Fig. 1
From: Histone H3.3 sub-variant H3mm7 is required for normal skeletal muscle regeneration
H3mm7 is required for normal skeletal muscle regeneration and differentiation. a The H3mm7 gene is expressed in satellite cells. The colors of the tiles indicate the average expression level (n = 3) of H3 variants, satellite cell marker genes, and differentiation markers45 as the column-wise relative expression levels (Z-score). b Some of the fibers showed incomplete muscle regeneration in H3mm7−/− mice. Immunostaining of a regeneration marker (dMHC; red) and laminin (green) in TA muscle at 14 days after CTX injection. c CSA measurements of H3mm7−/− TA muscle fibers showed thinner fiber formation during muscle regeneration. The approximated fiber diameters of H3mm7+/+ and H3mm7−/− mice are shown as box plots (n = 177, 175, 231, 161, 179, 154, 156, 132, 153, 251, 138, 192, 141, 339 cells for individuals, respectively). The signs at the bottom indicate the observed number of dMHC-positive fibers (−: none, +: at least one, ++: >4). The medians, 25/75th percentiles, and 1.5 IQR (inter-quartile range) are employed to draw the box plots. d H3mm7−/− cells showed SK muscle differentiation deficiency in C2C12 cells and an H3mm7-rescued clone recovered SK muscle differentiation. Immunostaining of markers of fiber formation (MHC; red), rescued histone variants (GFP; green), and the nucleus (Hoechst; blue) in H3mm7−/− and H3mm7+/+ C2C12 cells are shown. e The loss of skeletal muscle marker gene expression levels was partially rescued by the H3mm7 expression. The expression levels relative to H3mm7+/+ at 48 h after differentiation stimuli were measured by RT-qPCR (n = 3). The error bars indicate ±1 SD. Two-sided Welch’s t-test was performed and the p-values are Ckm: 0.001, 0.042, 0.003, Des: 0.002, 0.064, 0.032 and Eef1a1: 0.159, 0.126, 0.031 (H3mm7+/+ vs. H3mm7−/−, H3mm7−/− vs. +H3mm7, H3mm7−/− vs. +H3.3 respectively). The scale bars in the immunostaining images are 100 µm
