Just recently, a fairly indepth thread developed here on GetBig about the super muscled German five-year-old who has been identified as being almost completely myostatin deficient. A couple of the guys asked me to explain the sciencey bit in layman's terms, so I did, and added in a few of the unsubstantiated rumours for titillation purposes.
My big epic post is copied below, enjoy:
(the original thread is:http://www.getbig.com/boards/index.php?topic=40799.0 )
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Okay, okay...
Here's the backroom gossip on myostatin:
Background...
For those who don't have any science edu-macation (considering how it's taught in schools these days I wouldn't be surprised if that's most of those reading), we'll start with the basics of genetics. Feel free to skip ahead if you already know this, for the rest of you I'll try to adhere to the tenet by being both witty and brief.
The human body is built (mostly) of proteins, these proteins are manufactured within the individual cells. The proteins are assembled from amino acids, think of little molecular letters being strung together to make words. There are only four DNA bases (rudimentary amino acids), they are adenine (A), thymine (T), guanine (G) and cytosine (C). All human DNA is composed of these four bases. That's why that Ethan Hawk sci-fi movie about genetic engineering was called Gattaca.
Get it?
Gattaca = G A T T A C A G A T T A C A guanine adenine thymine thymine adenine cytosine adenine ...it's a gene sequence!!
DNA is a two stranded molecule complex, a string of ATCG's linked to another string of ATCG's and held together by a big ribose sugar.
For example, a string of DNA can be represented by just the data in the strands
A-T
C-G
G-C
C-G
T-A
A-T
C-G
G-C
T-A
Adenine always bonds to thymine (A-T and T-A), cytosine always bonds to guanine (C-G and G-C) so if the strand splits...
A- -T
C- -G
G- -C
C- -G
T- -A
A- -T
C- -G
G- -C
T- -A
...then free floating bases (un-paired adenine, thymine, cytosine and guanine molecules) bond up to the strands...
A-T -T
C- C-G
G- -C
C-G -G
T- -A
A- A-T
C- -G
G-C -C
T- -A
...pretty soon you get...
A-T A-T
C-G C-G
G-C G-C
C-G C-G
T-A T-A
A-T A-T
C-G C-G
G-C G-C
T-A T-A
...TWO PERFECT COPIES OF THE ORIGINAL STRAND.
This is basically what happens in sexual reproduction. You get half of your Dad's chromosomes (bundles of multi-billion digit strands), and half of your Mum's chromosomes. The 23 chromosomes from your Dad team up with their opposite numbers from your Mum to form 23 chromosome pairs (46 chromosomes total).
It's the pairs that then set about producing all the relevant proteins, (and organs, limbs, bones etc) making a new individual.
For example, one of the pairs is responsible for gender. Your Mum has an XX pair, (two X chromosomes, so called because they look like... well... an X), so she'll pass on either one of these X chromosomes.
So you get an X sex chromosome from your Mum.
Your Dad has an XY pair for a sex chromosome (guess what the Y chromosme looks like under the microscope! Biologists have NO sense of humour) so he'll pass on either an X or a Y sex chromosome. (when his chromosome pairs are split up to make 23 chromosome cells: sperm)
Hence the Baby gets an X from the Mum and either an X or a Y from the Dad.
An XX sex chromosome pair (like the mothers) will produce a female baby, an XY pair (like the fathers) will produce a male baby.
However, and this is where things start to get interesting. The splitting of the chromosme pairs isn't always perfect... somethimes deletions or double ups can happen. With the sex chromosome you could possibly get:
XX normal healthy female
XY normal healthy male
X a slightly less fertile female with male personality traits
XYY hyper male, higher testosterone and very aggressive, three times more likely to commit murder and disproportionately abundant in the populations of maximum security prisons.
XYYY super male, supposedly taller, larger, more intelligent men with an increased statistical tendency to be paedophiles.
XXYY very little information available, but much more likely to be born with ambiguous genitalia or even hemaphroditic
XXXYY sometimes male, sometimes female, sometimes intersex but usually homosexual or transexual. ...interesting eh?
THE MYOSTATIN BIT
In the early nineties genetics labs around the world started picking a gene (a string of three bases such as ACG or GAT) at random and simply cutting it out. But seeing as 90% of DNA in most animals (including humans) is simply inactive junk... the experiments seldom did anything unusual in the altered animals. After all, they were only changing one-hundred-millionth of one strand in one chromosome in one of the chromosome pairs.
That is until until someone produced wasps with extra legs growing out of their eyeballs.
The first Hocks gene had been found!
Out of the 5 billion-odd genes in the human genome, only about 20,000 are active. How could only 20,000 genes describe all the blueprints for something as complex as a human being and all the biochemical systems it involves?
The answer: some of the genes (Hock's genes) act as master control switches activating and more importantly de-activating other genes and controling how the active genes interact with the inactive junk DNA.
Hence the same genes that grow gills in fish can be modultated by the affect of Hocks genes to produce lungs in human beings. Amazing eh??
One of these master genes (called Myostatin) controls the distribution of muscle tissue. When scientists removed the gene from mice they expected to produce mice with absolutely NO muscle tisue. But instead of Skeletor mice they got He-man mice, three times the weight of a normal mouse, 5% bodyfat instead of 20% and rippling with muscles.
It seems the foetus doesn't just grow muscle tissue when it's developing, it has to be told when to STOP producing muscle.
But here is the problem, no one is quite sure how this gene is expressed.
-Does it set other genes into effect during foetal development. Does it tell the foetus when there are enough muscle cells in the meso-layer thereby producing individuals with increased (but fixed) numbers of muscle cells when it's absent?
-does it tell muscle cells when to stop splitting into more muscle cells? A process known as hyperplasia (it doesn't seem to happen in humans, normal humans).
-does it produce an intra-cellular hormone that regulates/halts muscle growth?
-does it desensitise hormone receptors on muscle cells? No myostatin and the muscles become more and more sensitive to the effects of GH, IGF-1 or insulin?
As you can see it all gets very complicated very quickly...
We do have a few hints:
*the He-man mice were odd in other ways. They had a poor metabolic response to exercise and were so timid that normal mice in the same cage literally ATE THEM ALIVE!! Meaning the absence of myostatin could have neurological effects.
*no major internal abnormalities/pathologies have been noted (nothing that couldn't be explained by the increase in bodyweight) raising doubts that myostatin only has effects within the womb, if it did then we could expect some developmental disorders.
(for example: Proteus syndrome, a gene halting skeletal formation is damaged/missing and those double recessive for the gene are characterised by extra long big toes. However every time a Proteus sufferer bruises themselves, the bruised muscle calcifies to form a bone because the skeletal formation system has not been turned off.)
*another Hocks gene removed from mice produced abnormally fat mice with huge appetites. This gene was called Leptin and was hailed as the Holy Grail of obesity research when it turned out to be a hither-to-unknown hormone. No leptin equals fat ass mice, extra leptin lowered the mice's appetites and bodyfat levels. Unfortunately it didn't work in adult humans till your bodyfat levels were already under 5%.
I would hazard a guess that myostatin turns out to be the same deal as leptin: it's biggest effects will happen in the womb and people taking anti-myostatin will have pumped muscles that are two weak to be trained, or will notice no difference at all.
Either way, Dorian-abol is probably never going to happen.
Now here is where we enter the Twillight Zone:
According to reliable reports this German Myostatin deficient five-year-old (both his parents are mono-recessive for a damaged version of the gene) is perfectly normal except for his muscle size.
BUT the same reports are at pains to withold the identity of the family, and the authors gloss over the fact that the boy is about EIGHT TIMES STRONGER than children his own age pointing out that this ratio will probably decrease with age till he is only 150% as strong as other adults when fully grown. He is tall for his age but nothing out of the ordinary.
The family involved have an ironclad legal arrangement with the doctor who is doing the research and will never be identified without their consent. ALL the details of of the published research must be cleared with the family first. NO OTHER medical experts have examined the boy.
The boys school hired a helper to patrol the schoolyard, (follow monster boy around without getting close enough tomake it obvious) after the myostatin kid picked up and threw one of his class mates.
***** EVERYTHING WRITTEN BELOW IS COMPLETELY UNSUBSTANTIATED *****
The RUMOUR (and this is only a rumour) in the genetics community is that all this excessive secrecy is warranted because the there is no sign of the boys growth spurt slowing down. Apparently there is every chance that the estimated 220-240 lbs adult weight is a lie.
A few geneticists interested in the case have reported that should his growth pattern continue (there's no way to tell if it's a growth spurt or the normal growth pattern for someone with his condition) he will probably weigh 450-600 lbs with 5-8 % bodyfat AT EIGHT FEET TALL when fully grown. One geneticist claimed an adult size of 200 lbs at five foot is more likely, while another disputed the eight foot claim saying seven foot was more realistic... seven foot AND 800-1,100 lbs!!!
But all of this is only speculation, it's the conspiracy theories that are more interesting.
The child's face has never been shown in a photo, not even in the photos taken of him as a baby. Neither have his arms... leading to the claim that the child has splayed legs, an unusual pelvis structure, enlarged joints, thick bones, a bell shaped rib cage, an enlarged jaw/dental structure, robust features (deep-set eyes and a heavy brow ridge) along with an unusual forearm to upper arm ratio. Does any of this ring a bell with anyone... ever heard a description of a Neanderthal??
If a four year-old can hold 15lb dumbbells at arms length in a crucifix position for 10 minutes... is it so far beyond the realms of possibility that he's a throwback... missing the gene that separated us from proto-European cavemen 30,000 years ago??
But then again, sparse evidence often breeds wild theories...
It has been hinted that the German government has already made arrangements to put the family into hiding should the need arise. Sound planning to some, but to the adherents of conspiracy theory it lends credence to the wildest claims: that the boy had his whole body electrolysed to remove excessive body hair and has distinctly simian features. Big hands, long arms and REALLY, REALLY BIG FEET!!! INCLUDING A HINGED FOOT WITH A META-TARSAL BREAK!!
Maybe he'd be more at home in the forests of Northern California.
Of course that is just totally crazy... isn't it??
Isn't it??
The Luke
PS- all you guys owe me five bucks.
