Muscle Biology: Muscle Cell Line

There are many steps an adult stem cell must take before it differentiates into a muscle fiber.  Here is a simplified guide to the muscle cell line. 

Stem Cell - a cell that eventually grows into a tissue or organ over an extended period of time.  During a stem cell's growth it will start to specify to its taget tissue or organ which is known as a progenitor cell. Before the stem cell becomes a progenitor cell it will activate a specific gene that determines how the cell will differentiate.  Specifically, for a cell that will grow into a muscle fiber the myogenic regulatory factors (MRFs) are activated. Myf5 as well as Mrf4 (Myf6) or MyoD (Myf3) gene are all MRFs that lead to muscle identity when threshold levels of these transcripton factors are reached.  Once, a progenitor cell reaches muscles identity it is considered a myoblast (precursor to a muscle fiber). The myoblast will eventually differeniate into a muscle fiber.

Myoblast Used in Research

C2C12 is a muscle cell found in mice.  In studies examining muscle biology in vitro it is a standard non-differianted muscle cell used in cell culture.  Muscle biologists will grow these cells to perform all sorts of experiments to better understand skeletal muscle growth.

Reference:

Tajbakhsh, S.  (2005).  Skeletal muscle stem and progenitor cells: reconciling genetics and lineage.     Experimental Cell Research, 306, 364-372.