Daily chart: The sheep that changed the world

Main image:  TWENTY years ago Dolly the sheep, the first animal clone, was revealed to the world. She caused a sensation. Many scientists had believed cloning animals was impossible. Dolly’s creation showed that DNA in a differentiated cell could be repurposed through nuclear transfer, opening up two new possibilities. One, “reproductive cloning”, was the copying of individual animals. The other was the creation of embryonic stem cells (ES cells) capable of being turned into other types of cells. Various ailments are caused by a lack of specific types of differentiated cell. Making embryos through nuclear transfer seemed likely to provide ES cells with which to research and treat such conditions—something that came to be known as “therapeutic cloning”.Reproductive cloning has made steady progress. It has been used successfully in 20 species, including ferrets and camels. Meat and milk from cloned animals are routinely farmed and sold in the United States, Argentina and Brazil. Prized pet dogs and polo horses are now provided to customers—for a price. But therapeutic cloning, which required human embryos to develop nuclear-transfer techniques, raised ethical concerns. Press and public alike fretted about imminent human cloning and designer babies. It also turned out to be tricky. By 2006, nuclear ...
Source: Biotechnology - Category: Biotechnology Source Type: news