Skeletal muscle satellite cells play key roles in postnatal muscle growth and 
regeneration. To study molecular regulation of satellite cells, we directly 
prepared satellite cells from 8- to 12-week-old C57BL/6 mice and performed 
genome-wide gene expression analysis. Compared with activated/cycling satellite 
cells, 507 genes were highly upregulated in quiescent satellite cells. These 
included negative regulators of cell cycle and myogenic inhibitors. Gene set 
enrichment analysis revealed that quiescent satellite cells preferentially 
express the genes involved in cell-cell adhesion, regulation of cell growth, 
formation of extracellular matrix, copper and iron homeostasis, and lipid 
transportation. Furthermore, reverse transcription-polymerase chain reaction on 
differentially expressed genes confirmed that calcitonin receptor (CTR) was 
exclusively expressed in dormant satellite cells but not in activated satellite 
cells. In addition, CTR mRNA is hardly detected in nonmyogenic cells. Therefore, 
we next examined the expression of CTR in vivo. CTR was specifically expressed 
on quiescent satellite cells, but the expression was not found on 
activated/proliferating satellite cells during muscle regeneration. CTR-positive 
cells reappeared at the rim of regenerating myofibers in later stages of muscle 
regeneration. Calcitonin stimulation delayed the activation of quiescent 
satellite cells. Our data provide roles of CTR in quiescent satellite cells and 
a solid scaffold to further dissect molecular regulation of satellite cells. 
Disclosure of potential conflicts of interest is found at the end of this 
article.