Human cloning a step closer

Researchers have created cloned human embryonic stem cells from adult cells for the first time, according to a report in the journal Cell Stem Cell. Last year researchers in the US managed to make cloned embryonic cells using cells from fetuses, but now a team from Korea and the US have achieved this with adult cells.

The researchers managed to inject DNA from adult cells from a 35 or a 75-year old man into donated human eggs, then kick-started them into dividing to create embryonic stem cells - very early cells that can create all the tissues in the body. however, the success rate was very low, with just two viable cloned cells out of 77 attempts.

While the technology is still a long way away from being usable to clone living humans - if that is agreed to be ethically right - the technique could help with generating genetically identical donor organs for transplants. But it still remains to be seen if it's more or less efficient than the recently-discovered alternative for generating stem cells from adult cells - a technique called induced pluripotent stem cells.