The myogenic regulatory factors are necessary for the determination and terminal differentiation of skeletal muscle. Gene targeting experiments have demonstrated that MyoD and Myf5 are important for myogenic determination whereas myogenin and MRF4 are important for terminal differentiation and lineage maintenance. During development, all trunk skeletal muscle is derived from the somite. Two spa...

Developing human muscle contains inter-myofibre progenitors expressing Bmp-receptor 1a (Bmpr1a) and Myf5 that respond to stimulation with Bmp4. Here we ablate Bmpr1a in Myf5- and MyoD-expressing cells in vivo. Mutant mice reveal increased intramuscular fat and reduced myofibre size in selected muscles, or following muscle injury. Myo-endothelial progenitors are the most affected cell type: clon...

Epigenetic mechanisms, such as histone modifications and DNA methylation, have been shown to play a key role in the regulation of gene transcription. Results of recent studies indicate that a novel "bivalent" chromatin structure marks key developmental genes in embryonic stem cells (ESCs), wherein a number of untranscribed lineage-control genes, such as Sox1, Nkx2-2, Msx1, Irx3, and Pax3, are e...

Genetic regulatory networks governing skeletal myogenesis in the body are well understood, yet their hierarchical relationships in the head remain unresolved. We show that either Myf5 or Mrf4 is necessary for initiating extraocular myogenesis. Whereas Mrf4 is dispensable for pharyngeal muscle progenitor fate, Tbx1 and Myf5 act synergistically for governing myogenesis in this location. As in the...

Pax genes have important roles in the regulation of stem cell behavior, leading to tissue differentiation. In the case of skeletal muscle, Pax3 and Pax7 perform this function both during development and on regeneration in the adult. The myogenic determination gene Myf5 is directly activated by Pax3, leading to the formation of skeletal muscle. Fgfr4 is also a direct Pax3 target and Sprouty1, wh...

The Rho family GTP-binding proteins play a critical role in a variety of cytoskeleton-dependent cell functions. In this study, we examined the role of Rho family G proteins in muscle differentiation. Dominant negative forms of Rho family proteins and RhoGDI, a GDP dissociation inhibitor, suppressed transcription of muscle-specific genes, while mutationally activated forms of Rho family proteins...

Abstract Understanding the myogenic and self-renewal capability of satellite cells under heat stress (HS) is fundamental to coping with global warming in beef cattle industry. Study objectives were determine transcriptomic changes proliferation bovine (BSCs) moderate versus acute levels HS exposure times. Satellite isolated from four three-month-old Holstein calves (semitendinosus) cultured 10%...

Selective breeding has led to diverging phenotypic evolution in layer and broiler chickens through genomic and epigenetic modifications. Here we show that in ovo environmental manipulation differentially influences embryonic limb muscle phenotype in these two breeds. We demonstrate that raising incubation temperature from 37.5 to 38.5°C between embryonic days (ED) 4 and 7 increased motility and...

Rhabdomyosarcomas (RMS) bear a morphological resemblance to developing striated muscle. It has been reported that two histologically distinct subtypes of RMS, embryonal and alveolar, behave differently in many clinical aspects, such as age distribution, primary site, and prognosis. We have investigated the expression of various genes, which are preferentially expressed in normal muscle tissue o...

Mature adipocytes are postmitotic (1), and therefore development of adipocytes requires the proliferation and differentiation of progenitor cells into mature adipocytes. The identity of adipose precursor cells and the molecular mechanisms that control their proliferation and differentiation are only partially understood. Brown adipose tissue (BAT) is specialized for energy expenditure through a...