MyoD and Myf5 are considered primary MRFs and play a crucial role in the early stages of muscle development. They are involved in the determination of myoblasts, the precursor cells that give rise to muscle tissue. MyoD is known for its ability to convert non-muscle cells into muscle cells, a process known as myogenic conversion. Myf5, on the other hand, is critical for the initial formation of myoblasts during embryogenesis.
