PITTSBURGH, PA, October 31, 2001 ( – It is reported that American scientists have successfully created rhesus monkey embryos by cloning adult monkeys. The successful cloning attempts have raised renewed fears of human reproductive cloning since it was believed that cloning primates would be far more difficult than other species such as sheep and goats.

Professor Don Wolf, of the Oregon Regional Primate Research Center, said: “We have been working with somatic cells and believe that success is just around the corner as the cloned embryos created from them are growing well in vitro.” Wolf is expected to attempt implantation of the embryos shortly but must wait till the female monkeys are at exactly the right stage of their oestrous cycles.

However, another group working with cloned rhesus monkeys said that although they were able to keep the embryos alive in vitro they were not able to achieve pregnancy at implantation. Their research suggests that this was because the cloning process had disrupted the organization of the chromosomes that carry the animals’ DNA.

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