Embryo Project Encyclopedia Articles

In 1995 and 1996, researchers at the Roslin Institute in Edinburgh, Scotland, cloned mammals for the first time. Keith Campbell, Jim McWhir, William Ritchie, and Ian Wilmut cloned two sheep, Megan and Morag, using sheep embryo cells. The experiments indicated how to reprogram nuclei from differentiated cells to produce live offspring, and that a single population of differentiated cells could produce multiple offspring. They reported their results in the article 'Sheep Cloned by Nuclear Transfer from a Cultured Cell Line' in March 1996. This experiment led the Roslin team to later clone mammals from adult body cells and to genetically engineer mammals.

Advanced Cell Technology (ACT), a stem cell biotechnology company in Worcester, Massachusetts, showed the potential for cloning to contribute to conservation efforts. In 2000 ACT researchers in the United States cloned a gaur (Bos gaurus), an Asian ox with a then declining wild population. The researchers used cryopreserved gaur skin cells combined with an embryo of a domestic cow (Bos taurus). A domestic cow also served as the surrogate for the developing gaur clone. The successful procedure opened the opportunity to clone individuals from species for which there are few or zero live specimens. The official release of this experiment's data was published in the paper 'Cloning of an Endangered Species (Bos gaurus) Using Interspecies Nuclear Transfer,' in October 2000. In the article, the researchers presented data collected from several cloned fetuses that were aborted before the full term of 283 days. At the time of publication, the gaur bull fetus, named Noah at birth, had developed for greater than 180 days. Noah was born on 8 January 2001, but died two days later due to dysentery. The development, birth, and death of Noah became a platform for conservationists and ethicists to critique the role of cloning in society and as a method to conserve species.