Chinese geneticists have been criticised after cloning five monkeys "deliberately edited" to be mentally ill.
Welfare concerns were expressed as genetically identical macaques showed signs of depression, reduced sleep and schizophrenia-like behaviours.
They were born with an inoperative BMAL1 gene, which regulates the circadian rhythm and was altered using the CRISPR "molecular scissors" editing technique. Published in the National Science Review, the experiment by the Chinese Academy of Sciences Institute of Neuroscience could enable teams to test drugs for eventual use on humans with neurological conditions.
But Dr Julia Baines, of the campaign group PETA UK, said: "Genetically manipulating and then cloning animals is a monstrous practice that causes animals to suffer." The academy defended the practice, saying cloning animals engineered to be ill would enable the number of primates used in the laboratory to be significantly reduced.
AdvertisementAdvertise with NZME.
Poo Mu-Ming, co-author of the study, said: "Without the interference of genetic background, a much smaller number of cloned monkeys carrying disease phenotypes may be sufficient for preclinical tests."
Sun Qiang, who led the research, said using cloned monkeys for medical research could improve the speed of drug development. "When they develop a new drug, they need to conduct a large number of animal tests to evaluate performance and adverse effects," he said. "The differences between individual animals could severely affect the reliability of these results."
In January 2018 two different monkeys became the first primates to be cloned, a development that, it was argued, opened the door to human cloning as the species shared 95 per cent of it genes with humans.
In November, He Jiankui, another Chinese researcher, said he had created the world's first genetically edited babies using similar techniques. He was roundly condemned by fellow scientists and the Chinese Government.