Many animals have been cloned since Dolly captured the world's attention in 1996, and several documents suggest earlier examples, but primates have presented formidable resistance to scientists... until now. A team of researchers from the Institute of Neuroscience at the Chinese Academy of Sciences presented to the world the cloning of two macaques, Zhong Zhong and Hua Hua, eight and six weeks old respectively. This once again opens the debate on human cloning, while anticipating new treatments for diseases.
The Legacy of Dolly
Let's do a bit of memory: Dolly the sheep was born on July 5, 1996. Despite having lived for six and a half years (until February 14, 2003) when a life expectancy of 11 or 12 years was calculated, all subsequent analyses concluded that her death (euthanasia decided in the presence of a lung adenocarcinoma very common in sheep) was not related to her condition as a clone. The world was never the same on a genetic level with the birth of Dolly, and many scientists concentrated their firepower on different cloning techniques, which have already produced a wide number of animals, some of them extraordinarily expensive (a polo horse was sold for 800,000 dollars). Today, cloning returns to the headlines of world media with a surprising advance: A group of Chinese scientists successfully cloned two rhesus macaques.
Why Is It So Surprising?
First, the researchers from the Institute of Neuroscience at the Chinese Academy of Sciences adopted the same technique applied with Dolly, the so-called somatic cell nuclear transfer, with the difference that this time they used fetal cells, whereas in Dolly's case they were adult cells. And second, primates are historically resistant to all cloning processes. The only previous successful case is that of Tetra in 1999, another female rhesus macaque created from the division of embryos, also known as creation of artificial twins, something considered "semi-cloning."
The two macaques, Zhong Zhong and Hua Hua, are eight and six weeks old, and are in good health. Both are the result of a long effort, and the scientists had to struggle with a very poor efficiency rate. From a total of 127 "eggs," only these two macaques emerged. Another conquest of Chinese genetics, which is also advancing rapidly in the application of CRISPR for the treatment of human diseases.
