BUENOS AIRES — Moments before the world’s top polo players prepared to compete in the world’s most important polo tournament, the stars from two rival teams lined up on the field on horseback, mallets in hand, to pay homage to a champion.
Her name was Dolfina Cuartetera.
She was a legend in Argentina’s polo Hall of Fame and winner of the most prestigious awards for horses in the sport. She was as fast as she was agile, as explosive as she was docile, a mare with the stamina and strength to outrun and outlast any other. As her owner, the world-renowned polo player Adolfo Cambiaso, put it: “She was genius; she was Messi, Maradona.”
Cuartetera wasn’t at the Argentine polo championship this year. She died in May, at the age of 22. But the four representatives of the defending champion La Dolfina team — including Cambiaso and his son — sat atop horses that looked just like her, with the same rich bay coloring and a splash of white on the nose. The horses from the opposing team resembled her, too.
“Cuartetera was the mare that marked Adolfito’s career, the one that made us tremble and thrill in so many finals, the one whose runs and plays remain in everyone’s memory,” the announcer said, “until he decided to multiply her.”
“Her clones, and the children of her clones, are present at this moment on the field, on both teams.”
This futuristic experiment had its origins in 2006, when Cambiaso’s beloved stallion Aiken Cura limped off the field, and it became clear that the horse was in his final days. The star player had an idea: He asked a veterinarian to save some of Aiken Cura’s skin cells.
A decade had passed since the birth of Dolly the sheep, the world’s first cloned mammal. Scientists in Italy had cloned the first horse in 2003. And the commercial horse-cloning industry had arrived in the United States.
Cambiaso decided to take a gamble. He had a Texas laboratory clone Aiken Cura, and then Cuartetera.
What began as an effort to immortalize those champions has now become a massive, multimillion-dollar industry. Argentina’s new president, Javier Milei, who has four clones of his late dog, recently tapped a prominent cloning expert to head the country’s top public science agency.
The possibilities of this experiment — and its long-term risks — are yet to be fully understood.
But the extent to which this polo-obsessed nation has already fundamentally transformed the sport and the nature of horse breeding was evident on the field at the Argentine Open in Palermo in late November. As the players and the clones watched a video montage memorializing the late original champion mare, her name flashed across the screen.
“Dolfina Cuartetera,” it read. “3 February 2001 — ∞.”
Inside a horse-cloning lab
When Gabriel Vichera was 30, working in an Argentine lab that had just cloned the first horse in Latin America, he read one day that Cambiaso had auctioned a Cuartetera clone for $800,000. The young scientist saw a business opportunity and pitched it to investors: a company dedicated to cloning horses for Argentine polo.
More than a decade later, Vichera said his firm, Kheiron Biotech, clones about 100 horses each year — more than just about any company in the world — including about 10 Cuarteteras. Next year, the company expects to double its output. Although clones are still not permitted in horse racing, top-flight horses sell for upward of $1 million to the best polo clubs in Argentina, to endurance riders in the Middle East and to show-jumping equestrians around the world.
On a recent day in a dimly lit lab, as electronic music blasted from speakers, Vichera peered into a microscope and spun various nobs to control two sets of miniature tweezers. His rolled sleeves exposed tattooed arms: a DNA chain and the words “updating nature,” next to the molecular formulas of horses he cloned.
Now he was about to make another one.
“Do you see something round on the left?” he asked. “That’s the egg.”
Making minuscule movements, he delicately placed DNA material from an existing horse just outside of the egg. Then a colleague used an electric shock to push the material in, setting in motion a new life for an old horse.
When Vichera first started cloning horses, about half of those born would suffer a deformity or die. But when he started using stem cells for his cloning procedure, defects and losses became rare.
In many ways, it makes sense that this South American nation would become a leader in horse cloning. In addition to its world-famous polo scene, it has permissive regulations, a sophisticated biotechnology sector and extensive farmland. It is also one of the world’s top exporters of horsemeat. To make a clone embryo, scientists need eggs extracted from horse ovaries, and they found plenty in Argentina’s slaughterhouses.
Early on, horse cloning was met with skepticism from many in the polo industry and outright horror from others who saw it as a work of science fiction.
Ethicists still argue that cloned horses create an uneven playing field in a sport that hinges heavily on a horse’s performance. Competing with cloned horses removes a great deal of room for error, said Francisco Javier López Frías, a sports ethicist at Pennsylvania State University. At what point, he said, does a polo player’s accomplishment become “sort of the laboratory’s accomplishment?”
But over the past decade, the entire polo industry has had to get on board. Even one of the main detractors of cloning in Argentine polo — the Ellerstina club — has its own clones. “They were falling behind,” Vichera said. “They saw that it worked.”
A visit to a horse-clone farm
The eggs from Vichera’s lab are eventually delivered to a farm about an hour away, where they are implanted into surrogate mares.
The drive there cuts through Pilar, a Buenos Aires suburb that boasts more than 100 polo grounds. A turn down an unmarked, rural dirt road leads to the Kheiron farm, home to hundreds of pregnant or soon-to-be pregnant horses.
One of those horses, “Receptor 1569,” was in her 14th day of gestation, meaning it was time for an ultrasound. There was Cuartetera, the newest clone of the polo legend, moving around in the mare’s uterus. An embryo with champion potential.
At another farm just a few minutes away, cloned foals and fillies stuck close to mothers that looked nothing like them.
“It’s the nursery,” Vichera said as he walked into a paddock. There was a Cuartetera about 2 months old, another just 3 weeks old. A snapshot of different moments in a horse’s life span, at one farm, all at once.
They are not all the same horse. Each of the Cuarteteras have their small distinctions, a result of nature (genes that express themselves more than others) and nurture (experience in utero or in the early years of life). They have subtle differences in temperament. The white marks on their noses are all slightly different, too.
But given the right care and training, the clones would almost certainly share traits that made the original such a legend.
It used to take breeders hundreds of births to produce a competitive polo horse. Mares are only fertile in the spring, which coincides with the most important polo tournaments of the year, making it difficult for champions to both compete and breed. Instead, when you clone a horse, and then breed from those clones, Vichera said, you are “starting with genetics that you know are elite.”
“So you don’t have to have 100 births to find a good animal. You might only need 10,” Vichera said. “You’re not just cloning your horse. You’re cloning your moneymaking factory.”
Using embryo transfers, a single horse can now give birth to as many as 10 foals per year, instead of one, said Andres Gambini, a veterinarian and researcher at the University of Queensland in Australia, who was also part of the team of Argentine scientists who cloned the first horse in South America.
The sheer volume of today’s cloning operations raises the question: How many clones are too many?
“One of the things that you need for genetic progress is genetic variability,” Gambini said. “When you are using cloning and you are staying with the same genetics over and over and over, then the genetic variability starts to decrease.”
Long term, if left uncontrolled, this could lead to inbreeding and even fertility problems in horses, Gambini said.
Argentina imposes few rules on cloning, and polo association leaders place no restrictions on how many cloned horses can play in a game, leaving it up to the companies and the teams to define their own limits.
Vichera and his team have begun combining cloning with gene editing.In mid-December, they successfully implanted seven cloned, genetically modified embryos. If the pregnancies are successful, the world’s first genetically designed horse will be born next year — a horse whose genes have been edited to be stronger and faster, a sort of polo superhorse.
If he gets the green light from Argentine regulatory authorities, the scientist hopes to take this technology to the next level — changing the sex of a clone, for breeding purposes or perhaps to make an even better pony. If he were to clone an elite stallion, Vichera wonders, could that same horse be even more powerful as a mare?
Fielding a team of clones
La Dolfina was trailing behind by a point in the third period of the final match of the Argentine Open, the Dec. 3 match that would determine if the powerhouse team would defend the sport’s most important championship title.
As the crowd in the packed stands went silent, Cambiaso’s 18-year-old son, Adolfo “Poroto” Cambiaso — on the back of Cuartetera clone B09 — sent the ball flying up the field. His teammate, David Stirling, knocked it to a perfect opening.
The elder Cambiaso seemed to come out of nowhere, on the lightning-fast Cuartetera clone B06, the mare he has often described as the most similar to the original. Together, they made a run for it, racing past all the other horses. The star player struck the ball into the goal to tie up the game.
“Golazo, that’s how you play polo,” said an announcer.
After a razor-tight final, La Natividad clinched the championship. La Dolfina relinquished its title. But Cambiaso’s experiment saw yet another success.
A Cuartetera clone matched the feat of the original. For a third year, the prize for the best horse of the most important tournament in polo went to Cuartetera B06.