Tissue Engineering And Nanotheranostics

b2815 Tissue Engineering and Nanotheranostics “9.61x6.69”

6 Tissue Engineering and Nanotheranostics

MyoD, which are expressed in myoblasts during fetal development.^18

Proliferation of the myoblasts continues during this stage as well as

differentiation into mononuclear myocytes. During this stage the

myoblasts MRFs expressed are Myf5, MyoD, and Mrf4.^18 However,

the mononuclear myocytes will express MyoD, Mrf4, and MyoG

MRFs.^18 The differentiation of myoblasts is the first step to muscle

fibril formation. During both the fetal and neonatal stage, mononu-

clear myocytes will group together to form multinuclear myofibrils

and myotubes, which group together to form muscles. The final

stage, adult myogenesis, involves adult progenitor cells that lie near

the basement membrane of adult myofibers. These progenitor cells

are quiescent stem cells that are termed SCs. These cells most com-

monly express the Pax7 marker along with Myf5, CD34, and

M-Cadherin.18,22 Recently, other receptors and transcription factors

have been identified to play a critical role in myogenesis; such as,

Fig. 1. Pr oteins expressed during the time course of myogenesis beginning with

embryonic progenitors. Proteins that are strongly expressed are bold, while proteins

that are weakly expressed are italicized.

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