An inherited form of blindness – directly comparable to a common inherited optic nerve disease in humans – has been discovered in rhesus macaques.
The work could lead to a better understanding of autosomal dominant optic atrophy (ADOA) and potentially to new treatments.
ADOA affects about three in 100,000 people worldwide, causing progressive vision loss and eventual blindness. People with the disease develop blind spots, or scotoma, and there is no available treatment. Many patients are diagnosed between the ages of 10 and 30 and it is, therefore, a significant cause of vision loss in children.
In humans, ADOA is related to mutations in a gene called OPA1, which affects mitochondria.
Rhesus macaques and other non-human primates have a very similar eye structure and vision system to humans. Professor Sara Thomasy and colleagues at the California National Primate Research Center at the University of California, Davis, in the United States, found that some of the monkeys at the research centre had a spontaneous mutation in OPA1 that leads to changes in the eye very similar to those in people with ADOA.1
A Chance Project
The discovery came about because first author Tracy Jaggers, then a veterinary student was planning a summer project with Prof Thomasy, but had to switch projects due to the COVID-19 pandemic.
“We had planned this wonderful behavioural study out at the primate centre, and then COVID hit and obviously she couldn’t come and do the project. So I said, well, I have this interesting data set of monkeys with this mutation,” Prof Thomasy said.
The mutation had been previously identified in a DNA sequencing project at the centre. Prof Thomasy said she didn’t expect much from Ms Jaggers’ project, and expected it to be a negative study.
Using imaging techniques from human ophthalmology, Ms Jaggers and Prof Thomasy found that an animal with eye abnormalities also carried a copy of the OPA1 mutation. With that data, they were able to get a grant to expand the research and set up a breeding colony.
The researchers can now look at how the disease progresses over time and how it differs between animals with a single copy or two copies of the OPA1 mutation. The rhesus macaque could be a model to study gene therapy to prevent ADOA, or to test treatments that could slow or block progression in humans, Prof Thomasy said.
Reference
- Fell A, Identifying genetic causes of blindness in people and macaques, UC Davis News, available at: ucdavis.edu/news/identifying-genetic-causes-blindness-people-and-macaques
