In 1996, after the birth of Dolly the sheep, the scientists all over the world have tried to use the same method on various animals including cats, dogs, rats, and cattle. However, none of them was able to succeed in creating the clone until now. A new study published by a team of researchers at the Chinese Academy of Sciences Institute of Neuroscience revealed that they have found a way to tweak the Dolly cloning technique and will make it work in the primates as well. Their efforts have resulted in the birth of two cloned female macaques, named Zhong Zhong and Hua Hua.
The technique used in the cloning of Dolly was somatic cell nuclear transfer. It involved replacing the nucleus in a donor egg with a nucleus which is taken from the cell of a different animal. Scientists use an electric current to make the egg believe that it has been fertilized. After that, it will develop into an embryo which can be implanted into a surrogate for gestation. The animal which will be born from the pregnancy will be a genetic copy of whatever animal’s nucleus was donated.
In primates, the process failed at the blastocyst stage of the embryonic development. To get rid of this hurdle, the team added two new elements to the usual collection of nutrients and growth factors which are typically introduced in the embryos before the surrogate implantation. The new elements, a compound called trichostatin A and messenger RNA. It helped the DNA directly to grow properly by prodding hundreds of genes necessary for successful embryonic development into action.
The technique was tested using cells from both adult and fetal macaques. The attempts made using cells from adult macaques produced two live animals but they did not survive very long after their birth. One of them didn’t even have its body developed completely. The researchers decided to use the cells from fetal macaques. They implanted 79 of those embryos into 21 surrogates. Among those 21 surrogates, only 6 became pregnant. And from those 6 pregnancies, only Zhong Zhong and Hua Hua were successful live births. Even though the number is not very high, still this is the most remarkable progress.
This Chinese team is not the first one to clone a primate. However, they are the first one to do so by using the modified version of the Dolly method. This has been a goal of researchers for a very long time since it offers a big advantage over the previous method, which involved splitting an embryo after fertilization. While the technique can only produce four cloned animals maximum, the Dolly method can produce an unlimited number of clones. The ability to create more sets of genetically identical clones will be very valuable for medical research.
These macaques are closer to humans genetically than the mice. So the insight scientists can get by testing on them can be more easily translated to humans. Using cloned animals instead of those that are related to each other also add a level of precision to the testing by creating a true control. Complete groups of macaques which have genes linked to Alzheimer’s, Parkinson’s disease, or cancer can also be created in the lab. Doctors can test different treatments on animals and can get an accurate idea of how the patients will respond to a specific medicine. They can also make minor changes in the genes of one animal to see how the results will be as compared to the rest of the population.
Some people have also concerned that the successful cloning of macaques puts the scientists’ one step closer to humans cloning. However, the co-author of the research told that they have no intention of applying the method they developed to humans. They also do not have any incentive to do so. Peter Andrews, a professor at the University of Sheffield said, “It could be a step towards human cloning, but why would you do it. In terms of human biology, it’s illegal to clone a human in Britain and many other countries, and I don’t think anyone would rationally want to do it.”
The Chinese team succeeded in developing the technique but their success rate is very low. Seeing that it can be assumed that the scientists are still not at that point where they can easily create clones in the labs. However, it should also be kept in mind that if the group has found the procedure then Zhong Zhong and Hua Hua will be going down in history as cloning achievements in the future just like dolly is today.
The thing to remember here is that we have broken the barrier to cloning humans. While the international and national regulations prevent the human cloning, no one is going to follow the law in this case. Something that should be realized here is that scientific advancements are not determined by the fact that what we should do but instead they work on what can we do. Laws can try to ban whatever science they want, but they cannot stop anything from happening. It might be the time when we consider the application of regulation instead of prohibition.