Cloning from chromosomes

Somatic cell nuclear transfer (SCNT), also known as "therapeutic cloning", is an intensive area of study for stem cell scientists. It potentially provides a way to make patient-tailored embryonic stem (ES) cell lines to avoid the problem of immune rejection of cells transplanted for therapy

It has long been believed in the cloning field that successful SCNT requires the use of unfertilised eggs. Eggan and colleagues at Harvard University now publish a remarkable technique that proves that unfertilised eggs are not required, at least not in mice1. They show that very early embryos can be used as recipient cytoplasts for nuclear transplantation, allowing the production of cloned animals and somatic cell–derived ES cell lines similar to those needed for patient-tailored ES cell therapies.

The procurement of human oocytes is a thorny issue because of the invasiveness of the procedure to retrieve them from women's ovaries. The authors argue that it will be easier to obtain early human embryos from in vitro fertilization (IVF) clinics than unfertilised oocytes, thus overcoming one of the major logistic and ethical hurdles of SCNT. Early embryos are destroyed in the process, but they would be ones donated by couples who had excess embryos following IVF.

http://www.nature.com/stemcells/2007/0706/070607/full/stemcells.2007.30.html