Genetics research aids scrapie eradication

Scientists with the Agriculture Department's Agricultural Research Service have developed genetic tests to more accurately diagnose scrapie in sheep. Their goal is to eventually eradicate scrapie by selectively breeding sheep less susceptible to the deadly neurodegenerative disease.

According to the ARS, government researchers have amassed a detailed body of knowledge allowing them to test sheep for scrapie susceptibility with great accuracy. With that information, breeders can select less-susceptible sheep and breed more scrapie-resistant flocks.

Scrapie costs U.S. sheep producers an estimated $20 million annually, and its eradication is the industry's top priority.

Genetic predisposition to scrapie is related to variations in amino acid sequences coded within each sheep's DNA. Selective breeding for resistance could one day reduce the genetic risk of developing scrapie and may eventually eradicate it, according to the ARS.

Drawing from a diverse group of U.S. sheep, researchers have resequenced the prion gene, identifying a new genetic variation. This achievement, the ARS states, has improved commercially available genotyping tests and enhanced the government's National Scrapie Eradication Program.

Essentially, this research is improving the speed, cost, and quality of antiscrapie breeding methods.

The scientists have identified and stored DNA from 15 common sheep breeds. This information is freely available to researchers and testing laboratories to facilitate diagnosis and eventual scrapie eradication.