Differential miRNA expression of inherently high- and low-active inbred mice. Mus musculus

To further our understanding of the biological mechanisms regulating voluntary physical activity levels, we measured differential miRNA expression in two strains of mice that have been repeatedly shown to have inherently high and low voluntary physical activity levels measured by wheel running. RNA from skeletal muscle (soleus and extensor digitorum longus (EDL)) and nucleus accumbens in the brain tissues were evaluated by microarray. There were no other variables besides inherent strain differences. Thirteen miRNAs from nucleus accumbens, 22 from soleus, and nine miRNAs from EDL were determined to be differentially expressed by microarray analysis. RT-qPCR validated mir-342b-3p and 466d-3p to be differentially expressed in the NA, and miR-466b-3p in the soleus. Overall design: Eight week 12 (6♂, 6♀) C57L/J and 12 (6♂, 6♀) C3H/HeJ mice were individually housed for 1 week with locked running wheel. At 9 weeks, animals were sacrificed and Soleus, Nucleus Accumbens, and EDL tissues were harvested and frozen. RNA from these tissues was extracted with Quiagen miRNeasy kit, column DNase purification, quality measured on bioanalyzer. Four samples from each tissue (male mice only) were used to differential miRNA analysis on microarray. No biological replicates used. Spike-in controls used in labeling and hybridization.