Edited by Sophia Savva
In a paper published on January 24 in the journal Cell, researchers from Shanghai claim to have, for the first time ever, successfully created cloned primates using Somatic Cell Nuclear Transfer (SCNT). If the technique sounds familiar, it might be because you learnt about it in high-school biology: SCNT was the complicated method used to create Dolly the sheep, way back in 1996.
Here’s how it works: the nucleus (which contains all of a cell’s genetic information) of a regular somatic (body) cell from a donor is removed; the nucleus from an egg cell of the same species is also removed. The somatic nucleus is then inserted into the egg, and is programmed to become a zygote nucleus – the egg is now essentially fertilised, with a complete set of DNA – it has all the genetic information necessary to produce a fully functioning organism. This egg is now made to divide until it forms a blastocyst (a group of dividing cells), and then an embryo which is implanted into a ‘surrogate’ mother. She is allowed to give birth as usual, and the idea is that her offspring will have genetic material identical to that of the donor (the provider of the somatic nucleus). In other words, the offspring is a clone.
Since Dolly, SCNT has been used to successfully clone a whopping 23 different mammalian species, including sheep, pig, mouse, cattle and even dog. However, all attempts to clone primates, which are much closer to humans, had failed thus far. The team from Shanghai used new technologies to tweak the SCNT procedure, to improve blastocyst development as well as pregnancy rate of transplanted embryos. The success rate was quite low, however: For SCNT in fetal monkeys, 6 pregnancies were confirmed in 21 surrogates and yielded 2 healthy babies.
Nevertheless, this could have large implications in the science world. Since primates are much more closely related to humans than other mammalian species typically used for research purposes, the creation of these clones could help with research on human diseases. As soon as 5 years from now, monkey clones could be used to investigate genetic maladies such as Alzheimer’s and Parkinson’s.
The ethical issues related to this discovery must be considered, however. In addition to the question of whether it is ethical to use monkeys for research purposes, this technique could (technically) be used to clone humans too. Ethicists are currently engaged in discussing these issues, and there are valid arguments for both sides of the argument.