X factor and large heart
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X factor and large heart
Has the X Factor theory proposed by Marianna Haun been proven false?
- Pan Zareta
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It was never proven true to begin with.
All members of the Horse Genome project that are active in TB research have dismissed the notion of a gene or genes controlling heart size on the X. It's one of the several popular but genetically groundless breeding theories discussed in Binns and Morris' Thoroughbred Breeding: Pedigree Theories and the Science of Genetics. Matthew Binns was one of the geneticists on the Horse Genome project. Tony Morris writes for Racing Post. When asked about it, he often sums up the X Factor theory accurately and succinctly as "rubbish".
All members of the Horse Genome project that are active in TB research have dismissed the notion of a gene or genes controlling heart size on the X. It's one of the several popular but genetically groundless breeding theories discussed in Binns and Morris' Thoroughbred Breeding: Pedigree Theories and the Science of Genetics. Matthew Binns was one of the geneticists on the Horse Genome project. Tony Morris writes for Racing Post. When asked about it, he often sums up the X Factor theory accurately and succinctly as "rubbish".
X factor theory
Pan Zareta: You feel that the X factor theory proposed by Marianna Haun is rubbish. The woman wrote three books regarding the X factor theory and much of the material in her three books is evidence to support the theory. A theory will stand as a theory until evidence proves it wrong. So far, genomic research has not proven the theory wrong. Just because they have not yet found a gene or genes on the X chromosome that relates to heart size/function does not mean they do not exist.
Have genomic researchers ever found a gene on autosomes that relate to heart size/function?
The Pedigree query site sells X factor information to its subscribers. Tell them that the theory is rubbish.
Have genomic researchers ever found a gene on autosomes that relate to heart size/function?
The Pedigree query site sells X factor information to its subscribers. Tell them that the theory is rubbish.
- Pan Zareta
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Re: X factor theory
stancaris wrote:Pan Zareta: You feel that the X factor theory proposed by Marianna Haun is rubbish. The woman wrote three books regarding the X factor theory and much of the material in her three books is evidence to support the theory. A theory will stand as a theory until evidence proves it wrong. So far, genomic research has not proven the theory wrong. Just because they have not yet found a gene or genes on the X chromosome that relates to heart size/function does not mean they do not exist.
Have genomic researchers ever found a gene on autosomes that relate to heart size/function?
Number of books written/published has no bearing on the validity of Haun's hypothesis which holds that heart size is primarily controlled on the equine X chromosome and that there are more and less desirable variants of the controlling gene/genes. As you were first informed nearly two years ago by a highly credible source, and have been reminded many times since, the variants on the X have been identified and none of them have anything to do with heart size. The same source also told you that "[t]here are variations that are found in large/effective hearted horses that are not on the X Chromosome". That is consistent with public and private reports from other parties studying the TB genome. Haun's hypothesis was wrong.
The Pedigree query site sells X factor information to its subscribers. Tell them that the theory is rubbish.
When asked, I didn't use the word "rubbish" though I did tell one of the site owners that while the X factor hypothesis has been proven false it will probably be a matter of years before that fact is fully assimilated and until that time some percentage of their db subscribers will undoubtedly expect continued support for that optional feature. Don't confuse the desire to appeal to the widest possible client base with endorsement of Haun's false hypothesis.
proof
Pan Zareta quoted a highly credible source as follows: "there are variations that are found in large/effective hearted horses that are not on the X Chromosome". And that from this quote you conclude that Haun's hypothesis is wrong.
That quote in NO WAY proves Haun's hypothesis is wrong. All that quote does is state that there are variations found in large hearted horses that are not on the X Chromosome. That quote does not state that there are variations on other chromosomes that relate to heart size/function.
That quote in NO WAY proves Haun's hypothesis is wrong. All that quote does is state that there are variations found in large hearted horses that are not on the X Chromosome. That quote does not state that there are variations on other chromosomes that relate to heart size/function.
- Pan Zareta
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Re: proof
stancaris wrote:That quote in NO WAY proves Haun's hypothesis is wrong. All that quote does is state that there are variations found in large hearted horses that are not on the X Chromosome. That quote does not state that there are variations on other chromosomes that relate to heart size/function.
Those remarks make no sense whatsoever. The fact that none of the variants on the X have anything to do with heart size/form/function is what proves Haun's hypothesis false. The quote was intended to address this question -
stancaris wrote:Have genomic researchers ever found a gene on autosomes that relate to heart size/function?
The answer is, obviously YES. If they've found "variations that are found in large/effective hearted horses that are not on the X" then where do you think those variants are if not on the autosomes? Somewhere in outer space? You were also informed of the specifics, in terms of autosome #, of where one of those variants is found.
- Pan Zareta
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Re: HERE
stancaris wrote:Could you state the reference where posters reading this thread can actually see evidence that variants on autosome # whatever is actually related to heart size?
As posted 21 Nov 2011 page 12 The Mares in Great Sires thread.
*Emphasis supplied to last sentence of quoted text is my own.*
brogers wrote:stancaris wrote:Byron
You said your company has not not done a complete scan of all the genes on the x chromosome. Then how can you be sure that the X chromosome does not carry a gene or genes for heart development?
Since the gene or genes for heart size has not yet been discovered, your statement that the x chromosome does not carry that gene is certainly a hasty conclusion. Until geneticists find a gene that dictates a large heart on another chromosome, one can not say the x chromosome is not responsible for heart size. Just because it hasn't been found does not necessarily mean it does not exist.
Stan,
We used the 70KSNP chip that has 'markers' on the X chromosome. When we tested horses with different cardio capacities against one another we didn't find a variation in the genetic code between the groups that reached statistical significance. To say that "gene or genes for heart size has not yet been discovered " is wrong. They have been and they are not located on the X.
Here is one (it is not just one gene either).
http://www.ncbi.nlm.nih.gov/projects/ma ... 2146342406)&QSTR=NAB1
and this is what it does
http://www.wikigenes.org/e/ref/e/16025126.html
It is located on Chromosome 18, right near Myostatin which also is an important gene for performance.
Obviously you have vested a lot of time and effort into preaching the "X factor" so it is hard to believe that what was printed is not reality, but it is what it is.
In reply to this you predictably tried to misrepresent NAB1 as irrelevant to healthy heart size in TBs. That's bogus. NAB1's role in healthy cardiac muscle growth is well documented in the equine and other species. Its variants are catalogued in the EquCab2 SNP database.
healthy heart size
Pan Zareta: The function of the NAB1 gene from above seems to be only in relation to pathological hearts.
Could you point out any genomic studies that point out NAB1's role in healthy cardiac growth in the horse? I am not trying to misrepresent NAB1's role in the horse. I would just like to see evidence that NAB1 is a variant on an autosome that is directly related to healthy cardiac muscle growth in the horse.
Could you point out any genomic studies that point out NAB1's role in healthy cardiac growth in the horse? I am not trying to misrepresent NAB1's role in the horse. I would just like to see evidence that NAB1 is a variant on an autosome that is directly related to healthy cardiac muscle growth in the horse.
- Pan Zareta
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Re: healthy heart size
stancaris wrote:Pan Zareta: The function of the NAB1 gene from above seems to be only in relation to pathological hearts.
No, Stan, it isn't. As you were informed the last time you made that claim about NAB1, it is a regulator of cardiac growth of any variety. Buitrago et al. 2005 documented as much when quantifying and qualifying its expression in pathological cardiac hypertrophy "we describe the transcriptional repressor NAB1 as an endogenous regulator of cardiac growth....NAB1 is highly expressed in mammalian cardiac myoctyes and it inhibited cardiomyocyte hypertrophy through repression of its targets, transcription factor EGR..." etc.