Recapitulation of gametic DNA methylation and its post-fertilization maintenance with reassembled DNA elements at the mouse Igf2/H19 locus

摘要

Search for DNA sequences which are responsible for paternal methylation of the ICR fragment. Structure of the mouse endogenous locus. The expression of paternal and maternal genes depends on the shared 3′ enhancer. The ICR, located approximately at − 4 to − 2 kb relative to the transcription start site of gene is contained within a 2.9-kb SacI (Sa)-BamHI (B) fragment. DNA sequence (478 bp) shown to be sufficient for acquiring paternal methylation in TgM [15] is marked in gray. Dots (1–4) indicate CTCF-binding sites. G, BglII; H, HindIII sites. Structure of the 150-kb human β-globin locus YAC. The LCR and β-like globin genes are denoted as gray and filled boxes, respectively. In our previous studies, the ICR (2.9-kb) or the ICR4321S (766-bp shorter than the original 2.9-kb sequence) fragments were introduced 3′ to the LCR [11, 12]. In this study, a series of 5′-truncated ICR fragments (del-2–9) were inserted into the identical position of the YAC to examine their activities in TgM