Birth of cloned foal using oocytes is first for veterinary medicine

Gainesville, Fla.

-- A cloned foal -- the first created using oocytes from a live mare -- was born at the University of Florida College of Veterinary Medicine (UF) in March. So far, the foal is in good condition.

The foal, named Mouse, was created through a joint effort between UF and Texas A&M University College of Veterinary Medicine and Biomedical Sciences (TAMU). The process started about two years ago, when Kit Knotts, Mouse’s owner, began searching for a new horse. She wasn't looking for any horse, but one with the same characteristics as her prized Lipizzan stallion Marc. Her local veterinarian mentioned TAMU was cloning horses. Knotts ran with the information.

TAMU pioneered foal cloning technology in 2004 and has since produced 14 cloned foals, 12 of which lived and thrived.

The difference in this case was the process, the school reports, which began with a biopsy of skin cells from Marc, the Lipizzan stallion, and oocytes collected from live research mares at TAMU. A new cloning technique used in mice that showed decreased birthing problems also was used, TAMU says. Viable embryos were developed at TAMU and sent to the Hartman Equine Reproduction Center for embryo transfer in North Texas, where they were implanted in Minnie. Minnie, the mare who carried Mouse, stayed at the facility for 200 days before being transferred to a new home in Florida.

It was in Florida where, at just less than 300 days gestation, Mouse arrived with the help of veterinarians at UF’s Large Animal Hospital. The delivery was overseen by Margo MacPherson, DVM, an equine reproduction specialist and associate professor at UF, and Katrin Hinricks, DVM, PhD, TAMU’s “cloning guru.” Malgorzata Pozor, DVM, PhD, a reproduction specialist and clinical assistant professor at UF; Rob MacKay, BVSc, PhD, a large-animal medicine specialist and UF professor; and Stephanie Meyer, DVM, a third-year large-animal medicine resident also assisted in Minnie’s arrival.

The team at UF was prepared to handle common problems associated with the births of cloned foals. The delivery went off without a hitch, says UF, and a few problems diagnosed days after Minnie’s birth -- like the removal of umbilical cord remnants and fixing a urinary problem -- have been rectified through surgery.

Knotts reported that Mouse is doing well with 30-year-old Marc, her genetic clone. And that's not all. Another mare is pregnant with Marc's second clone. The surrogate mare is set to head to UF in mid-August prior to the birth, UF says.