Dolly the Sheep In 1997, Scottish researcher Ian Wilmut and his colleagues captured newspaper headlines with the announcement that they had cloned an adult sheep by transplanting the nucleus from an udder (mammary) cell into an unfertilised egg cell from another sheep.  They achieved the necessary dedifferentiation of the nucleus by culturing mammary cells in nutrient-poor medium, forcing the cells into the G0 "resting" phase of the cell cycle. They then fused these cells with sheep egg cells whose nuclei had been removed. The resulting diploid cells divided to form early embryos, which they implanted into surrogate mother. One of several hundred of these embryos successfully completed normal development. DNA analyses have shown that the chromosomal DNA of this sheep, "Dolly," is indeed identical to that of the nucleus donor. Relating Topics - Mitosis - A Explicative Cell Division

Dolly is the the first cloned animal on Earth.

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