Scientists claim to have successfully cloned two long-tailed macaques using the same technique that produced Dolly the sheep over two decades ago. Are humans next?
Not your average pair of twins [Photo by Xinhua/Jin Liwang via Getty Images]
Long-tailed macaques Zhong Zhong and Hua Hua, named after the Chinese word “Zhōnghuá”, which means “Chinese nation”, are genetically identical. However, they’re not your average, everyday twins. For one thing, they were born two weeks apart. For another thing, they’re actually clones—the first primates to successfully be cloned using non-embryonic cells.
However, this isn’t the first time that a primate was successfully cloned, period. A method called embryo splitting enabled scientists to clone a rhesus monkey named Tetra back in 1999. This is a simpler cloning method that entails splitting embryos in much the same way that twins are produced.
The process that produced Zhong Zhong and Hua Hua, as well as the famous Dolly the sheep back in 1996, is a much more complicated process called somatic cell nuclear transfer (SCNT).
The first primates to be cloned using SCNT [Photo by AP]
SCNT has actually been utilized many times to clone various animals like mice, rabbits, dogs, cows, and pigs. However, the process has repeatedly failed to clone primates. SCNT involves taking the nucleus from an egg cell belonging to one individual, then replacing it with the nucleus of a body cell belonging to a second individual. This modified egg cell is then implanted into a third individual and develops into a clone of the second individual.
Zhong Zhong and Hua Hua are the products of groundbreaking research. [Photo by Qiang Sun and Mu-ming Poo/Chines/PA]
A new study details how researchers modified the SCNT process with new technology that was involved in cell fusion and the transfer of nuclei. It took three years to develop this procedure, eventually leading the researchers to discover that using cells from fetal tissue yielded better results than using adult cells. The researchers were able to produce 79 embryos, which they then implanted in 21 surrogates. A total of six pregnancies occurred, resulting in the birth of Zhong Zhong and Hua Hua.
The researchers admitted to having gone through several failures before finding a method that worked. Other scientists think that the procedure, though it has managed to successfully produce two live babies, still needs more work before it becomes a more common practice. After all, given the numbers, the procedure actually has a very limited success rate.
Researchers say that the two cloned monkeys are growing more active everyday, just like human babies. [Photo by Reuters]
Of course, as with any case involving cloning, there is a question of ethics. One ethical concern is the quality of life of these cloned monkeys. Some have pointed out that cloned animals do not live long, and their short lives are full of suffering. Also, there is the question of the product of failed cloning attempts: these are live animals, and is it humane to have created them only to have them live a short, brutal life?
There’s also the question of human cloning. If cloning primates using SCNT is possible, would it be possible to clone humans using the same technique as well? The study’s authors stress that they have no intentions of trying to do so. However, they do want their research to add to the discussion on laws and regulations that would need to govern cloning.
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