It has previously been shown that the T>C variant in the ICR region affects OCT4/SOX2 binding, and our data can be interpreted to imply that the variant interferes with gonadal switching from paternal to maternal imprinting.
Intriguingly, any of several maternally inherited ICR mutations affected expression of the paternal AK029869 transcript in trans.
For nanopipets, ICR is affected by the tip diameter, surface charge of the tip, and cone angle of the pipet.
On the other hand our data also suggest that the effect of SYT-SSX is not limited to methylation changes at the H19 ICR but rather affects additional, hitherto undefined, regulatory mechanisms at the H19/IGF2 locus.
The value of ICR was greatly affected by the compaction force, and good reproducibility could be obtained only with compaction force above 200 N cm−2[5, 6]. Figure 1 Apparatus used to measure interfacial contact resistance.
Predictably, deletion of Zfp57 in ESCs also affects DNA methylation, with five tested ICRs (Snrpn, KvDMR, Rasgrf1, Peg3 and Gnas) being fully demethylated.
Despite the fact that ICRs are not all affected to the same extent in mutant Trim28 or Zfp57 embryos, the binding of TRIM28 and ZFP57 and the presence of H3K9me3, product of the histone methyltransferase SETDB1, were detected at all imprinted loci tested.
Methylation analysis of regions outside the H19 ICR showed that SYT-SSX1 does not affect methylation specifically and exclusively at the H19 ICR but rather at different discrete regions with even opposite effects in adjacent segments and in different hMSC populations.
Human ZFP57 mutations affect several maternally methylated ICRs while inactivation of the mouse Zfp57 causes imprinting defects at both maternally and paternally methylated loci.
