October 17, 2003

Cloned Mules Healthy, Providing
Insight into Nature vs. Nurture Debate

MOSCOW, Idaho – In the five months since Idaho Gem caught the world’s attention as the first equine clone, the little mule has proven himself healthy, vigorous and just a bit of a ham.

Dirk Vanderwall, University of Idaho assistant professor of animal and veterinary science, said Idaho Gem and his two younger brother clones appear to be normal and healthy foals.

Vanderwall, Gordon Woods, UI professor of animal and veterinary science, and Ken White, a Utah State University professor of animal science, formed the scientific team that won the international horse race to clone the first equine. The initial success with Idaho Gem’s birth May 4 was rapidly followed by the birth of Utah Pioneer on June 9 and Idaho Star on July 27.

All three foals have hit the road since to appear individually at fairs in Idaho and California and Utah State University’s homecoming celebration.

“Probably the most frequent question we get is about the foals’ health,” Vanderwall said. “People ask whether we see any health issues that could be related to the cloning process.”

The appearances resulted in contacts with more than 25,000 fairgoers and helped the lion’s share of visitors conclude the same thing: “All three are typical, normal, healthy foals,” Vanderwall said.

The foals are monitored at least five days a week by at least visual inspections by veterinarians, most often Vanderwall and Woods. The foals also are monitored with standard physical exams every three weeks and every three months will be subject to full blood chemistry tests.

“What can we learn? What can we study about the clones? What becomes evident over the life of the clones?” Vanderwall said those will be the basic questions guiding future research.

There are differences already evident in the mules because the three foals that are genetically identical triplets had different surrogate mothers. Idaho Gem, the first, was the heaviest at birth, weighing 107 pounds. Utah Pioneer, the second, was the lightest, weighing 78 pounds or 29 pounds less. Idaho Star, the third born, weighed 87 pounds.

All three mares are similar in size, and all are in good health. Vanderwall said the different birth weights may reflect whether the mare had carried a foal before the clones. Detailed reproductive histories of the mares are not available.

Both the mothers’ role and each clones’ response to its environment as the mules grow will provide insight into the debate about whether nature or nurture rules an animal’s future.

“It really does zero in on what is genetically controlled and what other factors come into play,” Vanderwall said.

The three clones, all cloned from the same fetal mule skin cell line, can only be compared to each other. They were not cloned from an adult so there is no mature animal with which to compare them.

The same male donkey, a Spanish jack named Coalee McGee, and quarter horse mare, Mesmerizer, have been paired to produce several foals, including the fetal tissue from which the clones were developed.

Two of the clones’ brothers, Taz and Chinook Pass, raced this summer at the

California State Fair in Sacramento where Idaho Gem was on display in late summer. Both are dark brown mules marked similarly to the clones.
The clones’ future probably will include race training as 2-year-olds. “They’re bred to be athletes, so one test of their fitness will be their athleticism,” Woods said.

Another frequent question fielded by the scientists has been whether the clones’ personalities are different. Vanderwall said he believes Idaho Gem and the youngest clone are the most similar, adding, “They’re the most personable, and they like to approach people.”

From that aspect, there does not seem to be a direct link to the mares’ personalities. Idaho Dawn, the surrogate mother of the youngest clone, is the most wary of the three horses.

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Contacts: Dirk Vanderwall, UI assistant professor of animal and veterinary science, (208) 885-7414, dirkv@uidaho.edu, or Bill Loftus, College of Agricultural and Life Science Communications, (208) 885-7694, bloftus@uidaho.edu