Scientists in China have created two monkeys with customized gene mutations. The successful births of the twin macaques, named Ningning and Mingming, may bring researchers closer to being able to recreate such human diseases as Alzheimer’s and Parkinson’s in primates. This would allow scientists to use primates, rather than rodents, as more realistic models of human illness.
To engineer the monkeys, researchers at Nanjing University and Yunnan Key Laboratory of Primate Biomedical Research in Kunming, China, used a new “gene-editing” technology called Crispr, which allows scientists to insert, delete, or rewrite a specific gene sequence. The technique, which may help usher in a new era of genetic medicine, has previously been used to manipulate the genomes of rats, mice, and zebrafish. But this is reportedly the first time it has been used successfully in primates.
The Chinese researchers altered genes in several fertilized monkey eggs before implanting them in surrogate mothers. (Several surrogates miscarried and some pregnancies are reportedly ongoing.) Newborn Ningning and Mingming have three modified genes: “one that regulates metabolism, another that regulates immune cell development, and a third that regulates stem cells and sex determination,” according to the MIT Technology Review.
The infant monkeys are too young for researchers to determine the physiological and behavioral effects of their mutations, but scientists worldwide are already looking to create their own Crispr-modified monkeys. “Although mice are giving us tremendous insight into basic brain biology and the biology of the disease, there’s still a big gap in between the mouse brain and the monkey brain,” Robert Desimone, director of MIT’s McGovern Brain Institute for Brain Research, told the MIT Technology Review. Not to mention that several drugs that work in mice don’t work in humans.
Researchers also hope that the possibility of using genetically-modified monkeys will encourage more companies to boost spending on drugs to treat neurological disorders, reversing a recent trend of large pharmaceutical companies pulling back from such risky research. They also say Crispr may eventually be used for human gene therapy to treat inherited diseases such as cystic fibrosis and sickle-cell anemia. The ability to alter DNA is also being investigated as a way to make people resistant to HIV.
China’s mutant-monkey breakthrough is controversial among animal rights activists. According to PETA, more than 125,000 primates are kept in U.S. laboratories and used for experiments every year.