All sequences specific to genes imprinted in humans were individually reviewed to determine whether they have been reported as belonging to a DMR for which parent of origin marks are maintained by DNA methylation [59] [81].
After fertilization, these marks are maintained.
Additionally, after DNA replication is completed, epigenetic chromatin marks are maintained on the replicated sister chromatids.
Similar to what was observed in terminally differentiated cells derived from male embryos carrying a Tsix-truncated allele [ 15], we show in this report that such an accumulation of active chromatin marks is maintained, or even increased, during differentiation of Tsix-truncated cells (Additional file 4), correlating with Xist transcription upregulation [ 8, 12].
This mark is maintained at the break site until the break is repaired [ 18, 21].
Immunostaining against H3K27me3 in fixed GVs containing transplanted MEF nuclei revealed that the mark is maintained on the Xi of transplanted nuclei 3 days after nuclear transfer.
YEp352-based episomal plasmids marked with the URA3 gene [48] were maintained in transformed strains grown on synthetic defined SD-Ura medium consisting of 0.67% (wt/vol) yeast nitrogen base without amino acids, 2% (wt/vol) D-glucose, 3% (wt/vol) agar, with all supplements added except for uracil (Sigma-Aldrich Inc. MO USA).
Marker nomenclature for SSRs and SNPs were maintained according to their original publications (see Molecular Markers subsection).
By using a ChIP assay, we found that the association of Dnmt1 and Dnmt3a with the COX-2 promoter was significantly increased in F-IPFs compared with that in F-NLs under unstimulated conditions and marked, but not statistically significant, increases were maintained after cytokine stimulation (Fig. 3 B, C).
Marker sequences with a Tm value between 76 °C to 83 °C were maintained.
