A flock of sheep with the Baten disease gene, the deadly brain disorder in humans starting in childhood, has created scientists in Scotland.
The project was designed to test treatments for the disease and was based on the Roslin Institute of the University of Edinburgh, where cloning techniques for Doli sheep in 1996 were used.
Researchers recognize that there are ethical dilemmas in this project as it involves animals programmed to die, but the ultimate goal is to alleviate human pain.
The head of the program, Tom Wisart, said: “It is really awful to have to breed such a treaty, but it is about using 10 animals for a research with the sole purpose of giving many years of life to new sufferers.”
He explained that the selection of these mammals was made because the sheep’s brain is about the same size and complexity as that of the children, so the reactions to the therapies in them were more likely to be similar to humans than if mice or rats were used. .
The disease affects 100 to 150 children and young adults each year in the UK and is inherited by two asymptomatic, healthy parents who carry a rare genetic mutation that affects lysosomal function. Symptoms that occur in children with the disorder are vision loss, cognitive impairment and motor problems, and the disease always leads to death a few years after the first diagnosis.
There are several different types of this disorder, but the one that has the most negative consequences is the genetic mutation CLN1, which was also studied in this study.
Researchers from the Rosslin Institute used the Crispr-Cas9 method (a method by which scientists can directly interfere with DNA and correct, remove or inactivate specific genes) to create the defective CLN1 gene.
The researchers found that, in fact, sheep that had two copies of CLN1 exhibited symptoms of Baten’s disease, which were also observed in children, while those created to have a copy were asymptomatic – such as parents of children with Baten.
Also, according to the Athens-Macedonian News Agency, they are considering many treatments, such as gene therapy, in which they try to replace the mutated genes with healthy viruses.
Weissart explained that sheep, unlike humans, can be studied before the onset of obvious external symptoms, which contributes to understanding the course of the disease, finding invaluable value.