In January 2019, scientists at the institute of neuroscience (ION) in Shanghai reported that gene-editing had been used to disable a gene in macaque monkeys (Macaca fascicularis). One of the genome-edited monkeys was then cloned to produce 5 genetically identical primates [1]. The disabled gene, BMAL1, affects the operation of the animal’s circadian rhythm, or biological clock, to specifically disrupt the animal’s sleep-wake cycle. However, this mutation could induce night-time hyperactivity, hormonal disorders, depression, and even schizophrenia as well [1]. China is currently the only country with the technology to clone primates, and the first two healthy monkey clones had been born in 2018 [2].
The reason for this research stems from the idea that genetically identical primates could provide improved animal models of human disease. These cloned monkeys with circadian rhythm defects may help develop treatments for a range of conditions, such as sleep disorders, diabetes, cancer, and neurodegenerative diseases [1]. This is the first-time researchers have cloned genetically modified monkeys, and this experiment is the first development of a plan to create populations of primates that are said to revolutionise biomedical research [2]. This would allow researchers from around the world who are working on unravelling the mechanisms of complex disorders like Alzheimer’s disease, to access genetically modified monkey clones as their animal models of disease [1]. Using cloned monkeys would allow researchers to administer a variety of doses of the same drug and precisely measure the associated effects, and BMAL1-knockout monkey populations could be used to study disease pathogens as well as therapeutic treatments [2].
While these experiments are legal, it is raising fresh concerns over biomedical ethics, especially as it followed the global scandal of the first genome edited babies the previous year. The twins, known by their pseudonyms, Lulu and Nana, were born in China in October 2018, and He Jiankui was imprisoned for conducting the illegal experiments 13 months later. The lead researcher involved in cloning the macaque monkeys says their work aims to improve the welfare of experimental animals, but various bioethicists and scientists believe that the use of primates in experiments should be a last resort because they have higher levels of cognition than mice and other typical animal models, and there are concerns monkeys will then be used as a default when in many experiments mice would do just fine [2].
It will be interesting to see how legislation around bioethics develops in China following these experiments, and if/how these new animal models of disease will be utilised worldwide.
Mia Georgiou
Bibliography
[1] Institute, W., Institute, W., University, H. and (BCM), B., 2021. Chinese effort to clone gene-edited monkeys kicks off. [online] Nature.com. Available at: <https://www.nature.com/articles/d41586-019-00292-w> [Accessed 11 August 2019].
[2] South China Morning Post. 2019. Chinese scientists create gene-edited monkeys with mental illness. [online] Available at: <https://www.scmp.com/news/china/science/article/2183380/chinese-scientists-successfully-clone-five-baby-monkeys-after> [Accessed 11 August 2021].
