Milestones in Cloning

1928
Hans Spemann uses a salamander embryo to demonstrate that the cell nucleus directs cellular division. Ten years later, he proposes replacing the nucleus in an egg cell with the nucleus from another cell.

1952
Robert Briggs and Thomas J. King extract the nucleus from the cell of an advanced frog embryo and insert it into a frog egg, that then undergoes division.

1963
J. B. S. Haldane coins the term clone.

1972
John Gurdon transplants the nuclei from frog embryo cells into unfertilized eggs, that develop into short-lived tadpoles. He later shows that transplanted nuclei revert to an embryonic state.

1978
Louise Brown, the first baby conceived via in-vitro fertilization, is born. 1984 Steen Willadsen produces a live lamb from early sheep embryo cells in a process known as twinning. It is later used on other animals.

1995
Ian Wilmut and Keith Campbell create the world’s first cloned sheep, Megan and Moran, from embryo cells. A year later, they clone the first sheep from adult cells, Dolly. At the age of 6, Dolly is euthanized when veterinarians discover she has progressive lung disease. Research suggests that she may have been susceptible to premature aging.

1998
James Thomson and John Gearhart announce that they have established the first cultures of human embryonic stem cells, derived from fertilized human eggs before they could grow into specialized cells. 2001 Scientists at Advanced Cell Technology clone a gaur, an endangered oxlike species. The animal appears healthy when it is delivered by its surrogate mother, a cow, but dies two days later from a bacterial infection.

2002
The first cloned pet, a cat named cc, short for copy cat, is produced by scientists at Texas A&M.

2003
Scientists finish mapping the human genome, two years ahead of schedule.

2003
By replacing DNA in egg cells with DNA from human body cells, Advanced Cell Technology says, it has developed a human embryo that progressed to 16 cells. 2004 South Korean scientists say they have cloned a human embryo and extracted stem cells from it.

link: http://www.nytimes.com/2004/02/12/science/13MILE.html?ex=1216526400&en=6af7c51105421a6d&ei=5070