The first genetically identical monkey clones were created in a lab by Chinese researchers from the Neuroscience Institute of the Chinese Academy of Sciences in Shangai, led by postdoctoral fellow Zhen Liu. This represents a technical breakthrough and opens up the possibility of cloning humans.
These two macaque monkeys were cloned using the same technique used to clone the infamous Dolly the sheep in 1996, called Somatic Cell Nuclear Transfer (SCNT). They are called Zhong Zhong and Hua Hua, deriving from the word zhonghua, which basically means “Chinese”. They are eight and six weeks old and are genetically identical, coming both from the same donor culture of fetal monkey cells. This is the first time fully identical developed monkeys are actually cloned.
Even though this method had proved efficient in cloning 23 different mammalian species, such as sheep, mouse, cow, rabbit, cattle, pig, cat, rat and dog, cloning primates was a different issue. The study's paper, published on the science journal Call, states that “previous failure of SCNT appears to be caused by inappropriate reprogramming of the somatic nucleus for supporting the development of transplanted embryos.”
The SCNT technique consists of transferring the cell's nucleus from one animal's cell into another’s egg with its nucleus removed. This nucleus contains the first animal's genetic code, its DNA. Then, the egg is chemically developed and implanted into the mother. Among the steps the scientists had to adjust in order to achieve success was to add the use of fetal cell nuclei, instead of a grown-up monkey.
After the proper technique to clone a primate had been established after 21 attempts and 127 eggs, new questions arose. This represented a big step in genetics which could spark as much controversy as Dolly did, since many people consider this procedure the next step forward towards cloning humans.
The macaque monkey is a species close to humans, and they are usually used as a model for studying physiological functions unique to primates and developing therapeutic treatments of human diseases. According to the study, but there's no intention to clone humans whatsoever.
“The reason we chose to break this barrier is to produce animal models that are useful for human medicine. There’s no intention to apply this method to humans,” study's coauthor Mu-Ming Poo told to National Geographic.
The use of genetically identical animals in research helps to avoid variability factors that could spoil experiments.
However, this will probably spark protests and debates, since cloning animals for research purposes doesn't appeal to an ever larger portion of the population, especially when speaking about a species so similar to us. “I hope that societies in Western countries will realize once we demonstrate the cloned monkeys’ usefulness in curing disease, they will gradually change their mind,” said Poo.
For now, the method is not perfect and will require further research. The authors of the research will keep monitoring the monkeys' health, now still living in incubators.