Genetic Tests For Thoroughbreds

[Patuxet]

A horse genomics researcher and an Irish racehorse trainer have co-founded a company to provide genetic tests for Thoroughbreds: http://bit.ly/4o6HP2

[Pan Zareta]

Interesting. Most of Dr. Hill's published equine research was on mtDNA. She was the lead author of the first (2002) of two mtDNA studies of the TB (underwritten by Godolphin). The authors of the second study (2006) commercialized their research prior to publication in the form of Thoroughbred Genetics. A review of published findings re. mtDNA in other horse breeds and TB sequences in GenBank yields compelling evidence against the conclusion (2002) that seven of the Lowe-numbered TB female families may share a founder in the ~1650-1750 time frame. A similar review suggests that the study for the 2006 report didn't distinguish between sub-groups within the most common (in the TB) mtDNA haplogroup. (In fairness, if they had made that distinction the commercial value of their work would have diminished. It would have been obvious, from correlation of haplotypes and family #'s reported 2002, which families have demonstrated better aptitude for a particular distance.)

As the dau. of a university faculty member I can certainly appreciate why academic researchers want to enjoy more commercial benefit from their work than has historically been the case. But I'm not sure the academic to corporate crossover is always to the greater overall good. Equinome is not going to share their findings re. the genetics of equine athletic performance traits, nor should they. But in the course of their analyses, they're likely to identify genetic factors predictive of inherent unsoundness. Those findings, imho, should be shared (published), but they probably won't be unless doing so is commercially neutral.

[brogers]

Apparently Equinome and the Equinome Speed Gene Test on Friday 29th January, and the scientific manuscript describing the finding will be published in advance of that.

[Pan Zareta]

and the scientific manuscript describing the finding will be published in advance of that.

An update or supplement to the article published at PLoS last June ('A Genome Scan for Positive Selection in Thoroughbred Horses')?

[Patuxet]

John Sparkman picked up on this in his blog under the title "The future is now?" and Byron Rogers added information in one of the comments.

http://pedigreecurmudgeon.blogspot.com/ ... l#comments

[Patuxet]

The study on the relationship of specific gene alleles to maximum win distance has been published and John Sparkman summarized it thusly:

"Briefly, the research shows that there are two alleles, "C" and "T", at a particular position on a gene that governs muscle mass in Thoroughbreds. This means the horse's genetic code at that particular spot must read either "CC", "CT" or "TT". The important finding from the research on populations of both elite and non-elite Thoroughbreds is that CC horses strongly prefer sprint distances and are more precocious, CTs are mostly milers and 10-furlong horses who may or may not be precocious, and TTs are mostly 10-furlong and up horses.

The distributions of the genes are about the same in the elite and non-elite groups, so Equinome does not claim to test for the class of the animal, just the distance capacity."

In a discussion of this subject on another forum someone posted the following. I was unaware of the whippet study.

"People should be careful how to use this knowledge in breeding decisions. Partly because genes are often tied to multiple traits, deliberate selection of certain genes can backfire. In 2007, a scientist at the U.S. National Institutes of Health (NIH) found that the fastest whippets had a single mutated copy of a speed- and strength-related gene. In contrast, whippets who had a double copy, because both parents were very fast due to a single copy, were ugly, heavy-set, and muscle-bound."

[Pan Zareta]

Thanks Patuxet!

Here's the link to the newly published study - A Sequence Polymorphism in MSTN Predicts Sprinting Ability and Racing Stamina in Thoroughbred Horses.

[vineyridge]

PZ, the link doesn't work for me. PLoS can't find the article.

[Pan Zareta]

Thanks Viney - it should be working now.

[vineyridge]

Thanks Viney - it should be working now.

WOW! That's the only thing that comes to mind.

WOW!

[xfactor fan]

This sure looks like the genetic basis of the old breeding theory "Breed long horses to short horses to get classic horses" .

[Dave C]

And now the argument can start about where the 'C' allele came from. Is this a mutation that Phalaris introduced to the TB's? Is it an older variant that has always been present and only started to dominate in the 20th century? Questions and more questions.

[Pan Zareta]

And now the argument can start about where the 'C' allele came from. Is this a mutation that Phalaris introduced to the TB's? Is it an older variant that has always been present and only started to dominate in the 20th century? Questions and more questions.

I sense some tongue-in-cheek there. But lest anyone of the 'blame Phalaris' persuasion seize that notion and run with it, be advised that this SNP is not unique to the TB. Arabs & QH were also checked. The former is disproportionately T/T. The latter is disproportionately C/C. Surprise, surprise......

(ETA: that should say Egyptian Arabs...were also checked.)

[xfactor fan]

What you want to bet the Hobby was where the CC came from?

[Pan Zareta]

What you want to bet the Hobby was where the CC came from?

The Hobby may well have been disproportionately C/C homozygotes. But even under selection pressure heterozygotes (C/T) as well as homozygotes (C/C or T/T) will occur within any population that sustains both alleles. Among 35 QH's sampled, 5 were C/T, 1 was T/T.