Double muscled whippets

[labsnlurchers 39]

Hi all,

 

My name is Jen Jensen; Heather asked me to join up and fill in some of the blanks on the double muscled whippet. I was the person who initially contacted the Ostrander Lab about the bully whippets and then worked on getting a genetic test developed.

 

I'm not sure where to start...maybe with the "carriers are faster" thing. The sample size of the original study was extremely small, less than 100 whippets used to establish that "carriers are faster than non-carriers". That alone makes the results a little dodgy. Additionally, there are four different racing organisations in North America and the study used dogs who ran in only one of the organisations. That automatically removed most of the West Coast dogs from the study and most of the show-bred dogs. The show-bred dogs are generally D dogs and, insofar as pedigrees are concerned, the West Coast dogs are generally the fastest. The Ostrander Lab folk wouldn't know that but, by using only that one racing organisation, they skewed their results towards "the fast dogs are carriers" idea.

 

We've now had a test available for almost a year. Since that time, the whippet racing community has been testing their dogs and (more importantly) sharing their dogs' test results with the rest of the community. I've been tracking test results in my pedigree database and, with results for over 200 dogs (in other words, roughly three times the sample size used in the original study), it does not appear that carriers are faster than non-carriers. In a sample of mostly race-bred whippets, the percentage of carriers stays about the same, regardless of the dogs' speed.

 

As for amount of muscling, Wendy's breeder calls her "the mother of all bullies". She is pretty much the most extreme example of double muscling one could imagine. It was her birth that prompted her breeder and me to start looking into the whole issue (I own a half-brother of hers and am a friend of her breeder). Without Wendy and her owner, it's unlikely we would have got so much accomplished so quickly. Wendy was made available for a myriad of tests and donated more than a few vials of her blood for various scientific works.

 

She really does look like that and no, she doesn't take steroids. Like other DM whippets, she suffers from cramping, sometimes severely. It really depends on the individual dog. As far as I know, the heart is not affected by the myostatin mutation; myostatin is involved in the formation of striated muscle tissue (voluntary muscles) and all organs (heart, diaphragm, and other involuntary muscles) are made up of smooth muscle tissue.

 

Myostatin is not the only substance affecting muscle development and so the amount of muscling in carriers and affected whippets varies widely. The photos published in the original study (and reproduced here) are a little misleading. Of the non-carriers (the left-hand column), the top and bottom dog are race-bred whippets from Europe. I own the dog in the upper left photo; that photo was taken when he was a year old so not yet fully developed. Even though the myostatin mutation also exists in the European gene pool, European racing whippets are smaller and slighter than their North American cousins. Additionally, the dog in the lower left photo was around 8 or 9 when that photo was taken; needless to say, he wasn't in his prime as far as muscle definition goes. The third non-carrier is a show-bred dog; they are also much slighter than dogs bred for racing. The photos of the three carrier dogs (centre column of photos) were all taken while the dogs were at the peak of their racing careers. They don't look much different than non-carriers at the peak of their careers.

 

As an example of this, here are photos of two of my dogs; one is a carrier and one is not.

 

The first:

 

 

 

And the second:

 

 

 

As you can see, the fawn dog (Tighe) is more heavily muscled than the black dog (Dayton). Tighe is NOT a carrier and Dayton is (he is, in fact, Wendy's half-brother).

 

Labsnlurchers, yes you've got the inheritance of the gene correct and yes, you could breed a DM whippet to a non-carrier to get an entire litter of carriers. However, there wouldn't be any benefit to it as, once you look at a larger sample size, it's pretty clear that carrier-status does not necessarily make a dog faster against other dogs.

 

As far as dogs are concerned, the gene has only been identified in whippets. It also occurs in cattle, mice, and humans.

 

I don't know of any North American whippet breeders who are interested in producing DM whippets. All the race breeders I know have tested their breeding stock and will NOT perform any breeding between two carriers.

 

I hope that answered some questions for you all. If there's anything else you'd like to know, just ask.

 

thank you for sharing that information with us, all the info i found was suggesting that double muscle carriers were faster in general than the wild type whippet and i see how the photos have been used in a way to skew the readers view towards supporting the findings.

thanks again

oh and welcome to THL x

[jamestwo 0]

very interesting read thanks to all concerned

[sandymere 8,263]

Excellent stuff I was worried that we were going to get an upsurge in breeding for this gene that would spill out intto lurchers with the implications of litter wastage that would bring. Just one ? if cardiac muscle is not involved but likely increased workload via higher metabolic rate 2nd to increased size are there any longer term health problems? and another you mentioned studies being done are there any on the lactic shuttle/potassium lvel in the mucles?

thanks s

[Jensen 0]

Hi again,

 

I should really clarify that I don't believe the study was deliberately skewed to produce certain results. The specifics I noted in my previous post (like the demographic make-up of racing whippets in different regions of North America) or even the difference between European and North American whippets could not have been known by the scientists at the Ostrander Lab.

 

Sandymere, there were never any specific studies done of the muscle tissues so there's no way to know the exact impact on the heart. Apparently, there are two types of double muscling; in one, the number of muscle fibers are doubled and in the other, the number remains the same but the physical size is doubled. Each type would presumably have a different affect on the heart but we have no idea what type of double muscling actually occurs in whippets.

 

As I mentioned in my previous post, myostatin is not the only known muscle development regulator; that's why carriers can be of a slighter build than non-carriers and also why there can be the rare affected whippet capable of racing. No one seems to know how myostatin interacts with those other substances and how they in turn work with the cardio-respiratory system. There really haven't been many double-muscled whippets born in North America so long-term affects are a big unknown.

 

So, it's really a big question mark for all of us. Maybe the cramping is the body's way of not putting too much strain on the heart. Who knows?

 

If you wanted to research it further, I'd start by looking at papers coming out of Johns Hopkins (Lee, I think, is the scientist's name). His work focuses on Duchenne's muscular dystrophy and I think he was the one who engineered the myostatin knockout mice. There might also be some new research on MD and myostatin being done at one of the universities in the "research triangle". I've just heard about that in passing so don't know which uni.

[Brimmer 220]

This Thread just keeps getting better and better, Keep up the good work!

I don't know a lot about whippet's but this is fascinating reading!

[Headshot08 36]

Great topic wouldnt mind one of them single gened whippets looks very handy anyone know where they are bred?

 

 

Steve

Edited November 2, 2008 by Headshot08

[les 0]

Hi all,

 

My name is Jen Jensen; Heather asked me to join up and fill in some of the blanks on the double muscled whippet. I was the person who initially contacted the Ostrander Lab about the bully whippets and then worked on getting a genetic test developed.

 

I'm not sure where to start...maybe with the "carriers are faster" thing. The sample size of the original study was extremely small, less than 100 whippets used to establish that "carriers are faster than non-carriers". That alone makes the results a little dodgy. Additionally, there are four different racing organisations in North America and the study used dogs who ran in only one of the organisations. That automatically removed most of the West Coast dogs from the study and most of the show-bred dogs. The show-bred dogs are generally D dogs and, insofar as pedigrees are concerned, the West Coast dogs are generally the fastest. The Ostrander Lab folk wouldn't know that but, by using only that one racing organisation, they skewed their results towards "the fast dogs are carriers" idea.

 

We've now had a test available for almost a year. Since that time, the whippet racing community has been testing their dogs and (more importantly) sharing their dogs' test results with the rest of the community. I've been tracking test results in my pedigree database and, with results for over 200 dogs (in other words, roughly three times the sample size used in the original study), it does not appear that carriers are faster than non-carriers. In a sample of mostly race-bred whippets, the percentage of carriers stays about the same, regardless of the dogs' speed.

 

As for amount of muscling, Wendy's breeder calls her "the mother of all bullies". She is pretty much the most extreme example of double muscling one could imagine. It was her birth that prompted her breeder and me to start looking into the whole issue (I own a half-brother of hers and am a friend of her breeder). Without Wendy and her owner, it's unlikely we would have got so much accomplished so quickly. Wendy was made available for a myriad of tests and donated more than a few vials of her blood for various scientific works.

 

She really does look like that and no, she doesn't take steroids. Like other DM whippets, she suffers from cramping, sometimes severely. It really depends on the individual dog. As far as I know, the heart is not affected by the myostatin mutation; myostatin is involved in the formation of striated muscle tissue (voluntary muscles) and all organs (heart, diaphragm, and other involuntary muscles) are made up of smooth muscle tissue.

 

Myostatin is not the only substance affecting muscle development and so the amount of muscling in carriers and affected whippets varies widely. The photos published in the original study (and reproduced here) are a little misleading. Of the non-carriers (the left-hand column), the top and bottom dog are race-bred whippets from Europe. I own the dog in the upper left photo; that photo was taken when he was a year old so not yet fully developed. Even though the myostatin mutation also exists in the European gene pool, European racing whippets are smaller and slighter than their North American cousins. Additionally, the dog in the lower left photo was around 8 or 9 when that photo was taken; needless to say, he wasn't in his prime as far as muscle definition goes. The third non-carrier is a show-bred dog; they are also much slighter than dogs bred for racing. The photos of the three carrier dogs (centre column of photos) were all taken while the dogs were at the peak of their racing careers. They don't look much different than non-carriers at the peak of their careers.

 

As an example of this, here are photos of two of my dogs; one is a carrier and one is not.

 

The first:

 

 

 

And the second:

 

 

 

As you can see, the fawn dog (Tighe) is more heavily muscled than the black dog (Dayton). Tighe is NOT a carrier and Dayton is (he is, in fact, Wendy's half-brother).

 

Labsnlurchers, yes you've got the inheritance of the gene correct and yes, you could breed a DM whippet to a non-carrier to get an entire litter of carriers. However, there wouldn't be any benefit to it as, once you look at a larger sample size, it's pretty clear that carrier-status does not necessarily make a dog faster against other dogs.

 

As far as dogs are concerned, the gene has only been identified in whippets. It also occurs in cattle, mice, and humans.

 

I don't know of any North American whippet breeders who are interested in producing DM whippets. All the race breeders I know have tested their breeding stock and will NOT perform any breeding between two carriers.

 

I hope that answered some questions for you all. If there's anything else you'd like to know, just ask.

 

thank you for sharing that information with us, all the info i found was suggesting that double muscle carriers were faster in general than the wild type whippet and i see how the photos have been used in a way to skew the readers view towards supporting the findings.

thanks again

oh and welcome to THL x

what if these dogs were not worked what would they look like

[les 0]

has some pitbulls got this gene

[mikecat1 0]

this looks like mike from the teifi inn lol

[halfmoongh 0]

No, they do not, neither do greyhounds.

 

Having a carrier would be of no advantage since they are not necessarily any faster than a non-carrier.

 

Thanks again Jen for coming on and sharing all about the study and test available.

 

Heather

 

has some pitbulls got this gene

[Terrier man 38]

i think that its just whippets in dogs but i know mice and cows have it. If they got one copie, they are fine, just faster but if two dogs each with one copy (unknown without testing genetically) are crossed then the litter wil be 25% double muscled 'bullies'

 

 

In cattle iv witnessed it first hand.. a charlois bull calf he turned out to be disabled over it poor fecker couldnt even walk after a bit made it too the age of 2 and half and died looked like one hell of a beast it was just muscle growing on muscle but his knees went with all the weight...

[rattingrob 0]

I should not think a breeder would breed a single gened whippet intentionally. If everyone did it then years down the line there's a basket load of trouble in the gene pool as every dog would be single gened with the potential of producing Bully pups in future matings. Responsible breeders would not want this to happen, culling of "useless" Bully pups in a litter just to get single gened ones and you're heading down the path of some "pedigree" breeds that have known genetic defects and pups carrying the defect (or not in the case of ridgebacks) are simply pts within the first few weeks of life or simply spend their entire lives suffering all for the glory of their littermates being possibly "normal".

 

It's simply not on.

[rattingrob 0]

Tend to find a "bully" whippet cannot stick the pace and is slower than the half/half whippets. There have been a few in the racing and for the majority 150yds is just too far for them and they will drop off behind at about -100yds. Bully's can also tend to be more susceptable to cramps, the same amount of blood as a non-bully trying to carry the same amount of oxygen around two or three times more muscle cells.

 

Note: Not to be confused with Bull x Ghd or Bull x Whippet.

 

 

Even though I know nothing about Whippets, I do know that big dogs and little dogs don't have the same amount of blood! They produce the amount of blood required by the body(hence the fact you can donate it!). With muscles of that size their probably carrying pints more than a standard Whippet! Even things like veins would be much larger due to the blood flow to the larger muscles(compare a guys forearm to that of a woman)

One thing though you would of thought they'd have quite high blood pressures? (when the muscles contract and force the blood back into the veins)

I believe cramps are caused mainly by the build up of lactic acid in the muscles.

JMO

 

Luke.

 

I was attempting to give an example in terms of two animals of the same "size" (height, bone structure etc) otherwise you could say a fat person has more blood than a thin one because they're bigger. There would be no use making a straight comparison between say a terrier and a great dane as common sense would tell you that you must work on equivical terms.

The reason the lactic acid builds up is because more of it is produced due to there being more muscle, now if there were propotionately more blood in the larger massed individual then it would be able to carry the lactic away to the kidneys at just the same rate as in a lesser muscled person with less blood (if you believe that the Blood:Mass ratio is the same in everyone ie. greater mass = proportionally greater amount of blood).

Edited November 3, 2008 by rattingrob

[sandymere 8,263]

Hi again,

 

I should really clarify that I don't believe the study was deliberately skewed to produce certain results. The specifics I noted in my previous post (like the demographic make-up of racing whippets in different regions of North America) or even the difference between European and North American whippets could not have been known by the scientists at the Ostrander Lab.

 

Sandymere, there were never any specific studies done of the muscle tissues so there's no way to know the exact impact on the heart. Apparently, there are two types of double muscling; in one, the number of muscle fibers are doubled and in the other, the number remains the same but the physical size is doubled. Each type would presumably have a different affect on the heart but we have no idea what type of double muscling actually occurs in whippets.

 

As I mentioned in my previous post, myostatin is not the only known muscle development regulator; that's why carriers can be of a slighter build than non-carriers and also why there can be the rare affected whippet capable of racing. No one seems to know how myostatin interacts with those other substances and how they in turn work with the cardio-respiratory system. There really haven't been many double-muscled whippets born in North America so long-term affects are a big unknown.

 

So, it's really a big question mark for all of us. Maybe the cramping is the body's way of not putting too much strain on the heart. Who knows?

 

If you wanted to research it further, I'd start by looking at papers coming out of Johns Hopkins (Lee, I think, is the scientist's name). His work focuses on Duchenne's muscular dystrophy and I think he was the one who engineered the myostatin knockout mice. There might also be some new research on MD and myostatin being done at one of the universities in the "research triangle". I've just heard about that in passing so don't know which uni.

Thanks for reply, i was thinking along the lines of processes in the muscle rather than causes of the growth but very interesting subject in it's own right

Cheers s

[Arne 0]

Hi jensen

 

All this information you have on DM whippets are very interesting. Do you know, if DM have been found in european whippets?