Pax7, a transcription factor, is of great significance in multiple biological processes. It is a key regulator in myogenesis, with a major role in post-natal growth and muscle regeneration in adults, while its orthologue Pax3 predominates during early skeletal muscle formation in the embryo [4]. Pax7-positive satellite cells are crucial for skeletal muscle's regenerative capabilities as they donate nuclei to regenerating multinucleated myofibers [1].

In human skeletal muscle, an acute bout of exercise impacts Pax7+ satellite cells. Resistance exercise leads to a large increase in Pax7+ cell content in skeletal muscles 24 h post-exercise, with cells increasing to ~50% above pre-exercise level 24-72 h after resistance exercise. In the subgroup analysis of age, adults over 50 years show a large effect of exercise on increasing Pax7+ cells in exercised muscle, while younger adults show a medium effect [1]. Also, human skeletal muscle organoids can generate sustainable uncommitted PAX7 myogenic progenitors, which are equivalent to those from the second trimester of human gestation and can regenerate muscle when transplanted into adult mice [2].

In conclusion, Pax7 is vital for myogenesis, especially in post-natal muscle growth and regeneration. Research on Pax7, such as through exercise-related studies and organoid models, helps understand its role in muscle development and repair, providing potential insights for muscle-related diseases like muscular dystrophy where Pax7 may be a key for myogenesis modulation [3].