PPL Therapeutics Ltd
The generation of mammals using somatic nuclear transfer (SNT) remains an extremely inefficient technique. Loss and/or instability of parental imprinting have been cited as major contributory factors. It has also been suggested that imprinting problems could impact on the utility of embryonic stem (ES) cell based cell therapy. I will argue that whilst there is no doubt that imprinting errors occur and have the potential to disrupt developmental events, they are not the principal culprits in SNT and are probably irrelevant to future ES-based stem cell therapy.