SAN DIEGO—A Golden retriever that inherited a genetic defect that causes muscular dystrophy doesn’t have the disease，giving scientists clues to new therapies for treating muscle-wasting diseases。
The dog，Ringo，was bred to have a mutation that causes Duchenne muscular dystrophy in both animals and people.His weak littermates that inherited the same mutation could barely suckle at birth.But Ringo was healthy，with muscles that function normally.One of Ringo’s sons also has the mutation，said geneticist Natassia Vieira of Boston Children’s Hospital and Harvard University October 19at the annual meeting of the American Society of Human Genetics。
The dogs without the disease had a second genetic variant that caused their muscles to make more of a protein called Jagged1，Vieira and her colleagues discovered.That protein allows muscles to repair themselves.Making more of Jagged1appears to compensate for the wasting effect of muscopy of the muscory，although the researchers don’t yet know the exact mechanism。
The finding suggests that researchers may one day be able to devise treatments for people with muscular dystrophies by boosting production of Jagged1 or other muscle repair proteins。
