Back to Pedigree Query
It is currently Sun Aug 09, 2020 4:19 pm

All times are UTC - 8 hours [ DST ]




Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Thu Apr 28, 2011 7:03 pm 
Offline
Allowance Winner

Joined: Wed May 11, 2005 3:49 pm
Posts: 317
Location: Northern ID
I too, as many of you may have as well, have done a lot of research on the X factor and what lines it runs through. It is so very interesting!! But, like most topics, there are always someone (s) not agreeing.

So my question is simple and on just one horse. Those that do research as well I would really like your input. I am at a bit of a disagreement so please pitch in.

One Hot Miss, great grand daughter of Secretariat on the FEMALE side. Large heart gene or not? OR, maybe possible large heart carrier, not just the gene?


Top
 Profile  
 
 Post subject:
PostPosted: Thu Apr 28, 2011 8:10 pm 
Offline
Breeder's Cup Winner

Joined: Thu Sep 16, 2004 8:46 pm
Posts: 2212
Are you referring to the 2004 gray mare? Or another mare?

If the pedigree posted for One Hot Miss 2004 gray mare is correct she doesn't have Secretariat on the dam side, but on the sire's side. Her sire is out of a Secretariat mare, just like AP Indy and Storm Cat.

Based on the posted pedigree then:

You know that Secretariat gave his X to his daughter, Triple Strike. So that makes Triple Strike Secretariat X + Unknown X

Triple Strike had a 50 50 chance of passing the Secretariat X on to her son Swing and Miss.

Whatever Swing and Miss got is what is passed on to his daughters.

Here's where it gets a bit tricky. One Hot Miss has one (Swing and Miss x) and one (Unknown X) passed on from her dam Hot Buttons.

So One Hot Miss could be showing her sire's X, one of her dam's X's or a blend of both.

If you want to track the X from the bottom side of the pedigree: multiply by .5 each generation.

Hope this helps


Top
 Profile  
 
 Post subject:
PostPosted: Thu Apr 28, 2011 8:21 pm 
Offline
Allowance Winner

Joined: Wed May 11, 2005 3:49 pm
Posts: 317
Location: Northern ID
Sorry, I was referring to Swing And Miss coming off the female side of Secretariat. That is what I meant by the female side. Sometimes I think people know what I am thinking.

There is just so much controversy to where some say that sex is not a factor at all, referring to Mr. Prospector.

I feel this mare would carry the gene based on her top side if you believe what is said.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 29, 2011 9:35 am 
Offline
Breeder's Cup Winner

Joined: Thu Sep 16, 2004 8:46 pm
Posts: 2212
What are folks saying about Mr. Prospector in relation to the X factor?

Did Swing and Miss look like Secretariat? What was his race record, did he sire better daughters than sons? All of these will give you some indication if Swing and Miss did get the Secretariat X. If he didn't get that X he can't pass it on to the next generation.


Top
 Profile  
 
PostPosted: Fri Apr 29, 2011 10:40 am 
Offline
Allowance Winner

Joined: Mon Mar 21, 2005 12:50 pm
Posts: 451
Location: Lexington, Kentucky
oleos93 wrote:
I too, as many of you may have as well, have done a lot of research on the X factor and what lines it runs through. It is so very interesting!! But, like most topics, there are always someone (s) not agreeing.

So my question is simple and on just one horse. Those that do research as well I would really like your input. I am at a bit of a disagreement so please pitch in.

One Hot Miss, great grand daughter of Secretariat on the FEMALE side. Large heart gene or not? OR, maybe possible large heart carrier, not just the gene?


Oleos93,

The horse has been selectively bred over 300 years so the theory that there is a single gene located on the X chromosome that is controlling heart size and its subsequent relation to performance is misleading at least. If is was something as easy as it was put in Marianna Haun's books, we would have been selecting for this, either by design or happenstance, for such a long time that all horses would have the gene and therefore it would have little relevance.

Geneticists who are working on thoroughbred performance are of the opinion that performance will be measured by a large number of genes located on the nuclear and quite possible mtDNA with each having an additive effect (a polygenic profile). They have not found any evidence of these performance variants being located on the X chromosome.

While it is interesting to look at, I am afraid to say on current scientific evidence, the X factor is a very misleading theory.

_________________
Byron Rogers
Performance Genetics
http://performancegenetics.com
Keen Ice...Verrazano...Fontiton...Divisidero...Breaking Lucky...Hoss Amor...


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 29, 2011 11:30 am 
Offline
Grade I Winner
User avatar

Joined: Wed Jul 04, 2007 8:49 pm
Posts: 1713
Location: Virginia
So I have a question... Are you then saying that if an athlete does actually possess a larger than average heart that it would be of little consequence in his/her performance?
I think the theory behind X-factor is a tad basic but I believe the principles of the mechanics do hold water. Can it be so easily traced horse to horse in a pedigree, I wouldn't think completely so.
Not to mention if I really wanted to know if my horse possessed the larger heart I think I would just get an echocardiogram.

_________________
trying to come up with something brillant..... this may take a while. :)


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 29, 2011 6:36 pm 
Offline
Allowance Winner

Joined: Wed May 11, 2005 3:49 pm
Posts: 317
Location: Northern ID
Had to go find this as I did not want to try and quote it on my own. I think this person is trying to say that the "therory" is not always correct:


To illustrate using the normal hearted Mr Prospector (h). He should have inherited a large heart from his dam Gold Digger who was a daughter of the large hearted Nashua (H) and the double copy mare Sequence (HH) if the factor responsible for heart size is carried on the X chromosome. It is possible that Sequence has been wrongly classified and she was in fact only a single copy mare. This in turn means that Count Fleet must have been normal hearted or Miss Dogwood was a single copy mare (Hh) or possibly even (hh). However, if we assume that Sequence has been correctly classified the normal hearted Mr Prospector can be explained if this is a non-sex linked trait. It would also explain why Mr Prospector could be an outstanding sire but with a tendency for his offspring to excel over shorter distances yet still produce stock that can get a trip. There is plenty of evidence that heart size is increasingly important as distance increases. If it were a non-sex linked characteristic Mr Prospector would have inherited an H gene from Gold Digger and h gene from Raise A Native (he in turn would be Hh or hh for heart size). This means Mr Prospector would be heterozygous for heart size (Hh) even though his dam Gold Digger was homozygous (HH) for this trait.

That the trait is not sex-linked makes it easier to explain apparent exceptions to the X Factor rather than saying that some large hearted horses may have been wrongly classified or some other factor is involved that switches the gene on or off. No further explanation is necessary if the gene or genes responsible are on a non-sex linked chromosome. If it is a dominant trait then when two homozygous (HH) carries mate, the trait will be expressed in all offspring. If two heterozygous carriers mate (Hh) then one in four offspring will display the trait. If two homozygous (hh) carriers mate the trait will never be expressed in the offspring. More research is needed.


Top
 Profile  
 
 Post subject:
PostPosted: Fri Apr 29, 2011 6:54 pm 
Offline
Allowance Winner

Joined: Wed May 11, 2005 3:49 pm
Posts: 317
Location: Northern ID
xfactor fan,

From what I see in Swing and Miss the majority of winners are the males, BUT and you have to agree with me here, most breeders/owners and trainers rather race a colt over a filly anyway, as the industry has told us that they are more competitive. I do not agree but it is what it is. When looking at his offspring, VERY VERY few fillies made it to the track at all so never got a chance. I think that happens a lot in the world of horses in general. So how do we really know for sure?

You would think after so many great fillies and mares are becoming more and more acknowledged that we as an industry would stop throwing them away.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 30, 2011 12:33 pm 
Offline
Breeder's Cup Winner

Joined: Thu Sep 16, 2004 8:46 pm
Posts: 2212
First I'd like to make it clear that the theory as Ms Haun presents it has some holes. Not in the science per say, but the way the science is presented. She's not a good science writer.

Going from fact:

There is a range in heart size present in the TB, and in the Arabian breed. I'd be very interested to see research on the Turkoman breeds, but haven't seen anything one way or the other.

As an interesting side note, greyhound dogs also show a the same type of variation in heart size. Interesting that this is showing up in another species also selected for running.

Heart size is going to be under genetic control--unless you believe it is strictly environmental.

So here are the choices:

mtDNA--which would show a pattern of showing inheritance in female families. All the sons and daughters of Somethingroyal would have the large heart, and the sons wouldn't pass it on, but the daughters would.

Autosomal--- Models of inheritance would be like the gray coat color--Dominant, 50% or 100% would have the trait. Recessive like the chestnut gene takes two copies to produce make the color.

Sex Linked ----Trait carried on the X chromosome. The Y is very small and there isn't much variation between Y's in all the horse breeds.
Females would pass it on to sons, who would in turn pass it on to their daughters. Sons would not pass it on to their own sons.

Pseudo Sex Linked-- Autosomal but only works when passed on via one sex parent.

Of the choices for the large heart, the two that fit best are the last two--Sex linked, or Pseudo Sex linked.

One of the problems with how the theory is applied, is that folks decide --without proof---that such and so horse must have the trait, or in the case of mares, they have either one copy or two. While you can weigh or measure the heart in stallions, and know the size of the heart. This option isn't as clear with the mares.

How the X is expressed in females is different than the males. Each female cell has only one functioning X, the other is turned off very early in embryonic development. (Between fertilization and implantation)
The question of how this plays out via the X factor theory has never been addressed.
Is this an either or scenario? or is there a blending of heart sizes?

As for the Mr Prospector question. Did anyone measure his heart either before or after he died? Did he have a large heart or normal heart?

Again, look at the facts. Mr Prospector was a short sprinter, very speedy over short distances. Sired lots of very good sons. Both of these are signs of a normal heart size. --Not proof, but indications.

Using Mr Prospector to disprove the theory is based on the assumption that his dam Gold Digger carried two copies of the large heart gene.

Taking a look at Gold Digger's produce record doesn't shout double copy.

Again, folks are making assumptions about the genetic status of horses going back four generations. And some of those assumptions seem to have a lot of wishful thinking.

brogers. I don't think it is as simple as presented in the X factor books, however there is a chance that there is a region that controls heart size, were there is a "mistake" and some genetic information is copied multiple times, leading to increased heart size.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 30, 2011 3:07 pm 
Offline
Grade III Winner
User avatar

Joined: Fri Dec 01, 2006 10:36 pm
Posts: 1150
Location: New England & Florida
If I understand it correctly Marianna Haun argues that heart size is exclusively the domain of the X and therefore the actual heart size of a stallion can have no bearing on the size of the heart of any of his sons.

The heart of Risen Star, Secretariat's Belmont-winning, champion son, was viewed by someone before his parts were buried who reported that "it was massive, as big as a soccer ball". So to explain its size, according to Haun, we're supposed to completely discount Secretariat's own magnificent heart and look for X suspects in the pedigree of Risen Star's dam?

That seems to me not only too simple, but scientifically downright simple minded..

Allison

_________________
"He is pure air and fire and the dull elements of earth and water never appear in him; he is indeed a horse ..." Wm. Shakespeare - Henry V


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 30, 2011 4:18 pm 
Offline
Breeder's Cup Winner

Joined: Thu Sep 16, 2004 8:46 pm
Posts: 2212
Yes, that's how the X is supposed to be transmitted.

The thing to look at, is how many other sons of Secretariat had large hearts? How many paternal grandsons? How many maternal grandsons?

Again here's the problem, someone looked at Risen Star's heart and said it was large. Was it weighed? Did this someone have the experience to know a large heart from a small one? Was it a large healthy heart, or a unhealthy enlarged heart?

Good science is like putting together a good court case, there needs to be lots of verifiable solid evidence, not speculation.


Top
 Profile  
 
 Post subject:
PostPosted: Sat Apr 30, 2011 5:23 pm 
Offline
Grade III Winner
User avatar

Joined: Fri Dec 01, 2006 10:36 pm
Posts: 1150
Location: New England & Florida
Risen Star's heart size was reported by Frances J. Karon who I believe has the experience and credentials to be trusted.

Here's the link: http://runroughshod.blogspot.com/2011_0 ... chive.html

_________________
"He is pure air and fire and the dull elements of earth and water never appear in him; he is indeed a horse ..." Wm. Shakespeare - Henry V


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 01, 2011 1:56 am 
Offline
Breeder's Cup Winner

Joined: Thu Sep 16, 2004 8:46 pm
Posts: 2212
I asked to see at Risen Star one last time before he was buried. Maybe it was a strange or morbid request but I just wanted to have a look. His heart – and I couldn’t tell you what it weighed or how it compared in size to other equine hearts – was massive; the engine that powered Risen Star was as big as a soccer ball. Now, every time I watch a replay of the 1988 Belmont, in my mind I see this perfect engine driving him home.


Here's the quote from the very nice piece by Frances J. Karon.

Yes, an experienced observer, but admits that "I couldn’t tell you what it weighed or how it compared in size to other equine hearts"

I'm willing to believe that Risen Star had a large heart. But I'd be a lot happier if someone had weighed the heart , or the vet doing the necropsy had given an estimate, both of the size and the state of health.

My point is not if Risen Star had a large heart or not, but that this issue is only going to be solved by the application of good science.


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 01, 2011 4:30 am 
Offline
Grade III Winner
User avatar

Joined: Fri Dec 01, 2006 10:36 pm
Posts: 1150
Location: New England & Florida
Like you "I'm willing to believe that Risen Star had a large heart."

Absent the science that proves otherwise, I just find it difficult to believe that his sire, Secretariat, would have had absolutely nothing to do with it.

_________________
"He is pure air and fire and the dull elements of earth and water never appear in him; he is indeed a horse ..." Wm. Shakespeare - Henry V


Top
 Profile  
 
 Post subject:
PostPosted: Sun May 01, 2011 8:54 am 
Offline
Breeder's Cup Winner

Joined: Thu Sep 16, 2004 8:46 pm
Posts: 2212
One of the questions asked earlier in this thread is why the large heart hasn't been bred for.

The discussion about Risen Star is a perfect example of the problem. Large heart stallion sires large heart son. Must be related. Must come down from the top side of the pedigree.

Folks don't even want to consider it might come from the bottom side, or be related to mtDNA interacting with DNA on the chromosomes, or pseudo-sex linked. Or something that won't be discovered for another decade.

IF it is sex linked, then you can breed to a large heart stallion, and unless the females carry the large heart, you aren't going to get large heart colts. And if the large heart contributes to the racing success of the stallion, then the normal heart size colts will not approach the quality of the sire.

But no one in the breeding game is going to admit that their champion racehorse stud is going to be a dud. There is way to much money involved. I'm not suggesting there is a conspiracy--just that there are economic factors in play that don't want to look at the science.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 26 posts ]  Go to page 1, 2  Next

All times are UTC - 8 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group