growth/size/body
• body weight is increased in adult mice but not in 8-week-old mice
• the increase in mass of skeletal muscle correlates with the increase in weight
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muscle
• skeletal muscles show an enlarged pool of adult muscle stem cells (satellite cells); muscle stem cells do not show a major change in the activation state under baseline conditions
• preparations of whole body skeletal muscle, tibialis anterior muscle, and soleus muscle show increased numbers of muscle stem cells
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• soleus muscle shows increased numbers of myonuclei, but unchanged weight or cross-sectional area of myofibers
• 8-month-old mice show increased number of both myonuclei and increased myofiber cross-sectional area, indicating hypertrophy of the myofibers
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• adults, but not 8-week-old mice, show an increase in skeletal muscle weight
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• increase in myofiber cross-sectional area of skeletal muscle, indicating skeletal muscle hypertrophy
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• skeletal muscles show an enlarged pool of adult muscle stem cells (satellite cells)
• however, no reduction in the heterochromatin is seen, indicating that the increased number of muscle stem cells is not due to loss of quiescence of muscle stem cells
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• small, but significant, increase in number of Pax7+/MyoD+ nuclei in tibialis anterior (TA) muscle, indicating an increased number of spontaneously activated muscle stem cells
• mice show no differences from wild-type mice in muscle regeneration following TA muscle damage by cardiotoxin injection, however when regeneration is completed, the same increases in muscle stem cell numbers, EdU-incorporating muscle stem cells, and myofiber size is seen as before the damage in regenerated muscle, indicating stimulation of muscle stem cell proliferation and skeletal muscle growth during regeneration
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• mice show a great increase in EdU+/Pax7+ muscle stem cells, indicating enhanced proliferation of muscle stem cell-derived myoblasts which eventually increases the number of quiescent muscle stem cells
• however after proliferation, these muscle stem cells return to a quiescent state
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cellular
• mice show a great increase in EdU+/Pax7+ muscle stem cells, indicating enhanced proliferation of muscle stem cell-derived myoblasts which eventually increases the number of quiescent muscle stem cells
• however after proliferation, these muscle stem cells return to a quiescent state
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