A group of Chinese researchers say that they managed to produce the most realistic representation of an animal affected by autism spectrum disorder. They explained that they genetically tweaked apes to have a gene that is considered to be responsible for the condition in humans. The team currently hopes that the autistic monkeys could help researchers understand biology of autism.
The monkeys display all symptoms of an autistic patient – they show obsessive behaviors, they ignore other monkeys, avoid social confrontation, and they look rather anxious when somebody stares at them.
Nevertheless, researchers acknowledged that the experiment has some limitations since they cannot be quite sure whether the changes observed in the animals’ biology perfectly match the changes in the biology of a human ASD patient.
So far, science hasn’t been able to detect the autism gene, but there are at least 100 probable candidates. Scientists, however, noted that a particular gene called MECP2 may play a crucial part in triggering the disease. They noticed that patients who have a mutation or an extra copy of this gene display many symptoms of autism.
There have been other attempts to induce autism in primates but it is the first time a gene has such an effect on the laboratory animals. For the first time, a research team actually found a link between a specific gene (MECP2) and autistic behavior.
Researchers at the Institute of Neuroscience in Shanghai explained how they achieved the feat. They first paired MECP2 human genes to viruses. Next they implanted the viruses in female macaque monkeys’ eggs. Next, they fertilized the egg cells and implanted them into the animals.
A year later, the offspring showed symptoms of ASD: they behaved strangely, they had hard times in bounding with their healthy peers, and they ran in circles ignoring completely any obstacle in their way. For instance, if another monkey was standing in their way, the autistic monkeys either jumped over the obstacle or simply went around it and continued their circular path.
After several tests, the team observed that all genetically modified monkeys displayed at least one symptom of the disease. Plus, the team learned that the condition was more severe in male monkeys.
Further experiments showed that the genes and behavior can be passed on to second generation. Scientists noted that monkey models are more reliable than previous mouse models, because symptoms are more obvious in apes than in rodents.
Nevertheless, the symptoms displayed by both animal models are less severe than what clinicians usually observe in human patients.
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