ERK pathway inhibition by U0126 alters H3 and H4 acetylation profiles in the spinal cord of severe SMA-like mice. A–D, ChIP analysis of histone H3 (A, B) and H4 (C, D) acetylation in the ventral lumbar spinal cord of vehicle- and U0126-treated control mice at 2 and 6 d of age, vehicle-treated SMA-like mice at 2 d of age, and U0126-treated SMA-like mice at 2 and 6 d of age (n = 9). Quantitative real-time PCR was performed to detect SMN2 promoter site 1 (A, C) and site 2 (B, D). Data are displayed as mean ± SEM. *p < 0.05, **p < 0.01, ***p < 0.001.