It's been about six months since a pair of cloned female macaques were brought into this world by a team of Chinese scientists.
The controversial experiment was the first time a primate has been successfully cloned using a technique known as somatic cell nuclear transfer — the same technique used to clone Dolly the sheep two decades earlier (it’s much harder to do on primates).
The world was introduced to the cloned monkeys, Zhong Zhong and Hua Hua who were six and eight weeks old at the time, in January after they were born at the Chinese Academy of Sciences Institute of Neuroscience in Shanghai.
The successful experiment generated headlines around the world as the breakthrough promised to greatly improve medical research and even open the door to the potential of one day cloning a human.
But nearly five months since the researchers published their paper in the journal Cell, how are the female macaques doing and how will the breakthrough impact on scientific research?
“They are doing very well, now living with other monkeys of the similar age,” said Dr. Mu-ming Poo, director of Chinese Academy of Sciences Institute of Neuroscience who helped lead the project.
The two young macaques show “no sign of any abnormality we can detect,” he told news.com.au over email.
The monkeys are kept in captivity in what he described as “an enriched environment” and researchers will soon begin conducting tests to determine if their development shows any signs of abnormality.
“We will begin behavioral and brain imaging tests soon to monitor their brain and behavioral development,” Dr. Poo said.
Primates are notoriously difficult to clone and while this experiment was deemed a success, it was the result of years of research into the cloning technique which involves removing the nucleus from a healthy egg and replacing it with another nucleus from another type of body cell. The clone becomes the same as the creature that donated the replacement nucleus.
Researchers said it took “many failures” and three years to perfect the procedure.
Critics are quick to point out that cloning has a failure rate of at least 90 per cent, with some labeling the experiment by Chinese researchers as “monstrous”.
However, for many in the field the benefits of being able to produce genetically identical monkeys and not have to rely on primates from the wild for medical research vastly outweighs the ethical conundrum of lab failures.
MORE CLONES ON THE WAY
According to Dr. Poo, scientists at the Shanghai institute are preparing to clone more monkeys to be used in developing treatments for certain brain disorders and other diseases found in humans.
“Yes, more cloned monkeys will soon be produced,” he said. “Some of them will carry gene mutations known to cause human brain disorders, in order to generate useful monkey models for drug development and treatment.”
He wasn’t surprised at the immense global interest the story received after the journal article was published because “producing genetically identical monkeys will have great impact in studying basic science of primates and in developing therapeutics for human diseases”.
“With further improvement of efficiency, we will be able to generate many monkey clones for biomedical research, similar to the mouse strains now widely used,” Dr. Poo said.
It’s important to note that because primates share approximately 95 per cent of human genes and a number of physiological and anatomical similarities, biomedical research currently uses a large number of monkeys, sometimes up to 100,000 annually around the globe.
“This number will be greatly reduced by the use of monkeys with uniform genetic background that reduces the noise in experimental studies,” Dr. Poo said, pointing to the example of testing drug efficacy before clinical trials. “This will greatly help the ethical use of non-human primates for biomedical purposes.”
‘NO JUSTIFICATION’ FOR HUMAN CLONING
Back in January, Dr. Poo told reporters that “in principle” this cloning technique could be applied to humans but he certainly doesn’t believe that will happen any time soon.
“No, there will be technical hurdles to apply the technique to humans, and there is no justification to do this in the foreseeable future,” he said.
He is not aware of any efforts by researchers in China to pursue such a goal, adding “the societal ethics will not allow it.”
This story originally appeared in news.com.au,