Op-Ed: The Way to Double Our Bet
June 4, 2004 5:50 pm
By Huntington F. Willard, PhD
Contact: Denise Haviland, 919-684-2850
This Op-Ed originally appeared in the June 4, 2004 issue of the News & Observer (Raleigh, NC). Download PDF.
The question is inevitable. Every time a Smarty Jones comes along, people want to know "Why not clone him?" After all, a winning stallion can be worth millions, so why not make an exact genetic duplicate? We heard this same question last year when Funny Cide came from behind to win the Kentucky Derby and went on to blow away the field in the Preakness. Alas, he could not close the deal. Empire Maker took the Belmont Stakes and turned Funny Cide into just another bridesmaid - the fifth time in seven years that the Derby and Preakness winner could not win the final leg of the Triple Crown.
But Funny Cide's third-place finish in the Belmont was not the only reason the cloning talk quickly subsided. Take a look at The American Stud Book. (No, it's not a compendium of pick-up lines from George Clooney and Viggo Mortensen. The Stud Book is the registry maintained by The Jockey Club for all thoroughbred horses in North America.) On page 5, under the heading "Breeding Practices Not Approved by The Jockey Club", it is clear that the Club has done for horses what President Bush's Council on Bioethics has tried to do for humans, which is to say, "Cloning is bad. Don't do it."
The Jockey Club has said it believes natural reproduction is better for thoroughbreds' short- and long-term welfare. And that may very well be true. The overwhelming majority of cloning experiments fail and even those animals that make it to term often develop problems later in life. The most famous cloned mammal, Dolly the sheep, was put to sleep at the tender age of six after it was found she was suffering from a progressive lung disease, which some believe was related to her being a clone.
The Club's view may also have something to do with notions of fair play: if cloning were the answer, then why not just get a lock of Secretariat's hair, send it off to Clones-R-Us and be done with it? Apparently, some mule enthusiasts are thinking just that. Last year, a university research program sponsored by the president of the American Mule Racing Association (yes, apparently there is such an organization) produced a cloned mule named Idaho Gem. Mules are crosses between male donkeys and female horses, and are sterile; thus, assuming the technical barriers could be overcome, cloning would be the only route to replicating mule versions of Man o'War.
But while cloning duplicates an organism's genome, it is far from being the biological equivalent of a crystal ball. A clone and the organism it was cloned from may have their genes switched off and on during development in patterns much different from each other. The broader environment - diet, lifestyle, horseflies - is also difficult to duplicate. Look at the ways in which identical twins-naturally occurring clones - so often choose different paths and exhibit different health histories. Better yet, go rent The Boys from Brazil. The point is, whether it's Mr. Ed or Hitler, genes are only part of the story, albeit an important part.
Of course, cloning is just one use of genome technology. It may be uppermost in the public's mind thanks to Hollywood 's infatuation with it. But if one continues to leaf through The American Stud Book, it becomes clear that, despite its cloning ban, even the staid Jockey Club sees the merits of the new field of genome science as a whole. In fact, the book makes very explicit demands regarding genetic typing. Since 2001, all stallions and broodmares must be DNA typed in order to verify their parentage. No surprise there: if I were paying a $500,000 stud fee, I imagine that "Who's your Daddy?" would be the first question I'd want answered.
Beyond simple DNA typing, I hope and expect that horse-centric veterinary research programs in places like Texas and Kentucky will kick and buck until the entire equine genome has been sequenced. After all, the genomes of some 150 other organisms have been sequenced, including, of course, Homo sapiens. So why not the horse? Already some thousand horse genes have been mapped to chromosomal locations, while several causative genes for equine diseases have been identified. Still, we've barely scratched the surface. Given the trifecta of 1) the horse's unique evolutionary history, 2) the fact that the equine industry contributes more than $25 billion to the US GDP, and 3) the potential utility of the horse genome in understanding mammalian fertility, disease resistance, and athletic performance, decoding the horse's genome strikes me as a sure bet.
So never mind cloning, which is a long shot anyway - put your money on the genome. Smarty Jones and his ilk are offering something with much better odds and a higher payoff.
Huntington F. Willard is Director of the Institute for Genome Sciences & Policy at Duke University.