Sox-Oct motifs contribute to maintenance of the unmethylated H19 ICR in YAC transgenic mice

作者：Sakaguchi Ryuuta; Okamura Eiichi; Matsuzaki Hitomi; Fukamizu Akiyoshi; Tanimoto Keiji^*

来源：Human Molecular Genetics, 2013, 22(22): 4627-4637.

DOI：10.1093/hmg/ddt311

Abnormal methylation at the maternally inherited H19 imprinted control region (H19 ICR) is one of the causative alterations leading to pathogenesis of BeckwithWiedemann syndrome (BWS). Recently, it was shown in human BWS patients, as well as mouse cell culture experiments, that Sox-Oct motifs (SOM) in the H19 ICR might play a role in protecting the maternal ICR from de novo DNA methylation. By grafting a mouse H19 ICR fragment into a human -globin yeast artificial chromosome (YAC) followed by analysis in transgenic mice (TgM), we showed previously that the fragment carried sufficient information to establish and maintain differential methylation after fertilization. To examine possible functions of the SOM in the establishment and/or maintenance of differential methylation, two kinds of YAC-TgM were generated in this study. In the SOM TgM, carrying the mouse H19 ICR bearing an SOM deletion, a maternally inherited transgenic ICR exhibited increased levels of methylation around the deletion site, in comparison to the wild-type control, after implantation. In the CTCF b (LCb) TgM, carrying a 2.3 kb DNA fragment supplemented with the fragment b including the SOM and four CTCF binding sites, maternally and some of the paternally inherited LCb fragments were significantly less methylated when compared with a control CTCF fragment that was supplemented only with additional CTCF sites; the CTCF was substantially methylated regardless of the parent of origin after implantation. These results demonstrated that the SOM in the maternal H19 ICR was required for maintaining surrounding sequences in the unmethylated state in vivo.

• 出版日期2013-11-15