Several theories have been suggested as to why the vast majority of cloning attempts end in failure, however results of a recent study have laid at least some of the blame on just one solitary gene. Dr K John McLaughlin and his colleagues discovered that only a small percentage of cloned mouse embryos correctly express a gene called Oct4 that is vital for normal development. The researchers found that just 34% of cloned embryos were expressing Oct4 in the right places during the first crucial days of early development, however many of these were expressing the gene at abnormal levels. Further tests showed that the small number of cloned embryos that went on to develop to a stage where they produced stem cells all expressed Oct4 in the right places and in the right amounts. “Basically, it’s a miracle that cloning actually works. If you don’t have Oct4 in the right place at the right time, at the right levels, you won’t get an embryo,” McLaughlin said.
SOURCE/REFERENCE: Reported by www.reutershealth.com on the 14th May 2002