Chinese scientists have used the cloning technique that successfully produced Dolly the sheep twenty years ago to clone monkeys, surmounting a technical barrier that now opens possibilities for human cloning.
Two identical long-tailed macaques, now named Zhong Zhong and Hua Hua, were born eight and six weeks ago, respectively. This makes them the first primates ever to have been cloned out of a non-embryonic cell, Newsweek reports.
The cloning was achieved by researchers at the Chinese Academy of Sciences Institute of Neuroscience in Shanghai through a procedure called somatic cell nuclear transfer (SCNT). This involves transferring the nucleus of a cell – and its DNA – into an egg which does not contain a nucleus.
The researchers say that these results could mean great benefits for medical research by allowing the study of diseases in genetically uniform monkeys. And this also brings human cloning one step closer to reality.
Muming Poo, who helped supervise the program at the institute, said, “Humans are primates. So (for) the cloning of primate species, including humans, the technical barrier is now broken.” Poo added,
The reason…we broke this barrier is to produce animal models that are useful for medicine, for human health. There is no intention to apply this method to humans.
Genetically identical animals are good for research purposes because there are so many factors in genetic diseases that can complicate experiments in non-cloned animals. Cloned animals can be used for things such as new drug tests before clinical use.
The Chinese team went through many attempts, with low success rates, before hitting on the technique of using modulators to control certain genes that were hampering embryo development. It took 127 cells before the two monkeys were successfully created.
For now, the two macaques are being bottle-fed and are growing normally. The researchers said that more monkeys will be born from cloning in the next months.
The study was published in the journal Cell.