The Y-chromosome in English Thoroughbred racing stock

Just came across an interesting article from 2005 in the New Scientist: Irish researchers analyzing Y-chromosome sequences in the DNA of a sample representative of the 500,000 or so English Thoroughbred racehorses alive today found that 95% of these horses traced to a single horse in the tail male: the Darley Arabian, born in 1700 (who by the way, was a Ma’naghi from the Fad’aan Bedouin tribe, which makes this strain one of the oldest recorded).

I wonder how many different sire lines a similar study could identify within the Arabian horse population…

8 Replies to “The Y-chromosome in English Thoroughbred racing stock”

  1. Very true ,this study was made by researchers of ” The Trinity College” in Dublin in 2003.After that I wrote an article on the “Darley Arabian”
    naming him “Malak el Kheil” (King of Horses).
    This study shows that the supposed 2 other founders of the thouroughbred race(Godolphin and Byerley)where from inferior origin or even not pure Arabs.
    In fact there was a lot of other Arab stallions imported to England at that time.

  2. I hope so, anyway i will scan it and send it to you to post it as I can post or send any an image trough “word press”

  3. To the best of my knowledge there is still no report of Y chromosome DNA variation in the horse. It is at least clear, because variation has been so much harder to find than it is in, say, dogs or humans, that the domestic horse shows less Y chromosome variation than other species. This is an extremely interesting observation, but it does mean there’s no way so far to compare pedigree records with biological data the way we’ve done with mitochondrial DNA and dam lines.

    It’s a matter of stud book record, though, that the vast majority of TBs descend in male line from the Darley Arabian. It’s a defined statistical phenomenon (well enough established that it’s known as the surname problem) that, given sufficient number of generations, any population will reduce to a single male line. One can picture that the effect is heightened by the TB population structure, where a few elite sires have dominated each generation for a few hundred years now.

  4. Hi Michael, you mean one could have reached the same conclusion by studying the males lines of English TBs in the world studbooks, right?

  5. Yes. That is the only way to reach such a conclusion: we don’t have DNA markers on the equine Y, equivalent to those that made possible the widely publicized Cohanim, Genghis Khan and Hemings studies in humans.

  6. One other conclusion reached by the science or by stud book researchers:
    As in nature,where only the toughest will survive,in horse racing after nearly 300 years and a tough selection made by racing results,it appears clearly that the blood of “Manachi”,as he was named,is the best in the world.he is truly “Malak el Kheil” The King of the Horses.
    I wish that Edouard could translate and post the article i send him on how the Darley was bought,not the British version but the Syrian one,just for the “petite histoire”

  7. We were looking forward to seeing Y-chromosome variations equivalent to mitochondrial DNA variations (or at least *some* variation!) but were disappointed when that nothing has so far turned up.

    However, I know everyone would be interested in the Syrian side of the Darley Arabian story! (No pressure, Edouard!)

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