Note: This article originally appeared in the July 2005 issue of EQUUS magazine.
Two elite equine competitors–one an endurance horse and the other a show jumper–have been cloned. A colt cloned from Pieraz, a two-time endurance world champion owned and ridden by Valerie Kanavy, was born February 25, 2005 in Italy. A colt cloned from an anonymous champion European show jumper was born about a month later at Texas A&M University’s College of Veterinary Medicine and Biomedical Sciences. They are the second and third horses to be cloned. The first, the Haflinger Prometea, was born in May 2003.
Kanavy decided to clone her horse, popularly known as Cash, after learning that researchers at the French lab Cryozootech were looking for accomplished, athletic horses to participate in cloning research. The company is dedicated to preserving the genes of exceptional horses for use in producing cloned offspring. “I’ve always said it’s a pity that he wasn’t a stallion,” she explains.
In 2002 scientists cultured cells from the Arabian gelding and stored them in liquid nitrogen. The Italian lab LTR-CIZ, which produced Prometea, performed the cloning procedure and the embryo transfer that led to the foal’s birth. The scientists employed the same technique–cell nuclear transfer–used in cloning Dolly the sheep in Britain in 1998.
The colt was the only live birth from 34 embryos implanted in 12 mares, according to Eric Palmer, founder and chairman of Cryozootech. The foal weighed 93 pounds at birth and was described as being in excellent health by scientists at the LTR-CIZ facility. Cryozootech owns the foal, but Kanavy has the rights to his semen for breeding purposes and will receive a percentage of the revenue should the colt be sold.
An Achievement at A&MCryozootech, which maintains a genetic bank with samples from 30 elite equine athletes, supplied the cells for the foal born at Texas A&M. That procedure was privately funded, and the bay colt known as Paris Texas is privately owned.
The donor cells for Paris Texas came from an aged stallion. They were cultured from a skin biopsy and then frozen at Cryozootech in France. Upon arrival at Texas A&M’s equine embryo laboratory, headed by Katrin Hinrichs, DVM, the cells were thawed and put into a culture medium to grow. Horse oocytes (eggs) were matured in an incubator and then used for the nuclear transfer procedure. Six embryos were produced; ultimately they yielded a single foal. The pregnancy and birth were without complication, although the foal was more than a month overdue. “The great thing is that Paris Texas is healthy,” said Hinrichs in a statement. “This is certainly the goal of our work.”
The foal’s owner plans to breed but not compete him. “Cloning is not a way to produce competitors,” Hinrichs said. “There is just too much variability in the environment that a cloned foal experiences, both in the uterus and after birth. Just the fact that he spent his first seven days in an incubator can affect Paris Texas’s growth rate after birth and even his performance as an adult. However, as a sire, Paris Texas should produce the same quality of foals, with exactly the same genetics, as did the donor stallion.”