[how mature muscle cells are made]
Muscle fibers generally form the fusion of myoblasts into multi-nucleated fibers called myotubes.
- In early development, myoblasts can either proliferate, or differentiate into a myotube.
- once differentiated, myoblasts align
- cells fuse - presence of calcium ions is critical, involves recruitment of actin to the plasma membrane, followed by close apposition and creation of a pore that subsequently rapidly widens.
Stages and associated genetic factors
- Delamination –> PAX3, c-Met
- Migration –> c-met/HGF, LBX1
- Proliferation –> PAX3, c-Met, Mox2, MSX1, Six1/4, Myf5, MyoD
- Determination –>Myf5 and MyoD
- Differentiation –> Myogenin, MCF2, Six1/4, MyoD, Myf6
- Specific Muscle Formation –> Lbx1, Meox2
- Satellite Cells –> PAX7