The cloned monkeys could mark the beginning of a new era in studying human diseases. Why does, Militiov, the biotechnologist that cloned primates for the first time, fears private attempts to clone humans?

In the latest edition of the prestigious Journal Cell, an article was published (see HERE) – very important in our opinion – that reported the birth of two healthy monkeys, Zhong Zhong and Hua Hua, produced by cloning at the Institute of Neuroscience, Shanghai. This is the first time that this has been achieved.


The technique used was somatic cell nuclear transfer (SCNT), the same one used to create Dolly the sheep  20 years ago. Since then, 23 species of mammals have been cloned, such as sheep, mice, cattle, pigs, cats, rats, dogs and others. However, these two cloned primates are not the first obtained to date. The first, which was born in 2002, was produced at the Oregon Regional Primate Research Centre by Shoukhrat Mitalipov’s team. On that occasion, however, the embryonic division was used, so only four clones could be created at a time; in contrast, with the technique now proposed (SCNT), a larger number of cloned animals can be created.

This time, the researchers used adult cells from monkey fetuses. Six pregnancies were achieved in 21 surrogate monkeys, with two healthy primates eventually being born. Genetic analysis in both animals confirmed that the nuclear and mitochondrial DNA of the clones was the same as the DNA from the adult nucleus donor cell and the donor oocytes used to obtain the mitochondria.

According to Xiong Zhi-Qi, a neuroscientist who studies brain diseases at the Institute of Neuroscience in Shanghai, and who did not take part in these experiments, the research published in this article “could mark the beginning of a new era in biomedical research” (see HERE ).

Why can cloned monkeys represent an advantage for studying human diseases?

Furthermore, this technique opens an objective possibility of studying human diseases, especially genetic ones, because the cloned monkeys could be a very valid instrument for biomedical, primarily pharmacological, experiments. To date, in experiments in which non-cloned monkeys are used, it is difficult to determine whether the possible differences in outcomes obtained between treated animals and the control group are due to the treatment evaluated or to genetic variations between both groups. That is to say, there are biases that are difficult to avoid. In this respect, Terry Sejnowski, a renowned neurobiologist at the Salk Institute in La Jolla, California, says that “working with cloned animals greatly reduces the variability of the genetic background, so fewer animals are needed”.

Primate-cloning technology will soon be combined with gene-editing tools”, which will open a new avenue to study of diseases

Additionally, Chang Hung-Chun, also a member of the Institute of Neuroscience in Shanghai, says that “primate-cloning technology will soon be combined with gene-editing tools”, which will open many possibilities for the study of diseases, because the donor cells could be genetically modified and then injected into the eggs that are to give rise to the cloned embryos. In this respect, Mu-Ming Poo is expecting the birth of cloned monkeys whose genome has been edited to study Parkinson’s disease.

From a bioethical point of view, animal cloning presents no objective difficulties, providing that the general rules for this type of research are respected. The only ethical difficulty that might present, although hypothetical, is that this research, via a slippery slope, could encourage human cloning, because according to Mu-Ming Poo, director of the ION (see HERE) and study co-author, “technically, there is no barrier to human cloning”, although he says that  the ION is interested only in making genetically identical monkeys.

Mitalipov, the first to clone primates, also fears that, although attempting to clone humans is legally banned, it could be carried out in private institutions, because in some countries, like the United States, cloning is not banned at all. Poo, meanwhile, believes that only strict regulation of cloning can solve the problem and that, for this reason, “society has to pay more attention to this”.






Justo Aznar.

Bioethics Observatory – Institute of Life Sciences