SOUTH Korean scientists announced on Wednesday that they have produced the worldâ€™s first cloned dog, named Snuppy. Here is a chronology of cloning since 1997:
February 24, 1997, Scientists at Scotlandâ€™s Roslin Institute reveal they have cloned a sheep named Dolly using DNA from a single adult sheep cell.
July 24, 1997, PPL Therapeutics say they have created Polly the lamb and four others from the same single cell line. All carry human genes.
April 13, 1998, Dolly the sheep becomes a mother, giving birth to her first lamb, a female called Bonnie.
July 22, 1998, Researchers at the University of Hawaii say they have cloned three generations of mice from adult cells.
February 2002, Japanese researchers who cloned a dozen mice report that virtually all the animals died early.
Scientists at Texas A&M University say they cloned a cat called CC, for carbon copy.
February 27, 2002, A House of Lords committee gives Britainâ€™s scientists a green light to pioneer the cloning of human embryos for research and set up the worldâ€™s first embryo cell bank.
February 14, 2003, Six-year-old Dolly the sheep, the worldâ€™s first cloned mammal, is given a lethal injection after signs of progressive lung disease are discovered.
August 6, 2003, Italian scientists say they have created the worldâ€™s first cloned horse, Prometea, from an adult cell taken from the horse who gave birth to her.
December 16, 2003, Scientists at Advanced Cell Technology of Worcester, Massachusetts, say they have successfully repeated the cloning of a human embryo, growing it to the 16-cell stage.
February 11, 2004, South Korean and US researchers say they have cloned a human embryo and extracted embryonic stem cells from it. The experiment is the first published report of cloned human stem cells.
August 22, 2004, Pope John Paul condemns human cloning as an arrogant attempt to improve on Godâ€™s creation.
May 19, 2005, South Korean scientists, who cloned the first human embryo to use for research say they have used the same technology to create batches of embryonic stem cells from nine patients.
July 11, 2005, Spain plans to introduce legislation allowing therapeutic cloning, a decision likely to bring a new clash between the socialist government and the Roman Catholic church.
Therapeutic cloning involves creating embryos as a source of stem cells to cure diseases.
The process is controversial because the embryos are later discarded.
Chronology: Key developments in cloning