- Myogenesis
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Myogenesis is the formation of muscular tissue, in particular during embryonic development.
Muscle fibers form from the fusion of myoblasts into multi-nucleated fibers (called myotubes). In the early development of an embryo these myoblasts will proliferate if enough fibroblast growth factor is present. When the FGF runs out, the myoblasts cease division and secrete fibronectin onto their extracellular matrix.
The second stage involves the alignment of the myoblasts into the myotubes. The identity of the myoblasts in this stage is not crucial. Studies have shown that even rat and chick myoblasts have aligned. [1]
The third stage is the actual cell fusion itself. In this stage, calcium ions are critical for development. Fusion is mediated by a set of metalloproteinases called meltrins. Myocyte Enhance Factors (MEFs) promote myogenesis. Serum response factor (SRF) plays a central role during myogenesis, being required for the expression of striated alpha-actin genes[2]. Expression of skeletal alpha-actin is also regulated by the Androgen Receptor; steroids can thereby regulate myogenesis [3].
References
- ^ YAFFE D, FELDMAN M. THE FORMATION OF HYBRID MULTINUCLEATED MUSCLE FIBERS FROM MYOBLASTS OF DIFFERENT GENETIC ORIGIN.
- ^ Wei L, Zhou W, Croissant JD, Johansen FE, Prywes R, Balasubramanyam A, Schwartz RJ.RhoA signaling via serum response factor plays an obligatory role in myogenic differentiation.J Biol Chem. 1998 Nov 13;273(46):30287-94.PMID: 9804789
- ^ Vlahopoulos S, Zimmer WE, Jenster G, Belaguli NS, Balk SP, Brinkmann AO, Lanz RB, Zoumpourlis VC, Schwartz RJ.Recruitment of the androgen receptor via serum response factor facilitates expression of a myogenic gene.J Biol Chem. 2005 Mar 4;280(9):7786-92. Epub 2004 Dec 28.PMID: 15623502
External links
Musculoskeletal physiology: Muscular physiology Exertion Other MyogenesisCategories:- Developmental biology stubs
- Developmental biology
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