Changes in gene expression after mechanical loading with and without satellite cell.

Skeletal muscle is a plastic tissue, adapting to different stimuli. Mechanical overload causes muscle hypertrophy and substantial changes in gene expression. We perform a time course analysis following synergistic ablation surgery to induce compensatory hypertrophy in the plantaris muscle in satellite cell depleted mice and wild-type mice. Microarray was used to determine the different expressed genes in skeletal muscle with or without satellite cell following mechanical overload. Mice were treated with tamoxifen to induce satellite cell (SC) depletion or vehicle (control). Following SC ablation, SC depleted mice (SC-) and satellite cell competent mice (SC+, or wild type) were subjected to mechanical overload of the plantaris muscle induced by synergist ablation surgery (removal of soleus and gastrocnemius tendon). Each experimental group had samples collected after 1, 3, 5 and 7 days post synergistic ablation in addition to a sham surgery control. Total RNA was isolated from n of 5-6 for each group per time point. For microarray analysis, samples were pooled with a total of n=2 per time point.