A study that involved creating genetically modified monkeys to see if they demonstrate autistic behaviours may have long-term significance for understanding and treating the condition in humans, researchers say
The study, published online in the journal Nature, involved creating embryos from cells injected with human MECP2. Previous studies have shown that mutations of MECP2 are associated with Rett Syndrome, a severe neurodevelopment disorder in girls, and that its duplication results in MECP2-duplication Syndrome, which is associated with severe autistic behaviours.
In the latest study the genetically modified embryos were implanted in female macaque monkeys producing eight genetically manipulated newborns. The research team from Shanghai Institutes for Biological Sciences then studied the MECP2 transgenic monkeys and compared their behaviour with wild counterparts.
Among their findings were that the transgenic monkeys exhibited a higher frequency of repetitive circular locomotion and showed increased stress responses in threat-related anxiety tests. They also showed less social interaction time with wild-type monkeys and a reduced interaction time when paired with other transgenic monkeys in social interaction tests.
In a further stage of the study the researchers used sperm from male transgenic monkeys to fertilise eggs from female monkeys that had not been genetically modified. The resulting offspring were shown to have the MECP2 gene and they too developed autistic behaviours.
The researchers say that both sets of results indicate the feasibility and reliability of using genetically engineered non-human primates to study brain disorders.
According to a report in Scientific American the research team is now using brain imaging technology to identify where in the brain the MECP2 duplication causes trouble. In future it hopes to use the controversial CRISPR gene editing technique to see whether by removing the duplicate genes the autism-like symptoms can be halted.