Forgive me for posting twice to different boards, one of the members with more experience suggested I would get more viewers on this board. So here's hoping.
I am a mature university student in UK. My current project involves the use of X Factor data from this Thoroughbred database. It would be very helpful if someone with responsibility for the database could give me an explanation of the provenance, veracity and methodology used to create the single and double copy X factor lines down the female side.
For instance, are they based on a list of single and double copy mares originating from Marianna Haun (or someone else) or do they all emanate from Eclipse (looking at the database it appears not). I suspect some other method is used but have not been able to infer what it is. I'd appreciate your help.
Thanks
Seabird
X-Factor methodology
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xfactor fan
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I'm a cheapie, and don't pay for the service, so the x-factor feature doesn't work.
However, from what I've seen, there seems to be a whole lot of claims that aren't backed up by any real info. It would be great if there was a field to enter heart scores in the database.
Also any good stallions seems to be presumed to have a large heart score which is also not true.
I'd take any claim of double copy mares with a great deal of caution and want to have heart scores to back up the claim.
Sorry, couldn't help more.
However, from what I've seen, there seems to be a whole lot of claims that aren't backed up by any real info. It would be great if there was a field to enter heart scores in the database.
Also any good stallions seems to be presumed to have a large heart score which is also not true.
I'd take any claim of double copy mares with a great deal of caution and want to have heart scores to back up the claim.
Sorry, couldn't help more.
Thanks for your input Xfactor Fan, your caution is understandable.
As you say, when entering a new horse into the database there is no field to enter heart score, as a consequence some method must be being used to decide that what has just been entered is going to show as a single, double or no X-linked offspribng.
In the absence of any definitive answer to my query, as yet, does anyone know who the owner(s) of the Pedigree Online Thoroughbred Database are? Perhaps I could contact them directly for an answer.
As you say, when entering a new horse into the database there is no field to enter heart score, as a consequence some method must be being used to decide that what has just been entered is going to show as a single, double or no X-linked offspribng.
In the absence of any definitive answer to my query, as yet, does anyone know who the owner(s) of the Pedigree Online Thoroughbred Database are? Perhaps I could contact them directly for an answer.
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yukidragon
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I have the ability to 'turn on' the x-factor on a horse's pedigree - but alas, I know absolutely nothing about the subject. 
You can show me hearts scores all day, and I'll just blink at them.
However, if you know a horse that should definitely be marked as a carrier, but is not (or one that is and shouldn't be), feel free to PM me.
You can show me hearts scores all day, and I'll just blink at them.
However, if you know a horse that should definitely be marked as a carrier, but is not (or one that is and shouldn't be), feel free to PM me.
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xfactor fan
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Lucy, here's the theory.
Fact: Horses have hearts that vary in size. TB's have larger hearts the the average run of horses. Most run about 8-9 lbs.
Secretariat had a perfect 20-22 lb heart. There is a positive conection between heart size and increased cardio.
The theory is that the gene/gene complex for the heart size lives on the equine X chromosome. This is one of the two sex chromosomes. Stallions are XY, Mares XX,
a stallion with only one X will always express what ever is on the X he got from his Moma. Mares with two XX, will either express one X or a combination of both X's.
So a Stallion that is a large heart stallion will give his X to his daughters. His sons will have the X from their dams.
The theory is that having a large heart will boost racing performance up to 25%. So the daughters of a large heart stallion will have a chance to express the large heart and may perform at the same racing level as their sire.
Colts get the Y, and the X from their dams, and so unless the mares contribute a large heart X, the colts will perform 25% less than their sires.
Secretariat is the poster boy for the X factor theory, and ALL of his daughters will carry his large heart X.
Known large heart stallions:
Secretariat
Key to the Mint
War Admiral
Princequillo
Large heart scores are better than small heart scores, and these are obtained by hooking the horse up the the equine version of an EKG. This is better than waiting till the horse dies and the weighing the heart at the necropsy.
Single copy mares have one verified copy of a large heart X, and one normal size heart x. Double copy mares have two large heart X's.
Just because a mare has a large heart X, doesn't mean that she will pass it on to her foals.
There's more, but this is the basic theory.
Not everyone thinks that the large heart gene is on the X. Some folks believe that it is one one of the autosomal chromosomes ( Non sex linked) so it would be passed on like the gray gene.
Hope this helps to understand the X factor feature built into the database.
Fact: Horses have hearts that vary in size. TB's have larger hearts the the average run of horses. Most run about 8-9 lbs.
Secretariat had a perfect 20-22 lb heart. There is a positive conection between heart size and increased cardio.
The theory is that the gene/gene complex for the heart size lives on the equine X chromosome. This is one of the two sex chromosomes. Stallions are XY, Mares XX,
a stallion with only one X will always express what ever is on the X he got from his Moma. Mares with two XX, will either express one X or a combination of both X's.
So a Stallion that is a large heart stallion will give his X to his daughters. His sons will have the X from their dams.
The theory is that having a large heart will boost racing performance up to 25%. So the daughters of a large heart stallion will have a chance to express the large heart and may perform at the same racing level as their sire.
Colts get the Y, and the X from their dams, and so unless the mares contribute a large heart X, the colts will perform 25% less than their sires.
Secretariat is the poster boy for the X factor theory, and ALL of his daughters will carry his large heart X.
Known large heart stallions:
Secretariat
Key to the Mint
War Admiral
Princequillo
Large heart scores are better than small heart scores, and these are obtained by hooking the horse up the the equine version of an EKG. This is better than waiting till the horse dies and the weighing the heart at the necropsy.
Single copy mares have one verified copy of a large heart X, and one normal size heart x. Double copy mares have two large heart X's.
Just because a mare has a large heart X, doesn't mean that she will pass it on to her foals.
There's more, but this is the basic theory.
Not everyone thinks that the large heart gene is on the X. Some folks believe that it is one one of the autosomal chromosomes ( Non sex linked) so it would be passed on like the gray gene.
Hope this helps to understand the X factor feature built into the database.
Sorry, I didn't explain myself very well.
I subscribe to the database so I can see the X-Factor horses if I switch the flag on. But how can I verify the information? With Dosage, for example, I can calculate a Dosage profile for myself because how Dosage is made up is published by Dr Steve Roman. Similarly, Conduit Mare Profile can be checked because Bill Lathrop publishes his methodology.
Unless we know that the database shows blue and red lines for large-capacity heart stallions and mares down the female side because they are derived from:
a) information already published by Marianna Haun, for example, her list(s) of double copy mares.
b) Ancestral autopsy data such as Secretariat, Eclipse, Phar Lap etc.
c) Heart scores (although the correlation of heart score as originated by Dr James D Steel and heart size has been challenged in a more recent study - send me a private message if you want the paper citation)
or
d) some other method
we cannot do sample verification of the data.
As a researcher I need to know what level of trust to apply to data I am using then I can record that in my findings and conclude accordingly.
I hope this is a better explanation of why I was asking the question.
I subscribe to the database so I can see the X-Factor horses if I switch the flag on. But how can I verify the information? With Dosage, for example, I can calculate a Dosage profile for myself because how Dosage is made up is published by Dr Steve Roman. Similarly, Conduit Mare Profile can be checked because Bill Lathrop publishes his methodology.
Unless we know that the database shows blue and red lines for large-capacity heart stallions and mares down the female side because they are derived from:
a) information already published by Marianna Haun, for example, her list(s) of double copy mares.
b) Ancestral autopsy data such as Secretariat, Eclipse, Phar Lap etc.
c) Heart scores (although the correlation of heart score as originated by Dr James D Steel and heart size has been challenged in a more recent study - send me a private message if you want the paper citation)
or
d) some other method
we cannot do sample verification of the data.
As a researcher I need to know what level of trust to apply to data I am using then I can record that in my findings and conclude accordingly.
I hope this is a better explanation of why I was asking the question.
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xfactor fan
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Trust nothing published on the database. It is open to anyone who wants to post any information. And there has been an ongoing battle with folks who change data, change ownership, and in general muck up the data.
Hauns data such that it is also has problems. There were a couple of published studies mentioned in the first of Hauns books. You might want to start with the folks who have done real science on the topic.
Hauns data such that it is also has problems. There were a couple of published studies mentioned in the first of Hauns books. You might want to start with the folks who have done real science on the topic.
Actually, X-Factor is one thing the public can not alter. Only the boys in charge, or the research group, can add a carrier.
However, I do not know who initially activated the horses currently in here. I would imagine they'd have worked from Haun's list (heck, even i've heard of that ), but don't know for sure, and do not know how they confirm any suggested additions to the list.
Thank you for all the info.
However, I do not know who initially activated the horses currently in here. I would imagine they'd have worked from Haun's list (heck, even i've heard of that
), but don't know for sure, and do not know how they confirm any suggested additions to the list.
Thank you for all the info.
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xfactor fan
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angelsprite
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Seabird,
I assume you are doing research for a school related project. If so, be very cautious about what you accept as fact with regard to the X-Factor hypothesis. The veterinarian who performed the autopsy on Secretariat has said that the heart was not weighed. He guessed it's weight. Secondly, hearts can and often do enlarge post-mortem. Heart size and development is a polygenic inheritance trait. The lady who wrote the book on X-Factor hypothesis is not a geneticist, but a staff writer for the Thoroughbred Times who was great friends with the owners of Secretariat and her book was instrumental in drawing attention to his bloodline, which gave it a much needed shot in the arm. This translates into money for all concerned. The pedigree query site is wonderful and very useful, but there are occasional errors in pedigrees. It is unavoidable, I'm sure, with so many people editing and so many similar horse names from different breeds. Corrections are usually possible by searching other sites for pedigree information or sale pages. Always remember, the scientific definition of a "theory" is "that which we are most certain of." A theory has been tested in repeatable experiments and found to be true each time. So, good luck in your X-factor research. Maybe the hypothesis will finally get the testing in repeatable experiments that it needs.
I assume you are doing research for a school related project. If so, be very cautious about what you accept as fact with regard to the X-Factor hypothesis. The veterinarian who performed the autopsy on Secretariat has said that the heart was not weighed. He guessed it's weight. Secondly, hearts can and often do enlarge post-mortem. Heart size and development is a polygenic inheritance trait. The lady who wrote the book on X-Factor hypothesis is not a geneticist, but a staff writer for the Thoroughbred Times who was great friends with the owners of Secretariat and her book was instrumental in drawing attention to his bloodline, which gave it a much needed shot in the arm. This translates into money for all concerned. The pedigree query site is wonderful and very useful, but there are occasional errors in pedigrees. It is unavoidable, I'm sure, with so many people editing and so many similar horse names from different breeds. Corrections are usually possible by searching other sites for pedigree information or sale pages. Always remember, the scientific definition of a "theory" is "that which we are most certain of." A theory has been tested in repeatable experiments and found to be true each time. So, good luck in your X-factor research. Maybe the hypothesis will finally get the testing in repeatable experiments that it needs.
Derring
The red lines represent single copy mares and the blue ones double copy mares. The theory is that a double copy mare is certain to pass on the large heart gene to a colt and to a filly IF the sire also has a large-heart X chromosome. If the sire does not have the large heart then the large heart from the dam may or may not be passed to the filly. Consequently a red single copy line stops when it cannot be inferred that the large heart continues and a blue line can become a red line when the sire is not passing on a large heart on his X to a daughter.
I hope that is clear.
Seabird
The red lines represent single copy mares and the blue ones double copy mares. The theory is that a double copy mare is certain to pass on the large heart gene to a colt and to a filly IF the sire also has a large-heart X chromosome. If the sire does not have the large heart then the large heart from the dam may or may not be passed to the filly. Consequently a red single copy line stops when it cannot be inferred that the large heart continues and a blue line can become a red line when the sire is not passing on a large heart on his X to a daughter.
I hope that is clear.
Seabird