[ mī′ə-tōōb′ ] Save This Word! n. A developing skeletal muscle fiber with a tubular appearance.

What are myotubes?

[ mī′ə-tōōb′ ] Save This Word! n. A developing skeletal muscle fiber with a tubular appearance.

What is a myoblast?

Definition of myoblast : an undifferentiated cell capable of giving rise to muscle cells.

How are myoblasts formed?

Chapter Review. Muscle tissue arises from embryonic mesoderm. Somites give rise to myoblasts and fuse to form a myotube. The nucleus of each contributing myoblast remains intact in the mature skeletal muscle cell, resulting in a mature, multinucleate cell.

What happens after the fusion of myoblasts?

Muscle fibers generally form through the fusion of precursor myoblasts into multinucleated fibers called myotubes. In the early development of an embryo, myoblasts can either proliferate, or differentiate into a myotube.

What happens in myogenesis?

Myogenesis is the formation of muscular tissue, particularly during embryonic development. Muscle fibers form from the fusion of myoblasts into multi-nucleated fibers called myotubes. In early embryonic development, these myoblasts proliferate if enough fibroblast growth factor (FGF) is present.

How are myotubes made?

Control of Muscle Development and Differentiation Primary myotubes are developed from embryonic myoblasts and can differentiate into both slow (type I) and fast fiber types (type II). This differentiation occurs before the motor nerve axons have contacted the newly formed muscle.

What do myoblast cells do?

Myoblasts, the mononucleate precursor cells of skeletal muscle, can differentiate to form multinucleated muscle fibers capable of muscle contraction.

What does a Myograph do?

A myograph is any device used to measure the force produced by a muscle when under contraction. Such a device is commonly used in myography, the study of the velocity and intensity of muscular contraction.

Are myoblasts multinucleated?

Experiments with chimeric mice and cultured myoblasts showed conclusively that these cells align together and fuse to form the multinucleated myotubes characteristic of muscle tissue.

Are myoblasts multipotent?

Skeletal myoblasts are resistant to ischemia, one of the main obstacles to the proper function of stem cells in the infarcted myocardium [115]. They are multipotential and are capable of forming osteocytes, adipocytes, and myocytes in vitro [116].

Do myoblasts divide?

Figure 14.10. Conversion of myoblasts into muscles in culture. (A) Determination of myotome cells by paracrine factors. (B) Committed myoblasts divide in the presence of growth factors (primarily FGFs), but show no obvious muscle-specific proteins.

What do myofibrils do?

The main function of myofibrils is to perform muscle contraction. There is an incomplete overlap between the thin and the thick filaments when the muscle is at rest.

How does myogenesis occur in skeletal muscle?

Myogenesis in adult skeletal muscle (regeneration after injury) depends on the activation of muscle-specific stem cells called satellite cells that have the potential to differentiate into new fibers [32]. This type of myogenesis occurs when mature muscle is injured and satellite cells are activated,…

How does myogenesis induce cell commitment?

Myogenesis is an excellent paradigm for examining how cell fate is induced. It has long been hypothesized that prior to the acquisition of a differentiated phenotype, the process of cell commitment relies on the expression of a small number “master” regulatory or master “switch” genes.

What drives satellite cell commitment and self-renewal during myogenesis?

Similar to embryonic development, a wide variety of signaling molecules in the niche control the fate of satellite cells in mature muscle ( Bentzinger et al. 2010 ). In analogy to developmental processes, Wnt proteins have emerged as crucial regulators of satellite cell commitment and self-renewal during postnatal myogenesis.

Is temporal switch necessary for normal myogenesis in muscle stem cells?

A temporal switch from Notch to Wnt signaling in muscle stem cells is necessary for normal adult myogenesis. Cell Stem Cell 2: 50–59. Brand-Saberi B, Krenn V, Grim M, Christ B. 1993.