Dolly

1 Pages 195 Words

How Dolly Was Made

In February of 1997, Dolly, was the first mammal to be cloned from an adult sheep. The world was astonished by this feat, because he drew attention to the theoretical possibility of cloning humans. The clones were made from "cultured cells derived from easily obtained tissue should bring numerous practical benefits in animal husbandry and medical science." "Cloning is based on nuclear transfer, the same technique scientists have used for some years to copy animals from embryonic cells. Nuclear transfer involves the use of two cells. The recipient cell is normally an unfertilized egg taken from an animal soon after ovulation…The donor cell is the one to be copied. A researcher …holds the recipient egg cell by suction on the end of a fine pipette and uses an extremely fine micropipette to suck out the chromosomes, sausage-shaped bodies that incorporate the cell's DNA. (At this stage, chromosomes are not enclosed in a distinct nucleus.) Then, typically, the donor cell, complete with its nucleus, is fused with the recipient egg. Some fused cells start to develop like a normal embryo and produce offspring if implanted into the uterus of a surrogate mother."...