(formerly known as '''
Growth Differentiation Factor 8''') is a
Growth Factor that limits
Muscle tissue growth, i.e. higher concentrations of myostatin in the body may cause the individual to have less developed muscles.
The myostatin
Protein is produced primarily in skeletal muscle
Cells , circulates in the
Blood and acts on muscle tissue, apparently by slowing down the development of muscle
Stem Cell s. The precise mechanism remains unknown. Its functions in non-mammalian vertebrates appear to be somewhat conserved as muscle-specific actions have been demonstrated in birds. However, it is produced in many different fish tissues, suggesting that it may regulate more than just muscle mass in these vertebrates.
Myostatin and the associated 2006;190(3):879-88. PMID 17003288. This further suggests that the physiological and developmental aspects of myostatin biology may be quite different from that in mammals.
Lee and others found in 1997 that the double muscled cattle breeds ''
Belgian Blue '' and ''Piedmontese'' have defective myostatin genes; these strains have been produced through breeding. [http://www.builtreport.com/bovine.html Photos of double muscled Myostatin inhibited Belgian Blue Bulls]
12
In
2004 , a
German boy was diagnosed with a mutation in both copies of the myostatin-producing gene, making him considerably stronger than his peers. His mother, a former sprinter, has a mutation in one copy of the gene.
cevgenetica: Gene Mutation Makes German Boy Extra Strong Muscle Baby Gina Kolota:
A Very Muscular Baby Offers Hope Against Diseases , The New York Times, June 24, 2004. (Requires login)
Genetic mutation turns tot into superboy Muscle Boy One Strong Tyke: Gene mutation in muscular boy may hold disease clues 3 More recently, an American boy born 2005 was diagnosed with the same condition.
"Rare condition gives toddler super strength"
Myostatin is a member of the
TGF Beta Superfamily of proteins.
Human Myostatin consists of two identical subunits, each consisting of 110
Amino Acid residues. Its total
Molecular Weight is 25.0 k
Da . It can be produced in genetically engineered
E. Coli or eukaryotic cells and the recombinant protein from both sources is commercially available. However, due to the unique manner by which the mature protein is processed, there is considerable doubt as to the effectiveness of myostatin generated in E. coli.
A 2007 NIH study in PLOS Genetics found a significant relationship in
Whippet s between a myostatin mutation and racing performance. Whippets that were heterozygous for a 2 base pair deletion in myostatin were significantly over-represented in the top racing classes. Whippets with a homozygous deletion were apparently less able runners although their overall appearance was significantly more muscular. The 2 base pair mutation resulted in a truncated myostatin mRNA, likely resulting in an inactive form of myostatin.
Interestingly, whippets with the homozygous deletion also had an unusual body shape, with a broader head, pronounced overbite, and shorter legs. These whippets have also been called "bully whippets" by the breeding community due to their size, but not their temperament.
This particular mutation was not found in other muscular dog breeds such as
Boxers and
Mastiff s, nor was it found in other slight hounds such as
Greyhound s,
Italian Greyhound s, or
Afghan Hound s. The authors of the study suggest that myostatin mutation may not be desirable in greyhounds, the whippets' nearest relative, because greyhound racing requires more significant endurance due to the longer races (900 meters for greyhounds vs. 300 meters for whippets).
Further research into myostatin and the myostatin gene may lead to therapies for , researchers at the
University Of Pennsylvania showed that
Monoclonal Antibody specific to myostatin improves the condition of mice with muscular dystrophy, presumably by blocking myostatin's action.
In
2005 , Lee showed that a two-week treatment of normal mice with soluble ''
Activin Type IIB Receptor '', a molecule that is normally attached to cells and binds to myostatin, leads to a significantly increased muscle mass (up to 60%).Lee SJ ''et al.'' ''
Regulation of muscle growth by multiple ligands signaling through activin type II receptors. '' Proc Natl Acad Sci U S A. Dec 5, 2005. PMID 16330774 It is thought that binding of myostatin to the soluble activin receptor prevents it from interacting with the cell-bound receptors.
It remains unclear whether long term treatment of muscular dystropy with myostatin inhibitors is beneficial: the depletion of muscle
Stem Cell s could worsen the disease later on.
and recently underwent testing however the results have not yet been made public.FDA's record on the MYO-029 Myostatin Inhibor Trial is
NCT00104078 Medical News Today press article about the
Myostatin Inhibtor trial http://www.mda.org/research/061204myo_029_nov06.html Some athletes, eager to get their hands on such drugs, turn to the internet, where fake "myostatin blockers" are being sold.
Johns Hopkins University owns the
Patent s on myostatin.
