19 genes are located adjacent to each other on chromosome 7q11-13 reciprocally imprinted. It is believed that the allelic expression of these two regulated by binding CTCF insulators four parent-specific DNA methylation sites in an imprinting control center (ICR) between genes. Although monoallelically expressed peripheral tissues, Igf2 biallelically transcribed CNS. In this study, we examined Igf2/H19 CNS, hypothesizing aberrant as one mechanisms leads biallelic Using hybrid F1 mice (M. spretus males x C57BL/6 females), showed ICR were methylated exclusively paternal allele, bound only unmethylated maternal showing no differences from imprinted tissues. Among three epigenetic modifications examined, histone H3 lysine 9 correlated well with These results suggest alone not sufficient insulate promoter regulate gene thus challenging a common mechanism for lack Further studies should be focused identification factors involved CTCF-associated may needed coordinate imprinting.