Fig. 1

Reduced H3K9me3 staining at chromocenters in primary cultured astrocytes from C9BAC mice is accompanied by global loss of the H3K9me3 mark. a Representative confocal images of the immunofluorescence staining of H3K9me3 in primary cultures of control and C9BAC astrocytes. Nuclei are stained with DAPI. The images represent a maximum projection for the total nuclear volume. b Quantification of the mean nuclear signal staining intensity of H3K9me3 (upper graph) and DAPI (lower graph) shown as arbitrary units (a.u.). c Higher magnification of nuclei from control and C9BAC astrocytes immunostained for H3K9me3 (white and red) and stained for DAPI (white and green) are shown individually and merged. Images are single confocal sections. d Quantification of the number of H3K9me3-positive (upper graphs) and DAPI-positive foci (lower graphs) per nucleus. e Quantification of the fluorescence intensity of H3K9me3 (red) and DAPI (green) in a line scan drawn across chromocenters in nuclei from control and C9BAC astrocytes using a single confocal section. f Quantification of the nuclear area (μm²). In all graphs, bars represent mean ± SEM. *P< 0.05; non-statistical differences (ns), Student’s t test (n = 3 independent experiments, at least 30 cells were analyzed per condition in each experiment). g Western blot analysis of H3K9me3 from total nuclear lysates of control (lanes 1–3) and C9BAC (lanes 4–6) astrocytes from three independent experiments are shown. H3 was used as loading control. h Densitometric analysis of the western blot in g with H3K9me3 normalized to total H3 levels. Bars represent mean ± SEM. ***P< 0.001, Student’s t test