Fig. 3

Juvenile irradiated exercised soleus muscle displays a minor shift from type I to type IIa muscle fibers. Muscle fiber type analysis of EDL and soleus muscle from 3-month-old WT irradiated (Rad RL) and non-irradiated (Rad CL) mice after 1 month of VWR exercise (running) or sedentary control. a Muscle cross-sections from sedentary (left) and VWR exercised (right), non-irradiated contralateral (Rad CL) (top), and irradiated limb (Rad RL) (bottom) muscle. EDL sections (left) are labeled as such and appear primarily green with soleus sections (right) appearing primarily blue and red. Sections stained for type I (blue), type IIa (red), type IIb (green), and laminin (teal). Type IIx fibers are unstained and appear black. b Quantified fiber type distribution of muscle cross-sections from a for the b EDL and c soleus muscles. n = 3 mice for each condition. Two-way ANOVA with multiple comparisons. *p < 0.05, **p < 0.01. A significant interaction between variables was observed for soleus muscle fiber type data, p = 0.0006. Data displayed as mean ± s.e.m