The birth of the world’s first cloned horse has been announced. The healthy female foal – named Prometea – was born to her genetically identical surrogate mother on 28 May. The breakthrough follows the cloning of a mule earlier in 2003.
Cesare Galli, director of the Laboratory of Reproductive Technology in Cremona, and colleagues created Prometea by fusing the nucleus of a skin cell taken from the mother with an empty egg from another horse. The resulting embryo was returned to the mother’s womb after being cultured in the lab.
Galli says cloning horses could help boost good breeds and might even help replicate equine champions. But he warns: “Although they will have the same genetic background, other factors such as training, the coach, their environment might have an effect.”
Although the current regulations governing thoroughbred horses ban clones from competing, some industry experts believe this may not last (New Scientist print edition, 7 June 2003).
The researchers fused the nuclei of skin cells taken from one male Arabian thoroughbred horse and a one Haflinger mare with eggs taken from slaughtered abattoir horses and emptied of their own DNA.
But success was far from guaranteed. Of the 841 successfully reconstructed male and female embryos, just eight male and 14 female embryos developed to the earliest “blastocyst” stage after seven days of culture.
And of the 17 embryos inserted into the mares, only four lead to pregnancies. Prometea, born after 336 days, was the only one to survive.