Figure 3
From: Oxidative stress, mitochondrial damage, and cores in muscle from calsequestrin-1 knockout mice
Unstructured and contracture cores in EDL muscle fibers from aged CASQ1-null mice. (A, C) Histological examination by light microscopy of EDL muscle fibers at 27 months of age. While fibers from WT mice maintain a well-preserved cross-striation pattern (A), fibers from CASQ1-null mice often exhibit regions of degeneration ((C), stars) classified as unstructured cores. (B, D) Immuno-fluorescence imaging with anti-RYR1 antibody shows loss of the precise double-row cross-striations (visible in WT, inset in (B) in fibers from CASQ1-null mice (inset in (D)). (E, F) Both histology (E) and electron microscopy (F) revealed the presence in some fibers of confined areas of contracture (empty arrows), defined as contracture cores, which are frequent in fibers from CASQ1-null mice. See Figure 1 and Additional file 3: Table S1 for detailed quantitative analyses. Scale bars: (A-E), 5 μm; (F), 1 μm; insets, 2 μm. EDL, extensor digitorum brevis; CASQ1, skeletal isoform of calsequestrin; RYR, ryanodine receptor; WT, wild type.