(A) Runx2/p57 (left) and Bglap (right) mRNA levels are significantly upregulated during osteoblastic differentiation. MC3T3 cells treated with Ascorbic Acid (AA) 50ug/mL were collected at the indicated days and mRNA levels analyzed by RT-qPCR. mRNA expression values were normalized against Gapdh mRNA levels. (B) Alkaline phosphatase staining to determine osteoblast extracellular matrix maturation. (C-G) ChIP assays using antibodies against (C) H3Ac, (D) H3K4me3, (E) H3K27Ac, (F) H3K27me3 and (G) H4R3me2s performed at the indicated days of differentiation. Results are expressed as % Input ± SEM. Normal IgG was used as specificity control. Statistical analyses were performed with respect to 3 DIV. ***p<0.001, **p<0.01, ns = non-statistically significant differences.