Human cloning may be impossible and therapeutic stem cell cloning may be unnecessary - new research
As the debate on cloning of both humans and stem cells continues on both side of the Atlantic, latest research indicates that a cloned human may be impossible. An embryology conference in Washington DC, USA, heard that the particular nature of primate embryos could mean that attempts to clone them cannot be successful. Attempts to clone monkeys, primates with similar genetic makeup, have not been able to go beyond the early embryo stages, possibly due to the damage caused when the nucleus is removed from the egg. Although this technique was successful in the cloning of Dolly the Sheep by the Roslin institute in Edinburgh, Scotland, research has found that the cells in primate clones do not form distinct nuclei that contain all the chromosomes. The finding, by Advanced Cell Technology, adds further doubt to the potential for human clones, something which was already questioned following the high failure rate found in attempts already made with other animals, such as sheep. For scientists more concerned with stem cell development, therapeutic cloning of cells appeared less necessary following a find of a new type of 'perfect' cell. The need to find a cell which would not be rejected by the human immune system had initially led to attempts to clone human stem cells. Researchers at McGill university in Montreal, Canada, have found a cell found in bone marrow (mesenchymal stem cells) which is safe, even to the point of being transferred between species. Scientists have found no signs of rejection as the cells do not carry markers and have been successfully transferred from pigs to rats.