MeCP2 is predominantly expressed in neurons and suppresses astrocytic gene expression in oligodendrocytes when ectopically expressed. (A) Schematic representation of gfap locus (Upper). Methylation status of five CpG sites around the STAT3 binding site (black box), which is critical for LIF-induced activation of the gfap promoter, and of 30 CpG sites around the transcription initiation site (arrow) were examined for each cell type by bisulfite sequencing. Open and closed circles indicate unmethylated and methylated CpG sites, respectively. (B) MeCP2 expression (green) was examined in adult mouse brain sections. Neurons, oligodendrocytes, and astrocytes are identified with specific antibodies for NeuN (red, Upper middle), GST-π (red, center), and S100β (red, Lower middle), respectively. Staining of the hippocampal dentate gyrus region is shown. Insets: higher magnification views of square areas in each field. (Scale bar: 50 μm.) (C) MeCP2 is predominantly expressed in neurons. MeCP2 expression (green) was examined in the adult mouse cortex and corpus callosum. Oligodendrocytes, astrocytes, and neurons were identified with specific antibodies for GST-π (red, Upper rows), S100β (red, middle rows), and NeuN (red, Bottom rows), respectively. Insets: Hoechst nuclear images of each field. (Scale bar: 100 μm.) CTX, cortex; CC, corpus callosum. (D) EGFP-positive cells do not express MeCP2. MeCP2 expression (Upper Left) was observed in NeuN-positive (Upper Right) but not in EGFP-positive (Lower Left) cells. (E) MeCP2 (red) is expressed in Map2ab-positive neurons (Top, green), but not in RIP-positive oligodendrocytes (middle, green) or GFAP-positive astrocytes (Bottom, green) generated from AHPs in vitro. (Scale bar: 50 μm.) (F) Redundant expression of MBDs in vivo. Expression of MeCP2 (green, Left) and MBD1 (red, middle), another member of the MBD family, was examined in the adult hippocampal region. These two MBDs showed the same expression pattern (Right). (Scale bar: 100 μm.)