Great success of a new “artisan cloning” technique that uses a broken ovum
According to an article published on July 17, 2006 in New Scientist magazine (no. 2560, p. 18) a pig named George Cloney was the first to be cloned by a new technique, apparently twice as effective as previous methods with so much only one tenth of its cost.
The first step in cloning a mammal is to remove the nucleus of an egg. This is usually done through a process known as enucleation, in which a needle is used to remove the nucleus from the female reproductive cell. The new technique, called "handmade cloning", achieves the same result simply by splitting the egg in two.
Once broken, the half of the ovule that contains the released nucleus is identified and this is fused with the cell to be cloned, stimulating them to develop an embryo. George, who was born on June 8, has become the first pig cloned "by hand". Since then, a litter of 10 piglets has been born, all of them cloned from the same pig. This represents 21% of the 47 cloned embryos that were initially implanted. Until now, the best cloning rate was around 7%, says Gábor Vajta of the Danish Institute of Agricultural Sciences in Tjele, which has developed this process.
In this type of cloning, the embryos grow without the outer membrane, called the zona pelcida, which hardens during the traditional cloning process. According to Vajta, this makes it easier for the embryos to grow and "hatch."
Source: New Scientist