De novo DNA methylation independent establishment of maternal imprint on X chromosome in mouse oocytes

Hatsune Chiba, Ryutaro Hirasawa, Masahiro Kaneda, Yuko Amakawa, En Li, Takashi Sado, Hiroyuki Sasaki

Research output: Contribution to journalArticlepeer-review

32 Citations (Scopus)


In female mouse embryos, the paternal X chromosome (Xp) is preferentially inactivated during preimplantation development and trophoblast differentiation. This imprinted X-chromosome inactivation (XCI) is partly due to an activating imprint on the maternal X chromosome (Xm), which is set during oocyte growth. However, the nature of this imprint is unknown. DNA methylation is one candidate, and therefore we examined whether disruptions of the two de novo DNA methyltransferases in growing oocytes affect imprinted XCI. We found that accumulation of histone H3 lysine-27 trimethylation, a hallmark of XCI, occurs normally on the Xp, and not on the Xm, in female blastocysts developed from the mutant oocytes. Furthermore, the allelic expression patterns of X-linked genes including Xist and Tsix were unchanged in preimplantation embryos and also in the trophoblast. These results show that a maternal disruption of the DNA methyltransferases has no effect on imprinted XCI and argue that de novo DNA methylation is dispensable for Xm imprinting. This underscores the difference between imprinted XCI and autosomal imprinting.

Original languageEnglish
Pages (from-to)768-774
Number of pages7
Issue number12
Publication statusPublished - 2008


  • DNA methylation
  • Genomic imprinting
  • Mouse
  • Oogenesis
  • X-chromosome in activation

ASJC Scopus subject areas

  • Genetics
  • Endocrinology
  • Cell Biology


Dive into the research topics of 'De novo DNA methylation independent establishment of maternal imprint on X chromosome in mouse oocytes'. Together they form a unique fingerprint.

Cite this