GEORGE Cloney is some pig. He鈥檚 the first to be cloned by a technique that is apparently twice as efficient as previous methods and only one-tenth as costly.
The first step in cloning a mammal is to strip an egg cell of its own nucleus. This is usually done by the process known a enucleation, in which a needle is used to suck the nucleus out of the egg. The new technique, called 鈥渉andmade cloning鈥�, achieves the equivalent by simply chopping the egg in half.
Staining identifies the nucleus-free half of the egg, which is then fused with the cell to be cloned and stimulated to grow into an embryo. George became the first 鈥渉andmade鈥� cloned pig when born on 8 June. A further litter of 10 piglets has arrived since, all cloned from a single sow. This represents 21 per cent of the 47 cloned embryos that were originally implanted. Previously, the best cloning rate was around 7 per cent, says G谩bor Vajta of the Danish Institute of Agricultural Sciences in Tjele, who developed the process.
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Handmade embryos grow without the outer membrane called the zona pellucida, which becomes hardened during traditional cloning. This may make it easier for them to 鈥渉atch鈥� and grow, says Vajta.
