July 25, 2007
Dog Muscle Mutation Useful For Humans?
If this mutation gets inserted into some human muscle cells would it make the human recipients more muscular?
Double muscling is a trait previously described in several mammalian species including cattle and sheep and is caused by mutations in the myostatin (MSTN) gene (previously referred to as GDF8). Here we describe a new mutation in MSTN found in the whippet dog breed that results in a double-muscled phenotype known as the “bully” whippet. Individuals with this phenotype carry two copies of a two-base-pair deletion in the third exon of MSTN leading to a premature stop codon at amino acid 313. Individuals carrying only one copy of the mutation are, on average, more muscular than wild-type individuals (p = 7.43 × 10−6; Kruskal-Wallis Test) and are significantly faster than individuals carrying the wild-type genotype in competitive racing events (Kendall's nonparametric measure, τ = 0.3619; p ≈ 0.00028). These results highlight the utility of performance-enhancing polymorphisms, marking the first time a mutation in MSTN has been quantitatively linked to increased athletic performance.
What I thought as I read about this dog muscle gene deletion mutation: Future genetic engineers looking to enhance human function will search through animal genetic variations and choose ones that provide desired enhancements. Take this myostatin mutation for example. Humans also have myostatin genes. A similar mutation introduced into human myostatin might yield the same enhancement to human musculature.
Other species of mammals are adapted to a large variety of conditions and ecological niches. They have many of the same genes but in different variations. We are going to find variations such as the one above that does something special for other species. These variations and their functional purposes are going to serve as a grab bag of pre-tested genetic variations that can allow humans to endow themselves with a large variety of special abilities that humans now lack.
One big problem with this kind of mutation is that the dog suffered from, often crippling, muscle cramps.
Surely a better goal would be for denser muscles rather than more of the same. Chimps have much denser muscles than humans and I think it would be better to give humans this than merely doubling up. More aesthetic too.
"The so-called myostatin blockade has generated tremendous interest in the bodybuilding community. Some nutritional supplements claim to block myostatin, but researchers have said the claims are not scientifically valid." - from the above ctv.ca article.
It seems fair to expect that products acting on myostatin will become available within a couple of decades, perhaps first in non-FDA approved products for the bodybuilding community. Could be an instant cure (relatively) for many who struggle with obesity.
Chimpanzee muscles work around five to seven times more efficiently than ours possibly due to a difference in the myosin gene called MYH16.
One issue though is that you likely also need much denser bones to support the extra strength in the muscles. This will make humans unable to swim, just like chimps. So, good for Barry Bonds, but not so much for Michael Phelps.
These variations and their functional purposes are going to serve as a grab bag of pre-tested genetic variations that can allow humans to endow themselves with a large variety of special abilities that humans now lack.
I hadn't thought much about inter-species borrowings for human beings, nor at all of their being somewhat pre-tested. Thanks.
I wonder if chimps are unable to swim due to their really only slightly higher density, (Which certainly ought to be compensated by their higher strength!) or some other factor? A quick search suggests that chimpanzees lack the ability, so essential to swimming, to consciously control their breathing. They can't hold their breath!
Great reference to that MYH16 gene. We are going to be able to compare all the genetic variations of muscle-related genes across all species. Likely we will find some species which have muscle function that is superior to our own for a large variety of purposes. Also, some species will have improvements in some areas of muscle performance without any downsides that have to be traded off against.
One problem with using genes from other species is that most species are not as long-lasting as humans (and I really really wish I could change this state of affairs for dogs in particular). I'm especially interested in genetic variations that make components last longer. Can we combine muscle-related genes from multiple species to come up with higher performing, more efficient, and longer lasting muscles?
Mthson, Stephen Gordon,
I had it in the back of my mind to do an update to the post and link to some of the genetic variations for greater musculature already found in rare humans. Thanks for digging up those links.
Strong muscles against weak bones: Obviously we need to find a way to genetically engineer a better biological process for making much stronger bone.
I think that some insects have the strongest muscles, moluscs have the greatest musclular endurance, and birds have the combination of strength and speed that seems most optimal for an enhanced human (though robotics will probably enable better still eventually).
One cause for concern regarding chimp muscles is that natural selection has already shown that in our ancestral environment, hominids with our type of muscle out competed those with ape style muscles.
Anyway, is MYH16 relevant to arm strength, or only active in the jaw?