Researchers Create "Mighty Mouse" With Gene Tweak

cylonlover writes "He can't fly just yet, but a team of scientists have made a big step towards creating a real-life Mighty Mouse. By tweaking a gene that normally inhibits muscle growth the researchers created a batch of super-strong mice and worms. The scientists acted on a genome regulator — known as NCOR1 — and were able to change the activity of certain genes. In simpler English, the scientists shut off the thyroid hormone that keeps most mammals from turning into the Incredible Hulk. The result was a strain of mice with muscles that were twice as strong as normal."

Comments

Give to 1 area, ur taking from another

[Anonymous Coward]

I figure it this way: You give these mice that growth of musculature, something's going to take a beating (probably lifespan), because the body's designed to only grow so much in that area, there must be a reason, a LONG TERM REASON, why.

Re:Give to 1 area, ur taking from another

[Defenestrar]

Well it depends, if it is twice the muscle mass then you're right - something's probably gotta give. But the summary (and news article) states twice the muscle strength, and if that doesn't have a corresponding mass or metabolic burden (e.g. good resting efficiency) then there's no reason to automatically suspect such a biological cost.

Re:Give to 1 area, ur taking from another

[MikeyO]

I figure it this way: You give these mice that growth of musculature, something's going to take a beating (probably lifespan), because the body's designed to only grow so much in that area, there must be a reason, a LONG TERM REASON, why.

I reject the notion that mice were "designed" or that a mouses body is the way it is due to any reasoning.

Re:Give to 1 area, ur taking from another

[The Grim Reefer]

You give these mice that growth of musculature, something's going to take a beating

Yeah, any unaltered mice are going to take a beating for sure.

Re:Give to 1 area, ur taking from another

[somersault]

One meaning of the word reason is "explanation". We can explain why many genetic traits have been beneficial and helped a species to survive and propagate. He didn't say anything about "due to reason", he said "there must be a reason".

Re:Give to 1 area, ur taking from another

[tixxit]

But by that logic, leading a sedentary lifestyle will lead to long life. Everyone is different and some people put on muscle mass way faster than others, just from their natural genetics. Being able to put muscle on easier than average is far from a sure ticket to a heart attack.

Re:Give to 1 area, ur taking from another

[nedlohs]

"reason" wasn't the problematic term, "designed" was, as in "... the body's designed to ...".

It is not designed to do anything, because it isn't designed in the first place.

However, even the reason part is crap. "There must be a reason, a LONG TERM REASON" is just plain wrong.

Evolution makes no claims of optimal outcomes in the first place.

Maybe said mutation just never happened in the wild? Maybe the disadvantages it also produced are no longer disadvantages due to environmental changes or other genome changes? Maybe it doesn't actually give an advantage to survival or reproduction? Maybe is requires more energy input which is bad in the short term? Maybe there's one of a million other short term disadvantages that don't apply in a lab setting.

Assuming it must be bad is the antithesis of evolution - a theory in which the core concept is that such a change might be beneficial.

Re:Give to 1 area, ur taking from another

[ElectricTurtle]

Natural selection results in 'good enough' genetics. There isn't any reason why people couldn't have eyesight as good as predatory birds (though some diet changes would be needed), or hearing as good as bats, or olfactory senses as good as canines, etc. but the conditions under which we evolved did not include pressures that selected for senses beyond our current state. Our sense were not maximized, simply good enough for most to survive, and that is natural selection's ultimate standard.

Speciation is not about some 'ultimate lifeform' so much as it is about lifeforms that are best adapted to their niche and environment. Predatory birds need top eyesight to catch quick small prey on the ground. We don't need it because our prey was usually bigger, or stationary (being omnivores). By the same token mice might just not have needed more strength to survive. Furthermore, and more importantly, if environmental pressures were such that only stronger mice were surviving, you could damn near bet money that these sorts of genetic changes would occur naturally. In a model of punctuated equilibrium, you'll find that changes usually occur when they have to, not simply because they are 'objectively better' in some abstract sense that doesn't significantly impact survival rate in a given environmental condition.

Re:Give to 1 area, ur taking from another

[somersault]

Yep, though it's easy to let words like design and creature slip into this kind of thing even if you're not religious. What you're saying is repeated so often that I just would assume he already knows it, thougn I may be wrong of course. It's okay to point out common mistakes, but it's just as bad if you repeat the "truth" without thinking. It's groupthink ast its worst.

Reason was a valid word in context, taken to mean "explanation". Not an explanation by some anthropomorphic incarnation of evolution, but by logical being examining environment, behavior, genome, etc. Replace "maybe" with "because" in your second paragraph and you have a whole load of reasons. The reason for the mutation is an imperfect copying process, and the reason the mutation sticks or not goes along the lines of what you were saying.

Re:Give to 1 area, ur taking from another

[jtollefson]

Living a sedentary life style leads to chair-butt, it's a fact, and proven.

Just look around the cubicle farm. =)

Re:Give to 1 area, ur taking from another

[7-Vodka]

I can tell you right now what the negative results are likely to be.
The super mice are less adept at surviving periods of starvation.

We're living in an age where some humans have conquered hunger and can eat as much as they want, when they want. Yes, much of the worlds population may not have all the food they want, but enough of us do that we have the luxury to get between a chair an computer screen and be oblivious to hunger.

The reason these genetic inhibitors have probably evolved is to stop the organisms from squandering food energy, allow them to live on a meager intake and increase their chances of survival during extreme starvation periods. Muscle tissue requires 50kcal/lb/day to sustain with zero activity in a typical human.

Now they also claimed in the video that those mice put on more fat. I am less sure about this effect. This again is possibly because the mice didn't evolve in conditions of plentiful food and being able to put on more fat in these conditions wasn't necessarily such a large evolutionary driver.

Let's acknowledge the parent's post for his insight though. Every evolutionary change to genetics has a benefit-risk profile and while the benefits of turning off this particular suppressor seem to be obvious, many items on the risk side could still exist and just not be so easy to spot.

Re:Give to 1 area, ur taking from another

[viperidaenz]

unless bones, ligaments, tendons, joints etc aren't too good at keeping up with increased forces put on them by the stronger muscles

Re:Give to 1 area, ur taking from another

[AaronLS]

Yeh, if there is a process that has evolved/design(whatever your belief system is) to specifically limit muscle growth, then there is indeed likely a negative side effect to disabling limiting process. Perhaps animals without this regulator burned more calories and thus had to consume more food than was available to survive. Thus the mammals that developed that limiter were able to survive longer on less food. That's just one speculation, but the point is there should be alot of study into the side effects of this.

Re:Give to 1 area, ur taking from another

[AaronLS]

How did this get an insightful mod? Clearly flame bait. The commenter didn't put any emphasis on the word designed.

They were just pointing out, regardless of whether you believe in evolution or creationism, that there is likely some purpose served by the presence of a limiting hormone. Thus, by eliminating that trait, you can expect there might potentially be side effects. Of course it might be some evolutionary artifact that is no longer necessary in today's environment, but I wouldn't place bets on that.

It's like some layman who doesn't understand the purpose of a firewall going and disabling it and saying "Hey look how much faster our internet is now that this stupid firewall isn't having to inspect packets".

This is a gift horse we absolutely need to look in the mouth.

Re:Give to 1 area, ur taking from another

[weazzle]

Opinions on whether mice were "designed" are irrelevant to what was observed in this study. Whether the body was designed or not, there must be a reason that the NCOR1 regulator exists. Why else would the body hold back a beneficial modification, such as increased strength. I am guessing the reason for the regulator is to decrease metabolic rate. Animals might not be able to sustain themselves if they had to eat so much more frequently.

Re:Give to 1 area, ur taking from another

[WildBlueYonder]

But by that logic, leading a sedentary lifestyle will lead to long life. Everyone is different and some people put on muscle mass way faster than others, just from their natural genetics. Being able to put muscle on easier than average is far from a sure ticket to a heart attack.

So you are saying that either hulked out mutated muscles are the healthiest way to live, or a sedentary person that never moves a muscle is the healthiest way to live?

No room in your hypothesis for a middle ground that doesn't go all the way to one enormous extreme being the best?

Re:Give to 1 area, ur taking from another

[Chrontius]

As long as you work gently, you can get the tendons, bones, and their attachments to grow a good bit without any real trouble. It's just not instantaneous, and shifts the burden of "what grows slowest" away from the muscles themselves.

Once we're there, then we can work on gene therapy for the tendons and bones.

Re:Give to 1 area, ur taking from another

[Carnildo]

Natural selection results in 'good enough' genetics. There isn't any reason why people couldn't have eyesight as good as predatory birds (though some diet changes would be needed), or hearing as good as bats, or olfactory senses as good as canines, etc. but the conditions under which we evolved did not include pressures that selected for senses beyond our current state. Our sense were not maximized, simply good enough for most to survive, and that is natural selection's ultimate standard.

There are tradeoffs involved here. There's only so much surface area in an eyeball to hold photosensors, and only so many nerve paths between the eye and the brain. Human vision is a compromise: we've got strong color vision, moderate low-resolution peripheral vision, moderate high-resolution central vision, and a balance between day (cone) and night (rod) photosensors. Birds of prey tend to devote almost all their vision to high-resolution central vision, at the cost of peripheral vision (it's easier to sneak up on them), color vision (they can't tell a ripe apple from an unripe one), vision during their "off" lighting conditions (a day hunter is almost blind at night, and vice-versa), or all of the above. Similar tradeoffs exist with smell, sound, and any other sensory system: there's no "best" option, just the one that gives a creature the tools it needs to survive.

Re:Give to 1 area, ur taking from another

[sjames]

Sometimes the compromise is nothing more than food availability. Perhaps 'mighty mouse' would be less able to weather a famine, but that's unlikely in the lab setting.

Re:Give to 1 area, ur taking from another

[Sj0]

Not necessarily.

There are plenty of adaptions that make sense from a survival standpoint that don't make sense from a design standpoint. Immediately apparent, a body would limit growth in an environment where food is scarce. The increased protein required wouldn't hurt a rat in a cage fed a balanced diet, but could cost a rat in the wild its survival. Hence, despite having a more powerful body without real consequences, the mouse with this gene would be less survivable and thus the trait would be phased out over time.

Re:Give to 1 area, ur taking from another

[f()rK()_Bomb]

Not for everyone. I have to over eat a huge amount to put on weight, like 3.5k or 4k calories a day. And even then I'll only gain it really slowly and very evenly. I build muscle in the blink of an eye and fat just melts off naturally if I eat a normal amount of food without any effort. My ex is pencil thin no matter what she eats, literally doesn't gain mass. And she's uber unfit, contains no muscle.

So no, sedentary lifestyles do not lead to chair-butt in all people. It's actually a proven fact. There's a very good horizon documentary where they got people to eat 10k calories a day. Some of them gained lots of weight, some barely changed at all, and one group quickly gained and lost the weight naturally.

Re:Give to 1 area, ur taking from another

[g0bshiTe]

The body is designed. It's designed by the cells that make up the body.

Re:Give to 1 area, ur taking from another

[g0bshiTe]

I also submit we are talking lab mice, which were if not mistaken bred by man for specific use in a lab for specific traits, in which case "designed" is a good description of these mice.

Re:Give to 1 area, ur taking from another

[Courageous]

Oh, there are probably selection reasons, but this doesn't prevent human applications, because the recent 1M years of evolution and selection pressure may have no relevancy at all to the human context. Consider human age limits? Why is the human not evolved to live longer? The answer is probably "there was no particular evolutionary need/utility for that". I.e., once you have birthed children and raised them to adults, you have no further "use" to your selfish gene. Defeating that is beneficial to us, but not evolution.

Re:Give to 1 area, ur taking from another

[thomas.galvin]

There's a very good long-term reason: starvation.

In centuries past, there was a very good probability - almost a certainty - that you would undergo occasional, extended periods of lack. An animal that has too much unnecessary muscle mass would be less able to survive this deprivation.

Modern, industrialized humans don't have this problem, though. If anything, we suffer from too little lack. We never fast, and the genes that carry out repairs during times of fasting never get turned on.

From a health perspective, people with more muscle mass are more likely to survive, period. When someone dies of "old age", it's generally because they don't have enough body mass to support their organs.

There might be some other long-term problems with these modifications - fucking around with the genome is kind of a novelty right now - but on the face of it, this seems like it could be a good thing. Particularly to people with a muscle wasting disease.

Wait a minute.

[Zironic]

I have this sneaking suspicion that if genome 'brakes' are present in most animals, they're probably there for a reason.

I wonder what sort of long term side effects you'd be looking at with vastly increased muscle growth.

Re:Wait a minute.

[Pharmboy]

I wonder what sort of long term side effects you'd be looking at with vastly increased muscle growth.

The kind that Hitler was looking for. Best case scenario, you get parents who try to guarantee their child is the next star quarterback. Just imagine, a world full of quarterbacks. Well, except for the poor people.

Re:Wait a minute.

[jellomizer]

You are working under the impression that evolution works optimally. It doesn't evolution usually reaches a good enough state. It may be the case the reason why mice are not stronger is that the ones who were stronger didn't have any better chances then the ones who weren't or their extra bulk end up either being unattractive to the opposite sex or they were too strong and created damage to their mate. Or just just because the extra strength didn't help much more overall so his genes kinda just got washed out over time.

Re:Wait a minute.

[Zironic]

The most intuitively obvious answer is that if your muscle growth can't be limited you're more likely to starve to death during famines.

However I wouldn't be surprised if unchecked muscle growth also leads to bone/tendon damage/poor muscle control/heart issues etc.

Re:Wait a minute.

[Tanuki64]

I have this sneaking suspicion that if genome 'brakes' are present in most animals, they're probably there for a reason.

The problem is, that there is a huge amount of muscle tissue, but the blood supply is insufficient. Those animals (and humans) are not that much stronger, than normal ones, but their endurance is tremendously lower.

Re:Wait a minute.

[Tanuki64]

You miss the problem. It is a gene defect for a reason. The muscles are growing, but the blood vessels don't adapt accordingly. This gives those animals (there are humans with this defect, too), a tremendously lower endurance. Definitely anti-quarterback.

Re:Wait a minute.

[calzplace]

I wonder what sort of long term side effects you'd be looking at with vastly increased muscle growth.

Side effects: giving wedgies to geeks, and having sex with cheerleaders? Sign me up!

Re:Wait a minute.

[hAckz0r]

Easy. More muscle mass equals less flexibility, slower movement, and inability to climb through small holes. With that your probability of being eaten climbs dramatically. Mice that are eaten do not reproduce very well, so the non-augmented mice father the next generation, absent of this modification.

.
Its just like 'white' mice. How many white mice do you see in the wild? Only escapees I'd bet. I once had an albino chipmunk in my back yard, and he lasted about a week before a hawk caught up with him. He didn't even get old enough to have his own family. :-(

Re:Wait a minute.

[Defenestrar]

That's right, if God had intended for us to manipulate genomes He would have given us... actually, that ends rather crudely.

Try this one: If scientists were meant to manipulate genomes they would have won grants by knowing how to use their delicate instruments.

Ah, that didn't go terribly well did it. Let me try a car analogy: there's nothing wrong with taking off the brakes if you have taken alternative steps to achieve proper protection.... Like expert handling or using the stick to really gear down.

Regenerative braking perhaps?

Re:Wait a minute.

[mangamuscle]

Nobody seems to comment on the obvious, the gene helps fight famine! Nowadays in developed countries this might not seem like a feature, but for the early cro magnon, having too much muscle when there was little to eat might have been the only reason they could emigrate all over the world while the bigger (and stronger) gorillas never left africa and never attained massive population growth.

Re:Wait a minute.

[shadowrat]

according to the article, the mice with unchecked muscle growth also gained speed and endurance beyond a normal mouse. They even provide some video showing how well a supermouse can perform on a treadmill vs a normal mouse. They had cute little mouse treadmills.

The article also notes that they have not yet identified any negative effect on the mice. In fact, they say the super mice are all around healthier.

There may be some negative aspect (beyond needing more food), but TFA makes it sound like this process does indeed produce a superior quarterback. At least it does in mice.

Re:Wait a minute.

[Tanuki64]

Maybe... A few posts above I added some links with a certain brand of cattle with the same or similar gene defect. In the documentation I once saw about those, this was their major problem. But of course, between a ton of cattle and a few grams of mouse there might be a difference.

Re:Wait a minute.

[Anonymous Coward]

Easy, you can only get as big as your food supply allows you to cause the bigger you are, the more energy it takes to keep you going.
If you check history, as humans have gotten control of our food supply, we have been getting bigger too (not just fatter).
The bigger you are the more likely you are to fight off predators which is a major survival benefit but the second food supplies get slim, you are the first to starve to death.

Re:Wait a minute.

[boristdog]

I have a theory that the rash of kids that were injected with HGH to make them taller (because their parents wanted them to be more successful) in the 1980's and 1990's will start dropping dead of heart attacks in about 10-15 years because their hearts did not grow large enough to support their increased height.

I knew several rich kids who's parents got them growth shots when I was a teacher in 1990, and I suspected then that it may not be a good idea. This may be a case where the meek do inherit the earth.

Re:Wait a minute.

[Anonymous Coward]

There may be some negative aspect

Obviously. They get stuck trying to get through mouseholes - not a pretty ending. Of course, the scientists probably didn't test this.

Re:Wait a minute.

[ChromeAeonium]

I wouldn't be surprised if unchecked muscle growth also leads to bone/tendon damage/poor muscle control/heart issues etc.

I think that would probably be the most likely scenario, if not simply because people with these sorts of mutations IIRC tend to have shortened lifespans and various health issues. There's something to be said about how biology doesn't give a crap about how a gene got there and all, and that activating something doesn't necessarily mean there will be side effects, but we're talking about genes that affect the growth and development of the physiology of the animal here, not some gene that will have no other affect besides producing a fluorescing protein or green fur or something like that. No, evolution doesn't always work out nice and smooth, but it does do some honing over millions of years, and this does change something that the rest of the animal has not honed to. It's possible that this will have no effect on the animal's health, but my guess is that accommodating the rest of the body with a stronger heart, bigger bones, and better tendons to suit these changes may be the Required Secondary Powers needed to make this trait mean anything beneficial to the mouse.

Re:Wait a minute.

[Anonymous Coward]

In the Cattle species with double-muscling genotypes (Belgian blue and others), the extra muscle mass does have an obvious detrimental effect on the cattle. Specifically, the cows have a much harder time birthing as the muscles of the birth canal are also enlarged (effectively making the canal more restricted - which can kill both the cow and the calf). Many of the farmers there control the breeding to favor the heterozygous genotype. I'm not familiar enough with mouse anatomy to be able to say if some similar effect could happen or not, but it wouldn't surprise me.

Re:Wait a minute.

[cyberchondriac]

A little OT, but I have never understood why the body evolved such that in times of a severe calorie deficit, it will burn muscle before it burns it's fat stores, by default. That's not entirely accurate, it burns both, but muscle has the lower priority. It can be somewhat prevented by heavy exercise, but it would seem to me to make more sense to just go for the fat first, and then if things continue to be that bad, *then* start eating up muscle tissue.

Agreed about the potential for heart issues and/or tissue damage. Maybe it won't, but I don't wanna volunteer.

Re:Wait a minute.

[Bucky24]

I have never understood why the body evolved such that in times of a severe calorie deficit, it will burn muscle before it burns it's fat stores, by default.

As far as I understand, it takes less energy to burn muscle then it does fat. So the body is going for the process that will require the least energy expense (which could be important in a severe calorie deficit). The reason it doesn't make sense is that we might require our muscle in order to get more calories, but I don't think the lower level brain makes that kind of a distinction. It's not worried about surviving the next week, it's worried about surviving RIGHT NOW.

Re:Wait a minute.

[Eivind Eklund]

That sounds likely if we haven't had supporting evolution of the bone/tendon/etc genes.

My intuition at why we'd have this is slightly different than yours: My first feeling is that it would be likely to be part of the system that controls cancer. (I am not a professional in this area, so take it for what it is worth.)

Eivind.

Re:Wait a minute.

[roc97007]

...Good thing it's only happening to mice, then...

Re:Wait a minute.

[roc97007]

I think I saw that movie.

Re:Wait a minute.

[shiftless]

More muscle mass equals less flexibility, slower movement,

Incorrect.

inability to climb through small holes.

Maybe. But in nature there isn't a hole a mouse can't dig larger for himself if needed, to crawl through. Having twice the strength would help with that.

I suspect that a mouse being twice as strong wouldn't help it survive simply because strength isn't something that really keeps mice alive. A snake can catch and eat a muscle-bound mouse as easily as a skinny one.

Re:Wait a minute.

[Krau Ming]

any tissue that is maintained by a population of resident adult stem cells (like skeletal muscle) can only be maintained through a finite number of adult stem cell divisions. at a certain point the telomeres of the DNA get chopped down too far and those cells that have "overdivided" become quiescent, ie: they won't divide any more. this results in that tissue losing the ability to maintain itself.

so the results of this are interesting, but we can only add this gene to the long list of genes that have been identified as "brakes" on tissue growth but have not turned out a practical use yet.

however, for now, professional baseball players and other elite athletes can cross their fingers that some drug compound can be identified to block NCOR1.

Re:Wait a minute.

[St.Creed]

True, that. Also, I would wager that in a starvation situation, it's not the fact you lack muscle which is the biggest issue, but the Ice Age, or bad droughts, or other factors beyond your control. In that case saving as much energy as possible would do more for you than saving muscle. If there's plants or roots to be found, you need very little muscle to eat them.

Re:Wait a minute.

[Anonymous Coward]

I have a theory that the rash of kids that were injected with HGH to make them taller (because their parents wanted them to be more successful) in the 1980's and 1990's will start dropping dead of heart attacks in about 10-15 years because their hearts did not grow large enough to support their increased height.

I knew several rich kids who's parents got them growth shots when I was a teacher in 1990, and I suspected then that it may not be a good idea. This may be a case where the meek do inherit the earth.

HGH studies have shown it can increase the size of internal organs except the brain...though enlarged heart is also a problem I've heard of...

Re:Wait a minute.

[Anonymous Coward]

I have this sneaking suspicion that if genome 'brakes' are present in most animals, they're probably there for a reason.

I wonder what sort of long term side effects you'd be looking at with vastly increased muscle growth.

Pesticides 2.0

Re:Wait a minute.

[Anonymous Coward]

Belgian Blue

Re:Wait a minute.

[Anonymous Coward]

The drawback may be increased energy usage. Why build extra strong and energy expensive muscles if they do not contribute to your ability to produce offspring?

Re:Wait a minute.

[Cyberax]

"beyond needing more food"

That's exactly why it doesn't happen in the nature. It's not that hard to grow additional muscle mass - bodybuilders do this all the time, for example. However, you need quite a lot of additional energy to maintain them.

In case of mouses, additional endurance and strength probably does not offset the increased energy expenditure in nature.

Re:Wait a minute.

[FirephoxRising]

TFA states that they have increased endurance, so it seems that they do not have the same problem as the people you are thinking of.

Re:Wait a minute.

[FirephoxRising]

I'd mod you up if I could. Your post makes sense, in the past we were nearly always short of food. In the west now, we eat too much and I would welcome a treatment that would predispose me to keeping more muscle and helping me burn fat.

Re:Wait a minute.

[Anonymous Coward]

I heard the super mice are addicted to bad techno, cocaine, gold chains and tanning oil.

Re:Wait a minute.

[Larryish]

Where is the video of the musculature-enhanced bull fucking a cow to death?

Or does their junk shrink like the gym junkies?

Re:Wait a minute.

[mmontour]

There's more to life than just "calories". You also need a supply of amino acids to make new proteins (such as enzymes), and if there aren't enough of these in your diet then the only option is to break down muscles or other important tissues. Fat reserves can be used as energy and can even be used to synthesize glucose for the organs that require it, but there's no way to make amino acids from fat.

Re:Wait a minute.

[OrigamiMarie]

Muscles are expensive to maintain. They require lots of calories. In the wild, these mice might not be able to find enough food to support their muscle needs (because extra strength may not translate directly into enough increase in calorie acquisition ability). Also, they live in little underground tunnels, which they dig themselves. More muscular mice are probably bigger-cross-section mice, which means a lot more work to dig out tunnels.

Re:Wait a minute.

[Tastecicles]

Just how wide a tunnel do you think a mouse needs?

Clue: the average house mouse, Mus musculus, is shy of four inches long from the tip of the nose to the base of the tail and normally 2 inches wide. This does not mean that they need a two inch wide tunnel.

I've seen an adult mouse push itself through a hole less than a quarter inch wide. Those little bastards can fold their skulls.

Rats (specifically, norvegicus) are even better. Not only can they squeeze through impossibly small gaps (four pounds of feral rodent through a one and a half inch gap at the base of a wall - yes, they are getting this big when they infest a warehouse full of dry dog food), they can also chew through practically anything (with possibly the sole exception of glass).

Re:Wait a minute.

[angel'o'sphere]

A little OT, but I have never understood why the body evolved such that in times of a severe calorie deficit, it will burn muscle before it burns it's fat stores, by default.

This is nonsense.
Your body will burn muscles as the very last resort. In fact it is quite difficult for the body to do so and it needs several weeks of "transforming" to have the necessary enzymes and hormones ready.
No idea why this "burning peptides myth" is so common in our days. Depending on your constitution your body does not even burn peptides from your daily meals!
It only uses it to build up your muscles. If you eat more than your body can use to build up muscles, it gets just discarded again ... (yeah that is not true for every person, but a huge majority. The only "tribes" that can digest and burn meat without any need to "recalibrate" their body are Inuit and Maori)

Re:Wait a minute.

[Anonymous Coward]

Muscular tissue is ridiculously expensive to maintain in terms of food.
Normal mouse resists longer without food, surviving harsh periods, where super mouse starves.

Re:Wait a minute.

[Courageous]

Enlarged heart is not in and of itself a "problem". Pick out your favorite high endurance athlete. I guarantee you: they have an enlarged heart.

Re:Wait a minute.

[Ramin_HAL9001]

I have this sneaking suspicion that if genome 'brakes' are present in most animals, they're probably there for a reason.

I wonder what sort of long term side effects you'd be looking at with vastly increased muscle growth.

Probably the inability to consume enough food to keep those muscles functioning.

Re:Wait a minute.

[Anonymous Coward]

More muscle will require more energy to burn. A little like having a Ferrari, it is awesome but it would burn a lot of gas, and maybe the mouses doesn't need all that muscle for commuting.

LISP

[Windwraith]

I kind of giggled at the lab's name(on TFA's video). I don't see enough parentheses on it though.

Re:LISP

[sidthegeek]

I don't see enough parentheses on it though.

Lemme guess, you're a Lisp hacker.

(I keed, I keed!)

Obligatory

[sagematt]

I for one welcome our new rodent overlords that come to save the day.

Re:Obligatory

[sortius_nod]

Came for the summary, stayed for the "overlord" comment.

CBS or Man and Machine?

[tepples]

I thought CBS already owned the trademark on "Mighty Mouse" for everything but computer mice.

Re:CBS or Man and Machine?

[sjames]

But if they protest, they could end up with the world's most dangerous rodent infestation.

But the important question is:

[Hartree]

Can the NCOR1 "mighty mice" beat up the PEPCK-C "supermice" from 4 years ago?

So they did mice?

[Tanuki64]

Belgians thought bigger:

http://en.wikipedia.org/wiki/Belgian_Blue

http://www.youtube.com/watch?v=Nmkj5gq1cQU

Re:So they did mice?

[Anonymous Coward]

Belgian Blue, beautiful cow, innit?
But always pining for the dikes...

Re:So they did mice?

[Anonymous Coward]

Different gene expression. Myostatin is what does this to those cows, also check out Wendy the super whippet (sp?) and just search in general for myostatin disorders. There are some people that have disorders related to myostatin expression as well.

Use It or Lose It

[Jah-Wren Ryel]

Seems to me that a whole lot of biological processes follow the "use it or lose it" paradigm. From muscle growth, to brain function and even living itself (get fat and lazy, you die sooner).

So what I'd like to see is research to counter-act that. Instead of a new gene-therapy replacement for steroids, how about something prevents muscle loss even for people who are sedentary? Something to counter-act the "maintenance" requirement to staying fit. That would be really nice.

Re:Use It or Lose It

[Defenestrar]

Scientists do that research too. Bears (and other hibernating animals) are of particular interest here. But humans are (hopefully) approaching a point where famine is not a significant threat to life, so other solutions like this one could also work even though it may increase the metabolic load (in addition to muscle mass) by causing a larger number of mitochondria and higher cellular respiration. (This article's reference paper).

Re:Use It or Lose It

[StikyPad]

Muscle mass does this to some extent, since larger muscles burn more calories at rest. I had a friend in college with a genetic abnormality (it may well have been related to this gene or hormone) who stayed tone and muscular with a sedentary lifestyle. As someone above posted, it could well be that we (and mice) would benefit from such a "condition," but it was perhaps selected against for its high caloric requirements. It could also be that it leads to an enlarged heart and untimely death.

Re:Use It or Lose It

[Anonymous Coward]

Are you sure it was a "genetic abnormality"? I've known dudes before who it seems like can eat a sausage biscuit and gain a pound of muscle. It's not uncommon. The higher one's testosterone level is, the easier it is to keep muscle and lose fat. This is why when taking steroids, you either eat/sleep well and gain plenty of muscle, or you eat/sleep poorly and still gain, or at least don't lose.

BTW, the "enlarged heart" thing is a myth. *Heavy* steroid usage may resulted in an "enlarged" heart for the same reason all your other muscles grow too. This has not been shown to hurt heart function in the least, and in fact it may help.

But finally I don't think

[aglider]

it can actually fly!

Re:But finally I don't think

[Anonymous Coward]

Try again in English, please.

In other news

[pablo_max]

After years of giving his lunch money to and getting atomic wedgies from the local bully, Johan has finally developed the gene therapy which will enable him to finally kick some ass.

I wonder....

[Tanuki64]

...what an elephant with this gene defect would look like.

Re:I wonder....

[Anonymous Coward]

Probably exactly like your mother.

Anyone know how this is different from myostatin

[Mathinker]

Any biologists who can tell me how this is different from what happens when myostatin is blocked? We've known about that protein's regulation of muscle development since 1997.

Big and strong, but

[Anonymous Coward]

how do they treat young boys in the shower?

Oh my poor...

[vikingpower]

...tomcat !

That's a given

[bigsexyjoe]

Scientists take what you've said as a given. The reason animals evolve to put limits on their musculature is too reduce the amount of food they need and too make them more nimble. However, as the article states, a great motivation for switching off this gene is to help people with muscular degenerative diseases.

Tinkering with nature...

[Anonymous Coward]

2 pop culture references come to mind:

1) Blade Runner - "The light that burns twice as bright burns half as long" - Tyrell
2) The Secret of NIMH - "We can no longer live as rats. We know too much." Nicodemus

Arnold says

[HangingChad]

At da Salk Institute for Biological Studies we want to pump....you up!

So it's not Terrytoons?

[Teknophilia]

So, we're getting this: https://en.wikipedia.org/wiki/Mighty_Mouse ?

Re:So it's not Terrytoons?

[Macgrrl]

Mr. trouble never hangs around, when he hears this Mighty sound, Here I come to save the day! That means that Mighty Mouse is on the way! Yes sir, when there is a wrong to right, Mighty Mouse will join the fight! On the sea or on the land, He's got the situation well in hand!

Bully Whippets and Mighty Mice

[brianerst]

This has been done before with a different knockout gene. Alexandra McPherron and Su Jin-Lee created "mighty mice" by knocking out the MSTN gene back in 1997. Same sorts of effects - doubled muscle mass, increased endurance and the like. There is a lot of hope in the muscular dystrophy arena that these types of knockout effects can be replicated via drug delivery mechanisms.

These sorts of mutations also occur naturally. I have a whippet and a naturally occurring mutation occasionally results in a bully whippet, which looks like the Incredible Hulk of whippets. In this case, the muscles don't just double - these dogs can pack on a whole other dog's worth of weight in added muscle. They are absolute freaks of nature - but with the same docile temperament that normal whippets have.

It's a result of a myostatin mutation. If a dog has one copy of the gene, they are incredibly fast runners with just a slight increase in muscle mass - these are the best racing whippets. If a dog is born with two copies of the mutated myostatin gene, they become "bullies". Forget six-pack abs - these guys have an entire case...

Aren't we touchy...

[mevets]

Most beings are sufficiently well organized that is very much as if they were designed. Although I disapprove of needless capitalization, to use the ideologically correct version of his statement might be something like: ... because the body evolved to only grow so much in that area, there is likely a specific disadvantage to making it otherwise....
It is more than just correct, it is technically correct, thus should please the petty pedants.

Personally, I prefer the abstract application of 'design' and 'reason'. It keeps the attention on the aberration of juicing a mouse rather than cow-towing to ideological sensibilities.

Re:Aren't we touchy...

[nedlohs]

"likely" and "must be" are very different.

"a specific disadvantage" and "a LONG TERM REASON" are very different.

Your words are general and hedged. The original claims are specific and set in stone.

I agree, here is likely some reason animals aren't supercharged like this already - most likely in my mind would be energy requirements (weaker but needing less food leads to better survival than stronger but needing more food) but I know nothing about the specifics or if there are even additional energy needs.

only problems are

[swschrad]

(1) the mice are only black and white, and (2) they can only move at 24 frames per second.

Gee, Brain, what do you want to do tonight?

[Arancaytar]

The same thing we do every night: Use your super-strength and my wits to take over the world!

Re:Gee, Brain, what do you want to do tonight?

[Kinnison]

I, for one, welcome our new rodent overlords!

finally...

[cas2000]

maybe the stupid hysterical bullshit about drugs in sport will eventually end. gene tweaking and gene transfer, taking enhancement drugs, prosthetics, absurd training regimens - it's bullshit to pretend that one (the last) is any more "natural" (and therefore allowable) than the others.

Rawr

[Anonymous Coward]

Great....Now it's only a matter of time before athletes turn to petmeds.com

I thought as I read the title

[Anonymous Coward]

that Apple has improved their computer mouse.

Survival...

[linatux]

A mouse needs to be able to run at full speed under a closed door. Otherwise it may be hacked to death by the bloke chasing it with a carving knife (or eaten by the kitty)

Re:Anyone know how this is different from myostati

[slew]

IANAB, but...

NCoR1 (nuclear receptor corepressor number 1) is coregulatory protein which (according to this paper) apparently inhibits MEF2 (myocite enhancer factor number 2) and PPAR (peroxisome proliferator-activated receptor) and ERRs (estrogen related receptors). MCoR1 is encoded by the NCOR1 gene. Since it is a co-regulator, blocking the expression of this gene will allow for more MEF2, PPAR, and ERRs activity causing more muscle generation and more mitochondrial activity (according to this paper anyhow). There are four MEF2 variants in humans which all seem to do slightly different things. Not sure how all these things work with NCoR1. PPAR and ERRs on the other hand deals with mitochondrial activity. Increase mitochondrial efficiency might mean more efficient conversion of sugar into energy..

On the other hand, Myostatin is a growth factor (TGF8) that generally inhibits muscle development. Myostain is encoded by the MSTN gene (in humans). Blocking this growth factor seems to increase muscle development by increasing muscle fiber size. There seems to be some indication that myostatin somehow just keeps muscle stem cells from differentiating into muscle cells (by promoting the formation of MyoD) and that if you knock Myostatin out, then those muscle stem cells just become muscle cells. Other indications are that myostatin inhibition also inhibits MEF2C (one of the 4 human MEF2 variants). Also, in some studies, inhibiting Myostatin increases the number of fast glycolytic (type IIB or so called fast-twitch) fiber which develop. However, myostatin seems to do the opposite for tendons, so where you are stronger, your tendons might get more brittle.

Not sure how the former is different from the latter, but if it can promote more type I or type IIA muscle rather than type IIB and if there is an increase in mitochondrial genesis (allowing more energy/power), that would be a difference.

I for one

[Anonymous Coward]

welcome our new musculous mus musculus overlords.

Oh, according to HHGTG they were already our overlords. Meet the new boss, same as the old boss.

Re:Anyone know how this is different from myostati

[mesterha]

I'm curious how this is related to thyroid hormones. Is the linked article incorrect?

Thanks,

Humm

[carvalhao]

Same mouse footage than Resveratrol?

Re:Anyone know how this is different from myostati

[slew]

I'm curious how this is related to thyroid hormones. Is the linked article incorrect?

Thanks,

NCOR1 apparently can be called TRAC-1 (thyroid-hormone- and retinoic-acid-receptor-associated co-repressor 1) as described in this wiki article

It is a misnomer to say NCOR1 is a thyroid hormone as I believe the NCOR1 protein really operates on the Thyroid hormone receptors and modulates their response and is thus working in (or near) the muscles in this case, not anywhere near the thyroid.

myostatin

[Anonymous Coward]

inhibiting myostatin will do the same thing.. to see what it looks like in nature, google: myostatin bulls

OK, now fix the joints.

[Tastecicles]

My arthritic hands are so weak now, it's silly. I have to use an aid to open a bottle most times (it's not funny, I'm 36). If this gets FDA approval I see benefits in rebuilding muscle tissue lost due to atrophy. The problem with arthritis, atrophied muscles are only a symptom which is exacerbated with other conditions such as I had (CTS). Now they need to fix the problem of heavily worn cartilage, and I for one am not much keen on the idea of mechanical replacement. Yay science!

earthworm jim

[Anonymous Coward]

earthworm jim,
the soil he did crawl
earthworm jim,
a super suit did fall.

jim was just a dirt eating,
chewing length of worm, flash
but all that came to a crash
and gave him lots of power

earthworm jim,
he's such a groovy guy
earthworm jim,
he rocket's through the sky

cruising through the universe
having lot's of fun,
here comes earthworm jim you know
that he's the mighty one
--- look out ---

la la la la, la la la la, la la la....

despite his great big muscles
and his really big ray gun,
jim is still an earthworm
but then he's the only one,

with a super suit to make him really super strong,
jim can be a winner if we only sing along...
(alright)

earthworm jim,
we think he's mighty fine
earthworm jim,
a hero for all time

earthworm,
earthworm,
earthworm,

earthworm, jim
hooray for jimmmmmmmm

source: http://www.lyricsondemand.com/tvthemes/earthwormjimlyrics.html