When we hear the word "clone," most of us think of "Dolly" the sheep. She was the first mammal cloned from an adult cell. Dolly was born in 1996 and was put to sleep in 2003 due to a lung tumor. Although they may not be as well known, other creatures have been created by cloning after Dolly. For example, in 2007, scientists in South Korea cloned Turkish Angora cats. The scientists not only succeeded in cloning the cats but also successfully modified their genes to produce red fluorescent protein. So when ultraviolet light was held over them, the cats glowed red.
One may wonder the benefit of making animals glow. Scientists sometimes modify cells with a gene that produce fluorescent proteins as a marker of genetic change in cloned animals. It was also previously done for cloned pigs, for example. In the case of the cloned cats, South Korean scientists used skin cells of a Turkish Angora cat and encoded for a coral fluorescent protein before cloning. Proponents believe that cloned animals can be beneficial in the study and cure of genetic diseases while others oppose cloning on ethical grounds.
More about cloning:
- The beginning of cloning studies is believed to be the demonstration by Hans Adolf Edward Dreisch in 1885 that separation of the cells of a two-celled sea urchin results in two individual sea urchins.
- In 1975, J. Derek Bromhall produced an advanced rabbit embryo by transferring the nucleus of a rabbit embryo cell to a rabbit egg cell.
- In 2013, Shoukhrat Mitalipov and his colleagues produced human embryonic stem cells through the fusion of a skin cell and an egg cell.