Muscle Biology: Terminology

Here is my list of important terms in the field of muscle biolgy.  This post will be constantly updated as I learn more definitions through research.

Akt/mTOR pathway - an intracellular signaling pathway that primarily leads to an increase in protein synthesis

Canonical pathway - standard pathway once a ligand binds to a receptor

Frizzled (Fzd) receptors - a family of seven-pass transmembrane receptors cotaining a rich-cysteine domain for Wnt ligands

Insulin Growth-like Factors (IGFs) - a group of proteins that have similiar characteristics to insulin.  When IGF binds to its receptor a cascade of intracellular signaling molecules leads to an increase in protein synthesis 

Muscle atrophy - a decrease in muscle mass

Muscle dystrophy - a group of genetic muscle wasting diseases

Muscle hyperplasia - physiological proliferation increase in number of cells

Muscle hypertrophy - an increase in myofiber size through increased sarcoplasmic volume and/or increased contractile proteins

Myoblasts - skeletal muscle precursor cells that have the potentital to differentiate into myocytes

Myocyte - a muscle cell

Myofiber - multinucleate cell composed of numerous myofibrils

Myogenesis - the generation of new muscle tissue

Myogenic regulatory factors (MRFs)

Myotube - a developing skeletal muscle fiber

Sarcolemma - membrane of a muscle cell

Sarcopenia - loss of muscle mass due to ageing

Satellite cell - adult stem cells of skeletal muscle

Somite -  a segmental mass of the mesoderm in the embryo developing into muscles

Wnt - a family of signaling proteins that typically bind to Fzd receptors

Reference:

Maltzahn, J., Chang, N. C., Bentzinger, C. F., & Rudnicki, M. A. (2012). Wnt Signaling in myogenesis. Trends in Cell Biology 

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.

Welcome to The Muscle Biology Blog

Hello muscle biology enthusiasts.  I am a a first semester doctoral student in Exercise Science focusing in cell and molecular biolgy and my primary research interest is skeletal muscle hypertrophy.  Over the next four years I plan to  keep detail reports of serveral lab procedures, summaries of new research in skeletal muscle (both basic and applied), and teach muscle biology terminology.  This will all be in line with mission statement below,

Mission Statement: To improve the understanding of muscle biology, physiology, and nutrition primarily in skeletal muscle hypertrophy.



I will start will with the following topics of interests to me:

- New Research
- Applied Research
- Intro to Muscle Bio
- Bodybuilding Tips
- The Muscle Bio Lab


If you are a subscriber to this blog and have any topics you would like to see just let me know.  Thanks for your time and enjoy the information.