News that Chinese researchers have succeeded in growing healthy living mice from mouse skin cells takes scientists a significant step closer to human cloning, experts say, and is thus likely to reopen debate about the ethics of such reproductive techniques.
The new feat -- in which animals were grown from cells that had been reverted back to their embryonic state -- is technically different from cloning. But the outcome is the same in both cases: a genetically identical copy of the donor animal.
"We are fast forwarding to the era of designer babies," said Dr. Robert Lanza, chief scientific officer at Advanced Cell Technology Inc. in Worcester, Mass., who was not involved in the studies. "We have gone from science fiction to reality."
Cloning, in which the nucleus is removed from a cell and implanted in a fertilized egg, has never been achieved in humans. Nor has the new technique -- using what is known as induced pluripotent stem, or iPS, cells -- been tested in them. Because that process works in mice, however, it should also work in humans, Lanza said.
"We now have the technology to create iPS cells from skin or hair follicles. Combine that with showing that they can actually create a living organism, and that's pretty scary," Lanza said. "All the pieces are here for serious abuse. The only way to find out if it works in humans is if someone does it."
And that could happen in a backroom in Tijuana as easily as in a major laboratory, he said in reaction to Thursday's announcement. "You can order the necessary genetic constructs, the protocols are published and have been reproduced. There are a dozen approaches that could be used. What's very troubling is that if you have a piece of skin from anybody -- Albert Einstein, Marilyn Monroe, Michael Jackson -- you could create a child."
But "that is an experiment that shouldn't be done," said biologist Kathrin Plath of UCLA's Broad Center of Regenerative Medicine and Stem Cell Research, who was not involved in the research. "If you look back at the mouse cloning experiments," she noted, many died shortly after birth or suffered from genetic abnormalities.
The scientists involved in the new research agreed.
"It would not be ethical to attempt to use iPS cells in human reproduction," Fanyi Zeng of Shanghai Jiao Tong University said in a telephone news conference. "It is important for science to have ethical boundaries." Her study, she added, was "in no way meant as a first step in that direction."
