| The first mule cloned by scientists |
Science |
 The first member of the horse family to be cloned is a mule named Idaho Gem, the genetic brother of a champion racer. Researchers say two other mule clones are expected to be born this summer. The May 4 birth of Idaho Gem adds mules to the barnyard of cloned animals that already included sheep, cows, pigs, cats and rodents.
University of Idaho researchers cloned the mule using a cell from a mule foetus and an egg from a horse. Idaho Gem is the genetic brother of Taz, a champion racing mule, and the researchers said the cloned mule also will be trained to race. Cloning a mule is particularly unusual because such animals, hybrids from a donkey and a horse, are almost without exception sterile and unable to produce young. "A mule can't do it himself, so we thought we would give it a hand," said Gordon L. Woods of the University of Idaho, the leader of the mule cloning team.
Cloning horses next?
Now, said Woods, he plans to use the same techniques that worked on Idaho Gem to clone horses.
"We think the same sort of advances that we had to make to produce this cloned mule are important for cloning horses," said Woods. He is first author of a report appearing Friday in the journal Science.
Other researchers, however, said they expect the birth later this year of cloned horses produced by techniques slightly different from that used by the Idaho team.
Mules are bred by mating a male donkey with a female horse. The breeding success is about the same as among horses alone. Mating a male horse with a female donkey produces an animal called a hinnie. Both mules and hinnies can be either male or female, but they are almost invariably sterile.
Taz, Idaho Gem's brother, is a champion on the mule racing circuit in California and Nevada. Taz has gained fame in showdown races with another mule, Black Ruby, who has dominated the circuit.
To clone the racing mule's brother, researchers bred Taz's parents, a jack donkey and a horse mare, and allowed the resulting foetus to grow for 45 days. This provided the DNA needed for the clone.
The researchers then harvested eggs from horse mares. After removing the nucleus from each egg, the researchers inserted the DNA from the male fetal cells. The eggs were then placed into the wombs of female horses. Woods said to clone the mule, he and his researchers bathed the horse eggs in different concentrations of calcium. He said the calcium ratio that has been used for cloning other mammals produced only two pregnancies out of 132 attempts and no births. Higher calcium concentrations had better luck, leading to Idaho Gem and two other full-term pregnancies.
Courtesy: cnn.com
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