Scientists claim milestone in cloning with monkeys

The hope is that one day, such a procedure could be used to create transplant tissue that is genetically matched to an ailing patient. Because stem cells can form all types of tissue, the approach might one day help treat conditions like diabetes and spinal cord injury without fear of rejection by the patient’s body.

Scientists have tried for years to clone monkey embryos and extract stem cells because monkeys are more closely related to humans than other lab animals are. So monkey work has been expected to give hints about how to do this in people.

The success was reported earlier this year at a scientific meeting in Australia by Shoukhrat Mitalipov of the Oregon National Primate Research Center in Portland. It received limited media attention at the time, but the results were given new attention Tuesday by a London newspaper, The Independent.

A scientist from Michigan State University Jose Cibelli said that he had heard about Mitalipov’s presentation at the Australia meeting. “To me, it’s a breakthrough,” said Cibelli, who studies cloning and stem cells. The work shows “it is possible.”

In cloning to obtain stem cells, DNA from an adult animal is inserted into an unfertilised egg. The egg is grown into an early embryo, from which stem cells are extracted. These stem cells, and the tissue that develops from them, will be a genetic match to the source of the DNA.

The idea of doing this in people is controversial because the embryos have to be destroyed to obtain the stem cells.

Despite the monkey success, “we’re still far off to start dreaming about translating this technique to humans,” Cibelli said. That’s because the reported results were very inefficient, requiring many eggs to produce stem cells, he said.

Still, the work shows monkeys can be used to study the potential of embryonic stem cells produced through cloning, Cibelli said. “That’s a terrific tool.”