Thursday, November 15, 2007

Myostatin Man

One of my receptionists at work is dog-crazy and breeds whippets. Recently i came across an amazing photo of a so-called "Bully" Whippet- the Schwarzenegger of Whippets!
This dog is homozygous for a loss-of-function mutation in it's myostatin gene. Heterozygote whippets are faster runners than wild-type.
Belgian Blue cattle have been bred to have a similar genetic mutation. These "double muscled" cows produce 20% more meat but are so bulky they need to be delivered by caesarian!
The absence of myostatin in laboratory mice reduces the severity of obesity and diabetes , as well as helping muscle strength in the mouse model of Duchenne muscular dystrophy. (There is currently a trial testing a monoclonal antibody to myostatin in patients who have a form of muscular dystrophy known as fascio-scapulo-humeral dystrophy).
There have been several cases of myostatin mutations in humans including a case report in NEJM in 2004 of a baby boy born with enlarged muscles, and stimulus induced myoclonus (muscle twitching). The latter settled in 2 months, and other than being incredibly strong and 'muscly' is otherwise well with no cardiac dysfunction. Interestingly, his mother was a professional athlete, and his pedigree contains a number of relatives with exceptional strength. I suppose they could buy him a bully whippet for christmas.
I wonder if the presence of a myostatin mutation invalidates the mother's athletic achievements?


  1. In case you didn't notice, that Belgin Blue ain't no COW...

    Thats a lot of BULL!!!

  2. Yes- however, the 'love muscle' does not actually contain muscle.

  3. Anonymous8:00 AM

    I must say, to dispel the story that you have posted on your blog that not all Belgian blue calves must be delivered cesarean. I breed Belgian Blue cattle and I have never had to deliver one that way. We have selectively bred the females to have larger pelvises to handle the load that a full blood calf is.


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