Genomic imprinting of Xist by maternal H3K27me3. Mus musculus

Maternal imprinting at the Xist gene is essential to achieve paternal allele-specific imprinted X chromosome inactivation (XCI) in female mammals. However, the mechanism underlying the Xist imprinting is unclear. Here we show that the Xist gene is coated with H3K27me3 in mouse oocytes, which persists through preimplantation development. Ectopic removal of H3K27me3 induces maternal Xist expression and maternal XCI, indicating that maternal H3K27me3 is the imprinting mark of Xist. Overall design: Examination of gene expression in 1 cell types.