Clones, why are epd not the same?

[Son of Butch]

Why doesn't the Final Answer Clone aaa 17320042 have same epds as Final Answer aaa 13592905 if they are genetically the same?

The Clone is rated 5 ce better and bw 1/2 lb lighter also doc 5 lower than the original (though lower acc for each)
ie
Clone 17 ce Original ce 12 (both are as of 6/4/15)
17-12 = 5
5 is 41.7% of 12 therefore 17 is a 40% improvement over 12 or you could say 30% difference between a 12 and 17 score.

Could it be clones aren't the same?
OR
Is the Clone vs Original comparison revealing a 30-40% margin of error in the way epd information is collected and determined?

 

[dun]

I wondered about that too. Some years back ABS had a a pair that were an embryo split. They didn;t even look relatedand their EPDs were way far apart.

 

[Katpau]

The Epd's of the original Final Answer are based on the data turned in on tens of thousands of calves by thousands of different owners. The Epd' of his clone are based on a genetic evaluation that looked at the markers in his DNA and compared them to the markers in the DNA of proven bulls and then estimated how his Epd's might fall. Both are estimates, but the old Final Answer has much more accuracy and you are much more likely to see the results predicted. No two beings are exactly the same, even when one is a clone. All are influenced by both their DNA and their environment. This includes the environment of the womb from the time of conception. As I understand it, the embryo is affected in small part by the female who carries it in her womb. With clones, that female is different from the one that gave birth to the original animal. There is something called mitochondrial DNA that will affect the development of an embryo. This can result in embryos that carry the same DNA within the nucleus, developing slightly different. I certainly don't understand all of this, other than to say it is impossible to ever replicate both the DNA and all of the environmental factors in the development of an embryo, and so no two will ever be exactly the same.

It would be very interesting to see this bull proven. Would he turn out to have similar Epd's to the original, or very different? At this point it appears he has had very little use. There are no daughters reported in production and no offspring ultrasounded. That surprises me. With all it must have cost to get him here, you would think some of the owners would have made an attempt to prove him. I notice the only photo is of the original Final Answer. I wonder about that also. Is there a reason they don't have a photo? I think Genex would sell more semen if they could get a half way decent photo. I also want to see a video from all sides. I personally am not willing to take a chance on a bull that I haven't at least seen a picture of.

 

[dun]

These are the split embryo clones I mentioned:
http://www.gardinerangus.com/gar_sires/ ... _3803.html
http://www.gardinerangus.com/gar_sires/ ... _3403.html

 

[Till-Hill]

Even after the clone has 1000's of progeny their epd's will never be close is my guess. Different cows, different base of epd numbers. We used to use a 5 ced as a bet the ranch calving ease bull, now we are up to more like a 15.

 

[Katpau]

dun,
Thanks for that post. Both of those bulls have similar accuracy, and both have enough offspring to give those numbers some credibility. Are you saying these two started as the exact same embryo that was split - like in identical twins? These were not just from the same flush - like fraternal twins? If so, it is fascinating to see the difference in calving ease between the two. The accuracy is still not high enough, of course, that one can be sure the difference in numbers is not just due to the luck of who they were bred to. You call them clones. Who are they a clone of? I don't see any mention of their being clones on the Registry. Still, it is interesting to look at the numbers and photos and see such a difference in identical twins if that is what they actually are.

 

[Fire Sweep Ranch]

These are the split embryo clones I mentioned:
http://www.gardinerangus.com/gar_sires/ ... _3803.html
http://www.gardinerangus.com/gar_sires/ ... _3403.html

Dun, these two bulls have two different birthdates. I doubt they are split embryo clones.

 

[dun]

These are the split embryo clones I mentioned:
http://www.gardinerangus.com/gar_sires/ ... _3803.html
http://www.gardinerangus.com/gar_sires/ ... _3403.html

Dun, these two bulls have two different birthdates. I doubt they are split embryo clones.

They are split, each one being half of the split. I don;t know what date they were put in the recip so the birthdates could be a year apart, but they are listed by ABS (old catalog from when they were active for ABS) as split embryo clones. That would be clones of each other.

 

[Katpau]

dun,
I found a link to an ad that mentions they were clones from a split embryo.
http://www.advantagecattle.com/acsassoc ... anchco.htm

 

[Fire Sweep Ranch]

These are the split embryo clones I mentioned:
http://www.gardinerangus.com/gar_sires/ ... _3803.html
http://www.gardinerangus.com/gar_sires/ ... _3403.html

Dun, these two bulls have two different birthdates. I doubt they are split embryo clones.

They are split, each one being half of the split. I don;t know what date they were put in the recip so the birthdates could be a year apart, but they are listed by ABS (old catalog from when they were active for ABS) as split embryo clones. That would be clones of each other.

So I guess my question would be were they split in a dish? We have friends that have had two sets of embryos that split in utero, which is very uncommon. These, I guess, had to be split before being put in a recip cow. I have never heard of that being done... So now I am curious.

 

[inyati13]

Kris, they have been splitting the two cell phase in a petri dish under a dissecting microscope for 30 years in the lab. I remember Dr. Spears who you are familiar with was doing that with mice in the 1970s. I don't know about cattle but the concept would be the same.

 

[dun]

So I guess my question would be were they split in a dish? We have friends that have had two sets of embryos that split in utero, which is very uncommon. These, I guess, had to be split before being put in a recip cow. I have never heard of that being done... So now I am curious.

Only makes sense if they were from different cows with different BDs that the split happened before putting them in, i.e., in a dish. Also makes ense that it wouldn;t be a true embryo but at the zygote stage.

 

[Katpau]

They were actually born only 3 days apart, so were most likely put in the recipients on the same day. I am not sure that my use of the word clone is correct for them. They would be identical twins created by splitting an embryo. The ad I showed above calls them spit embryo bothers, not clones. I thought the term clone was only used when the embryo was created by replacing the nucleus of an egg with the DNA from the animal to be cloned?

Getting back to the original question, that probably explains one reason clones are not identical to the original. They would receive most of their genetic instructions from the DNA in the nucleus from the cloned animal, but they would also receive a small amount from the mitochondrial DNA that surround that nucleus in the egg that came from a donor. Then you add to that the influence of the cow that carries that embryo in her womb, gives birth to it and raises it, and then you add other outside environmental factors such as nutrition.

 

[Rhune]

Very interesting discussion. The cloning process would take the DNA from the animal desired to be cloned and fused with an enucleated egg. The egg donor would contribute the mitochondrial DNA to the clone. This would be a difference in the clones. The original animal would have mitochondrial DNA from its mother. The nuclear DNA would be identical for all intents and purposes, only the mitochondrial DNA (and all organelles for that matter...) would be different.

I guess the follow up question is does this matter? I don't think so.

When this clone bull makes semen for breeding, he is only going to donate his nuclear DNA. The other half, and everything else will provided by the new mother.

With regard to appearance between the clone and the original: They will have completely unrelated cytoplasms. How much affect will this have on phenotypic expression of the nuclear material? I dont know, its something fun to think about, but probably little to none. Given similar environments the bulls should look essentially identical.

With regard to EPDs: The genetic coding of the sperm will be identical. Given a large enough sample size, the EPDs for both original and clone should be similar.

 

[Nesikep]

I'd like to know more about mitochondrial DNA.. I don't remember enough of it from biology 20 years ago, except it is only inherited from the dam. IIRC the mitochondria is the 'energy factory' of the cell, which makes it pretty darned important. I wonder if it would explain some of the performance differences from cows that are 15/16th sisters, differing only in a great-grand dam

 

[dun]

Very interesting discussion. The cloning process would take the DNA from the animal desired to be cloned and fused with an enucleated egg. The egg donor would contribute the mitochondrial DNA to the clone. This would be a difference in the clones. The original animal would have mitochondrial DNA from its mother. The nuclear DNA would be identical for all intents and purposes, only the mitochondrial DNA (and all organelles for that matter...) would be different.

I guess the follow up question is does this matter? I don't think so.

When this clone bull makes semen for breeding, he is only going to donate his nuclear DNA. The other half, and everything else will provided by the new mother.

With regard to appearance between the clone and the original: They will have completely unrelated cytoplasms. How much affect will this have on phenotypic expression of the nuclear material? I dont know, its something fun to think about, but probably little to none. Given similar environments the bulls should look essentially identical.

With regard to EPDs: The genetic coding of the sperm will be identical. Given a large enough sample size, the EPDs for both original and clone should be similar.

That still doesn;t explain the split embryo bulls that I posted about

 

[Son of Butch]

I would like to see real world field research done comparing contemporary calf crops of genomic young sires vs high accuracy (+94%) proven sires to see if the expected differences would hold true.
A smaller contemporary study done with a few clones vs originals would also be interesting.
But I doubt funding for such studies are available.

 

[Rhune]

Dun,

I was just rambling. Katpau's post about mDNA got my gears moving. Havent thought about genetics in awhile.

If I was to take a stab at your question.. Split embryos are genetically identical. Down to the mitochondria. Assuming the calves are truly genetically identical, the observed difference has to be environmental. Different mothers, different placental attachment/development and subsequent different nourishment during gestation. Different stresses during gestation and birth and different perinatal (is that even used with cows?) nutrition. A real geneticist would come here and probably say that the embryos are only truly identical immediately after the split. After they go off dividing on their own for a few million more times all sorts of small mutations could happen that would be accepted and encoded into the genome of the calf. I agree with this. But I dont think it would produce any noticeable difference.

Nesikep,

I was wondering the same thing. I am sure there has to be some microbiologist around here that could post something.

 

[Lucky_P]

nesikep,
You're onto something.
More and more investigation is being done looking into 'fetal programming' - and the long-term effects maternal nutrition and intrauterine environment can have on calf performance, carcass quality, health, fertility, etc.

Here's one article, for starters...
http://digitalcommons.unl.edu/cgi/viewc ... centresext

 

[dun]

nesikep,
You're onto something.
More and more investigation is being done looking into 'fetal programming' - and the long-term effects maternal nutrition and intrauterine environment can have on calf performance, carcass quality, health, fertility, etc.

Here's one article, for starters...
http://digitalcommons.unl.edu/cgi/viewc ... centresext

So what good is DNA testing or people wanting to buy a set of bulls sired by the same bull and out of half sisters?