Researchers at the Chinese Academy of Sciences Institute of Neuroscience have successfully cloned two monkeys using the same approach used to clone sheep over 20 years ago, according to Reuters. The development marks a breakthrough – over 20 animal species have been cloned using the technique since Dolly the Sheep in 1996, but until now, the technique had always failed with primates.
The process is called somatic cell nuclear transfer (SCNT). Scientists transfer the nucleus of a cell, which includes DNA, into an egg from which the nucleus has been removed.
While the breakthrough would seem to clear one hurdle on the path to cloning humans, researchers say that was not their primary goal in the endeavor. According to Muming Poo, who supervised the project:
“Humans are primates. So the cloning of primate species, including humans, the technical barrier is now broken. 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.”
According to Qiang Sun, from the Institute of Neuroscience, genetically identical moneys will help scientists study diseases with a genetic component, such as cancer and immune or metabolic disorders.
“There are a lot of questions about primate biology that can be studied by having this additional model,” said Sun.
According to Professor Robin Lovell-Badge from London’s Francis Crick Institute, the approach is “a very inefficient and hazardous procedure” that is “not a stepping-stone to establishing methods for obtaining live born human clones.”
The monkeys, Zhong Zhong and Hua Hua, are the first primates cloned using the SCNT technique. However, a rhesus monkey born in 1999 was the world’s first cloned monkey. In that instance, an embryo was split to create two identical twins. The process did not involve the more complex use of DNA transfer.
The study, published in the journal Cell, details almost 80 attempts by the researchers. Two monkeys were cloned from another type of cell but failed to survive.
“We tried several different methods, but only one worked. There was much failure before we found a way to successfully clone a monkey,” according to Sun.
The development is also an example of China’s leading role in the field. Three years ago, Chinese researchers Sun Yat-sen University in Guangzhou performed the first experiment to edit DNA in human embryos. Despite widespread debate over the ethics of such experiments, similar research has now been performed in the US.