Almost exactly one year ago, the world met with Hua Hua and Zhong Zhong, the first primates cloned through a technique that can theoretically produce an unlimited number of replicas.
Now, a team of Chinese scientists used the same technique to produce five clones of another monkey, which has been genetically altered to have a disorder with a series of traumatic psychological side effects – and the research is a terrible ethical minefield.
The technique used to clone monkeys is called somatic cellular nuclear transfer and involves replacing the donor egg core with one removed from the cell of another animal.
With Hua Hua and Zhong Zhong, scientists took their donor core from the cells of fetal macaques.
But this time, researchers from the Chinese Academy of Sciences used the nucleus of cells from a genetically modified monkey. Specifically, they used CRISPR-Cas9 to change the BMAL1 gene of the animal, helping them to manage some circadian rhythms in some mammals while still being an embryo.
According to two papers by researchers, both published in the journal National Survey of Science, the procedure worked.
The five newborn monkeys showed a "wide range of phenotypes of disorder in the circus," including reduced sleep, increased nighttime movement, schizophrenia-like behaviors, and signs of anxiety and depression-that are shown in a disturbing video published along with research.
From monkeys and men
While the idea of deliberately subjecting the animals to the psychological stresses described above is problematic, researchers believe that potential benefits for mankind are valuable.
"The disruption of the circadian rhythm can lead to many human diseases, including sleep disorders, diabetic mellitus, cancer and neurodegenerative diseases," Hung-Chun Chang, a researcher, said in a press release. "Our BMAL1-knock out monkeys can be used to study the pathogenesis of the disease, as well as therapeutic treatments."
It is also possible that the cloning of genetically modified animals may in fact reduce the number needed for research.
"Without mixing genetic affiliation, a much smaller number of cloned monkeys carrying disease phenotypes may be sufficient for pre-clinical testing of the efficacy of therapy," says researcher Mu-ming Poo.
At the same time, the research raises a multitude of ethical issues.
One thing is the large number of unsuccessful attempts that precede the birth of these five monkeys to review – 65 surrogate mothers were subjected to embryonic implants, resulting in 16 pregnancies, but only five births.
Then, there is a slow question about whether any knowledge extracted from the research will even translate to humans – many animal studies do not.
"If I was an ethics audit committee, I would be very willing to approve it [this research] because of the incredible damage to the animals, "Bioenergy Carolyn Neuhouse told Gizmodo. "I would expect scientists who propose this research to have very good answers to very difficult questions about their methods and the expected benefits of their research."
READ MORE: Chinese scientists first cloned a genetically modified primate[[[[Science Alert]