Scientists in Oregon claim to have successfully produced rhesus macaque embryos using somatic cell nuclear transfer with egg and skin cells taken from adult monkeys. The Scientist first reported on this back in June when the head of the research team, Shoukhrat Mitalipov, presented the results at a stem cell meeting in Australia.

The paper is published online today (November 14) on Nature's website and is accompanied by a study showing verification of the results by an independent lab.

Mitalipov and his collaborators managed to produce two embryonic stem cell lines from more than 300 oocytes they harvested from several monkeys. This represents only a 0.7 percent derivation efficiency, but this is the first time that scientists have produced embryonic stem cells using SCNT in animals other than mice, and the only instance of embryo cloning in primates.

While these results advance the hope of creating patient-specific stem cell lines in humans, in the post-Woo-Suk Hwang era, Nature seems to be proceeding cautiously. The journal's press office sent out an email with news of the study's publication and a statement that reads, in part, "Due to continuing speculation about this work we are publishing today and lifting the embargo with immediate effect."

British newspaper The Independent reported on the study earlier this week.