Abstract:

The Dlk1-Dio3 imprinted domain on mouse chromosome 12 contains IG-DMR and Gtl2-DMR, whose methylation patterns are established in the germline and after fertilization, respectively. In this study, we determine that acquisition of DNA methylation at the paternal allele of the Gtl2-DMR is initiated after the blastocyst stage and completed by embryonic day 6.5, and that Gtl2 (approved symbol: Meg3) is monoallelically expressed from the maternal allele as early as the blastocyst. Therefore, DNA methylation at the Gtl2-DMR is not a prerequisite for the imprinted expression of Gtl2, which may be involved in the control of proliferation and differentiation of cells during early gestation. We also reveal that a subregion of the IG-DMR exhibits tissue-specific differences in allelic methylation patterns. These results add to the growing body of knowledge elucidating the mechanism whereby parent-of-origin-dependent DNA methylation at the IG-DMR leads to the imprinted expression of the Dlk1-Dio3 cluster.

日本語要旨:

胎盤発生と胎児発育に必須のゲノム領域のエピジェネティックな修飾状態を、バイオバンクリソースのヒト胎盤を用いて解析した。