Fig. 3: H3.1 enrichment at chromocenters requires SVM motif and is compromised in Suv39h dn ESCs.

a Left: Specific aminoacid residues are depicted for H3.1/2 (purple) and H3.3 (green) and grouped based on their similarities with the histone chaperone recognition motif (SVM or AIG). Aminoacid substitutions from original sequences are boxed. Right: experimental scheme b Representative epifluorescence images of H3-SNAP-Tag histones (red) in ESCs along with DNA counterstaining (DAPI, cyan). Scale bar 10 μm. c Quantification of cells exhibiting H3 patterns at PHC during Early, Mid, and Late S stages. Stacked histograms show the mean (in %) and bars s.d. from 3 experiments for all constructs exept H3.2 with 2 experiments. n = 115 for H3.1; 297 for H3.3; 120 for H3.2; 351 for H3.1 A31S; 186 for H3.3 S31A; 182 for H3.3 S31D. Source data are provided as a Source Data file. d left: Representative epifluorescence images of endogenous H3.1/H3.1 (Red) and H3.3 (Green) co-stained in WT and Suv39h dn ESCs along with DNA counterstaining (DAPI, cyan). Scale bar, 10 µm. Right: boxplots showing the ratio of H3.1/2 (magenta) and H3.3 (green) immunofluorescence signal inside and outside of pericentric heterochromatin (PHC) in WT and Suv39h dn cells from 4 experiments. The center of the boxplot is the median, the bounds of the box are the 1st and 3rd quartiles, dots are outliers, and the whiskers extend to 1.5x IQR. For ESC WT n = 244 for H3.1 and 218 for H3.3; for Suv39h dn ESCs n = 294 for H3.1 and 155 for H3.3. Mann–Whitney two-tailed was used: **** = p value < 0.0001, *** = p value < 0.001, ns non-significant = p value > 0.05. P values: H3.1 ES WT vs. H3.3 ES WT < 1.e⁻¹⁵; H3.1 ES WT vs. H3.1 Suv39dn < e⁻¹⁵; H3.1 ES WT vs. H3.3 Suv39dn < e⁻¹⁵; H3.3 ES WT vs. H3.1 Suv39dn = 0.00022247; H3.3 ES WT vs. H3.3 Suv39dn = 0.68257230; H3.1 in Suv39dn vs. H3.3 in Suv39dn = 0.2479430. Source data are provided as a Source Data file.