Pax7 is critical for the normal function of satellite cells in adult skeletal muscle

Extensive analyses of mice carrying null mutations in paired box 7 (Pax7) have confirmed the progressive loss of the satellite cell lineage in skeletal muscle, resulting in severe muscle atrophy and death. A recent study using floxed alleles and tamoxifen-induced inactivation concluded that after 3 wk of age, Pax7 was entirely dispensable for satellite cell function. Here, we demonstrate that Pax7 is an absolute requirement for satellite cell function in adult skeletal muscle. Following Pax7 deletion, satellite cells and myoblasts exhibit cell-cycle arrest and dysregulation of myogenic regulatory factors. Maintenance of Pax7 deletion through continuous tamoxifen administration prevented regrowth of…

• MD
  Muscular Dystrophy Association
• NI
  National Institutes of Health
• CI
  Canadian Institutes of Health Research