AUG 30, 2019 3:00 PM PDT

Mutant sheep bred to help scientists understand rare child brain disease

WRITTEN BY: Nina Lichtenberg

Scientists at Edinburgh University’s Roslin Institute have created a flock of sheep that carry the gene for a heritable brain disorder in humans called Batten disease. The condition usually starts in childhood and is fatal – patients often pass away within a few years of diagnosis.

Batten disease is inherited from two carrier parents, meaning that each parent must possess a rare recessive gene mutation. The mutation interferes with lysosomes, which dispose of cell waste. Children with two copies of the gene suffer from vision loss, impaired cognition, and limited mobility; followed by seizures and premature death.

Researchers acknowledge that the approach is controversial because it requires breeding animals that will succumb to the disease, but they emphasize that the ultimate goal is to treat the condition in humans. “We have deliberately re-created the condition in a large mammal because sheep have a brain of a similar size and complexity to that of a child,” said Dr. Tom Wishart, project leader. “That means treatments we test on them are much more likely to be relevant to humans than those tested only on cell cultures or mice and rats.”

Dr. Wishart and colleagues used the novel gene-editing technique CRISPR-Cas9 to insert the Batten disease gene CLN1 into the sheep genome. “We collected sheep embryos from the abattoir,” Wishart said. “Then we fertilized them and added CRISPR reagents to alter their genetic structure before implanting the embryos into a surrogate sheep’s uterus.”

Three sheep were born and showed many symptoms of Batten disease, including changes in behavior and brain size. “The progress of the disease in sheep closely resembled its development in children,” said Wishart.

Researchers are now working on treatments for Batten disease, including gene therapy in which healthy genes are inserted into the mutated genomes. These techniques are primarily being developed using cell culture and research on rodents. If scientists do not use these few larger animals to refine discoveries, all the early work could lose its translational value - it would be wasted.

“It is a terrible necessity – to reproduce such a condition. However, we are talking about using maybe only 10 or so animals for this research with the ultimate aim of finding treatments that could add years to the lives of young patients,” said Wishart.

Source: The Guardian

About the Author
You May Also Like
FEB 27, 2020
Cell & Molecular Biology
FEB 27, 2020
Caloric Restriction Changes Gene Expression, Reduces Inflammation
New research has added to the evidence that suggests that dietary restriction has health benefits....
MAR 06, 2020
Cardiology
MAR 06, 2020
Why Is Good Nutrition Advise So Hard to Come By
Nutrition advice seems to come from everywhere. Exposure to this advice, one is likely to find endless examples of conflicting information. This happens fo...
MAR 04, 2020
Cannabis Sciences
MAR 04, 2020
Smoking Marijuana Could Cause 12 Hour Erections
Smoking marijuana is known to have multiple side effects. From getting the munchies to paranoia and memory problems, it is also usually thought to cause er...
MAR 07, 2020
Cannabis Sciences
MAR 07, 2020
Why Cannabis Makes Some Feel Good and Others Paranoid
Whether or not someone enjoys the effects of cannabis tends to depend on how it makes them feel. For example, although for some, the ‘high; feels gre...
MAR 08, 2020
Cardiology
MAR 08, 2020
Cashier and Healthcare Jobs Increase Risk of Heart Problems in Women
Stress has long been known to be a major risk factor for developing heart disease. Now, researchers from Drexel University in Philadelphia have found that ...
MAR 20, 2020
Health & Medicine
MAR 20, 2020
Why Does COVID-19 Kill So Many Older People?
Since early statistics began to emerge from China, it seemed that COVID-19 tended to affect older people more than younger ones. And now, data from Italy i...
Loading Comments...