Genetically Modified Monkeys May Help Scientists Understand Brain Disorders Like Autism

For human brain research, crab-eating macaques and marmosets are the animals of choice for many scientists. They are smaller and easier to take care of than chimps, yet their brains are much more similar to human brains than those of mice. That's why geneticists are attempting to genetically engineer monkeys with symptoms of autism and schizophrenia to better understand those disorders.

According to The Atlantic, chair of neuroscience at MIT Guoping Feng has been studying genetically engineered mice with "knocked out," or disabled genes that may, when mutated, cause autism. But it's difficult to compare an autistic mouse with an autistic human, as the different species' have different bodies, brains, genes and habits.

Macaques and other monkeys are similar to humans, so they are subject to scientific research on brain disorders. Kevin Frayer/Getty Images

Instead, Feng is using the promising new gene-editing technology called CRISPR on primates. CRISPR is notoriously fast and easy to use, and can "cut and paste" whatever genes a scientist wants onto an embryo with precision.

Feng regularly travels to the other side of the world in order to access primate research facilities that would be too costly and controversial in the United States where he lives, The Atlantic reports. In China, scientists have already genetically engineered monkeys with a variety of diseases.

In the U.S., animal testing is on the rise. However, using nonhuman primates for research is more controversial in the United States, with organizations like the Humane Society of the United States and the American Anti-Vivisection Society working to oppose and end the practice. After chimpanzees have served their purpose in research, they are supposed to go to expensive sanctuaries, whereas lab workers usually simply euthanize other animals when the experiment is over.

China is home to the world's first monkeys cloned with the same technique that was used to clone Dolly the sheep. Some scientists believe that experimenting on genetically identical, cloned monkeys is the future of scientific research. As, by definition, a cloned monkey will have the same DNA as its gene donor, scientists don't have to worry that variation in test results are just due to genes—those variations are more likely to be a result of treatment.

Since CRISPR affects the germline of an organism, it's possible for those animals to pass that trait down to their offspring. Furthermore, if a monkey has a gene that causes symptoms of schizophrenia, autism, Parkinson's or another disease, any clone of that monkey would have that gene as well. Having a consistent population of genetically consistent animals should make research into brain disorders easier and more fruitful.