Fig. 2

LMCD1 increases fiber diameter, force, and resistance to fatigue. a Schematic representation of Green Fluorescent Protein (GFP) and LMCD1 adenovirus injection in each flexor digitorum brevis (FDB) muscle from 14-day-old SCID mice. b FDB mass normalized by mouse body weight after 7 days of GFP (control) or Lmcd1 expression (n = 6). c Isolated fiber diameter and representative microscopy image (× 200) in mice treated as in (b) (n = 10 mice, 15–18 fibers). Scale bar = 30 μm. d Force normalized by cross-sectional area (specific force) for the different frequencies tested (15–150 Hz) at 1-min intervals in mice treated as in (b) (n = 10 mice, 15–18 fibers). e Myoplasmic free Ca²⁺ concentrations for the different frequencies tested (15–150 Hz) at 1-min intervals in mice treated as in (b) (n = 10 mice, 15–18 fibers). f Mean value for specific force and myoplasmic free Ca²⁺ concentration for the different frequencies tested (15–150 Hz) at 1-min intervals, in mice treated as in (b) (n = 10 mice, 15–18 fibers). g Percentage of force relative to the first contraction. Peak force was measured at 70 Hz tetani of 350-ms duration given at 2-s intervals for 50 contractions in mice treated as in (b) (n = 10 mice, 15–18 fibers). h Percentage of myoplasmic free Ca²⁺ concentration normalized for the first contraction. Myoplasmic free Ca²⁺ concentration was measured as in (g) (n = 10 mice, 15–18 fibers). i Myoplasmic free Ca²⁺ concentrations at 150 Hz with caffeine treatment before and after fatigue protocol as in (g) (n = 10). Data is shown as mean ± SEM and *p < 0.05; **p < 0.01