Gene-editing set to bring change in the equestrian world

Genetically modified polo horses stand in San Antonio de Areco, on the outskirts of Buenos Aires, Argentina January 30, 2025. REUTERS/Matias Baglietto

For many years, cloned ponies have excelled in the prestigious equestrian sport of polo, and the sport has now taken a further step into equine technology, with the birth of the first genetically edited horses.

Polo has diverged markedly from thoroughbred breeding for racing, in which only natural breeding is allowed. Other equine sports are in the middle, with artificial insemination (AI) and embryo transfer permitted in sport horse breeding.

Now, the genes of a star polo mare in Argentina, Polo Pureza, will live on in five genetically edited horses designed to outrun the polo legend herself. They are the world's first genetically edited horses, produced by scientists at Argentina's Kheiron biotech firm.

Scientists took genes from Polo Pureza as the genetic base for the five horses, editing the genes to increase explosive speed, while keeping the champion horse's other qualities. 

"There are certain muscle fibres that give it more explosiveness, a faster contraction, and the animal can have this greater explosive speed," said Gabriel Vichera, co-founder and scientific director of Kheiron.

"We do this by using the so-called genetic scissors techniques, which are molecular tools that allow us to go to any region of the genome, make a precise cut and be able to make a change in that genome."

Vichera said the horses comply with current Argentine regulations, and do not count as genetic doping, or genetically modified organisms. 

"We are not inventing anything artificial, but rather we are taking that natural sequence and introducing it into another natural horse, which is what nature does, but we do it faster and more targeted," Vichera said.

He said Kheiron is also working on modifying pigs so their organs can be compatible for transplants to humans, and on cows to give them more protein or shorter hair to withstand heat better.

Biotech scientists are unlikely to be hampered by government regulations in Argentina, where Javier Milei, elected president in 2023, dedicated his victory to Conan, his dog which had died, but not before five clones were produced from its cells. Now, Milei is frequently pictured with his cloned dogs, produced by Perpetuate Inc in the USA, which offers cloning as "a unique form of insurance" to pet owners.

Embryonic technology and cloning have allowed Argentina to become a leader in breeding, production and reproduction of horses.

It holds the world record for the number of commercially cloned horses, many of which are exported as animals, embryos, or semen. Kheiron Biotech has obtained up to 250 cloned animals per year, while Clonargen has generated up to 1,000 cloned embryos. 

The largest market is believed to be the United States, followed by the UK, Chile, Saudi Arabia, and the United Arab Emirates (where Argentine researchers offer scientific know-how to camel breeders).

For almost a century, Argentina has dominated World Polo Tour rankings, and embryo transfers since the mid-1980s and cloning have helped Argentine riders to continue their complete domination of the sport. The country is one of the largest exporters of polo horses, which can sell for more than €100,000 each.

The latest breakthrough for scientists at Kheiron required CRISPR-Cas9 technology to modify the MSTN gene, which regulates muscle growth, by transferring a small portion of a gene from one mare into another.

In such cases of gene editing, no foreign DNA is inserted. It differs from genetic modification, in which "foreign" DNA from another organism is injected.

There has been a shift away from genetically modified organisms (GMOs) towards gene editing, promoted by some as “the next big thing in agriculture.”

GMOs are banned in the EU, but proposals on new gene editing techniques have been discussed over the past 18 months. Now, the Polish presidency of the EU seeks to move forward with stalled proposals to remove a new generation of gene-edited plants from the stringent EU licensing and traceability requirements applied to GMOs.

The European Commission proposed in July 2023 that crops created using new genomic techniques be excluded from GMO regulations, but governments have been unable to agree.

As for gene-edited animals, that seems a step much too far for the EU. In the UK, the government seems to be moving to permit the growing of gene-edited crops in England and Wales, but the new legislation will not cover the use of this technology in animals.