Pax7-flox Mouse

Pax7, a transcription factor, is a key regulator in myogenesis [3,4,6]. It is commonly used as an indicator in muscle research [3]. Pax7 is closely associated with the function of muscle stem cells, especially satellite cells, which are crucial for skeletal muscle maintenance, repair, and regeneration [1,2,3,4,5,6,8]. Pax7 may also be involved in the self-renewal of spermatogonial stem cells in dairy goats [7]. Pax7 reporter mouse models have been developed to study satellite cell-mediated events [8].

In human skeletal muscle, an acute bout of exercise affects Pax7+ satellite cells. Resistance exercise leads to a large increase in Pax7+ cell content in skeletal muscles 24 h after exercise, with cells increasing to ~50% above pre-exercise level 24-72 h after resistance exercise. In adults over 50 years old, resistance exercise has a large effect on increasing Pax7+ cells in exercised muscle, while in younger adults, it has a medium effect [1]. In vitro, human skeletal muscle organoids can generate sustainable uncommitted PAX7 myogenic progenitors, which can regenerate muscle when transplanted into adult mice [2].

In conclusion, Pax7 is essential for myogenesis, especially in post-natal growth, muscle regeneration, and the function of satellite cells. Research on Pax7, including through the use of mouse models, provides insights into muscle-related processes and may potentially contribute to understanding and treating muscle-related disorders such as muscular dystrophies [3].