THE FIRST EVER CLONE DOLLY: How the feat was achieved by scientists

The first ever mammalian clone of the world has been created by Ian Wilmut and his team of researchers at Roslin Institute, Edinburgh, Scotland. Born in February 1996, the name Dolly has been given after an American country singer, Dolly Parton.

The clone was created from a fully differentiated non reproductive cell of an adult sheep. The researchers took udder ( a fully differentiated tissue) from six year old sheep, Fin Dorset Ewe and placed it in special solution that controlled cell cycle of cell division. The cell was deprived of certain nutrients. The unfertilized egg was obtained from another adult sheep at the same time.

Its nucleus was carefully removed leaving the intact cytoplasm in egg. The nucleus of the udder cell was taken out and transferred into a nucleus-free egg. This was facilitated by applying mild electric shock. The newly transplanted nucleus soon became functional according to the cytoplasm in which it had been artificially transferred. This viable combination underwent cleavage like normal zygote.

This so called embryo was transplanted into the uterus of the third sheep that acted like a surrogate mother. Finally, a normal healthy little lamb, Dolly was born in February, 1996. It was genetically similar to the clone mother, from which the nuclear DNA was taken out.

Thus, Dolly has only a single parent because she has been born asexually. Still, it is true that the success rate has been very low till date. Out of the 277 singly transferred eggs, only 29 really grew into embryos. The studies on such clones may pave the way for embryologists to try their hands in another spheres of embryology as well. The genetic blueprint may be altered in the embryonic stage so that many hereditary diseases, that are transmitted genetically, may be treated at the embryonic stage themselves.