Figure 4From: Dynamics of muscle fibre growth during postnatal mouse developmentSatellite cell number steadily decreases from P6, to reach the adult level by P21. Satellite cells were identified and counted on isolated Myf5nlacZ/+ and 3F-nlacZ-E myofibres and pooled at each age to give a mean ± SEM (a). The number of satellite cells per myofibre decreased by 0.66 satellite cells per day (R2 = 0.98) to reach the adult level by P21, when it remained unchanged until 10 months, our oldest age analysed. The same data with satellite cells expressed as a percentage of total myofibre nuclei (myonuclei plus satellite cells) (b). Due to the rapidly increasing myonuclear number, there is an exaggerated fall from P6 until P21. Data shown are mean ± SEM (n > 30 myofibres from at least 6 mice at P7, P14, P21 and P56, and at least 2 mice per age at all other stages).Back to article page