FIG. 5.

Protein levels and H3K27me3 pattern in nondifferentiated and differentiated mESCs. (A) Western blot data related to the levels of H3K27me3, exogenous and endogenous Oct4, HP1α, HP1β, and H3K9me3. Data were normalized to the total protein levels. Two possibilities of induction of differentiation were studied: 48 h of LIF withdrawal and 48 h of LIF withdrawal and ATRA treatment. (B) Accumulation of H3K27me3 appears at nuclear periphery (arrows) of nondifferentiated cells. After 48 h of ATRA differentiation, dense H3K27me3 signals were dispersed throughout the nuclei of differentiated cells. Reduced GFP-Oct4 levels were observed in differentiated cells relative to the nondifferentiated phenotype. Bars represent 15 μm. HP1, heterochromatin protein 1; LIF, leukemia inhibitory factor.