Fig. 3.

H3K27 methylation in undifferentiated and decidualizing HESC. A, Primary HESC treated with 8-Br-cAMP and MPA for the indicated time points were fixed in formaldehyde, stained, and subjected to confocal microscopy. The upper panel represents H3K27me3 staining (red channel), whereas the lower panel shows the corresponding nuclear DAPI staining (blue channel). B, Total protein lysates of HESC treated as above were subjected to Western blot analysis and immunoprobed for EZH1, H3K27me, and total H3. β-Actin was used as a loading control. C, Chromatin extracted from HESC first decidualized for 2, 4, or 8 d was immunoprecipitated with antibodies against H3K27me3 and IgG. The chromatin, normalized to the input, was analyzed by qPCR (ChIP-qPCR) with primers specific for the promoter regions of PRL (left panel) and IGFBP1 (right panel). Data are expressed as the fold change (±sem of triplicate measurements) relatively to the abundance of chromatin-bound H3K27me3 in untreated cells. The data shown in this figure are representative of three independent experiments.