Chinese Researchers Use Genetic Modification to Make Buff Beagles

Scientists have genetically modified a dog, specifically a beagle (though not this one), to be twice as muscular as an ordinary one. Mike Segar / REUTERS

Chinese scientists have created a genetically modified beagle that has roughly twice the muscle mass of an ordinary one. The researchers created the buff beagle by deleting a gene called myostatin that normally limits the amount of muscle the body can create, MIT Technology Review reported.

The dogs have "more muscles and are expected to have stronger running ability, which is good for hunting, police (military) applications," Liangxue Lai, a researcher at the Guangzhou Institutes of Biomedicine and Health, told the publication.

The scientists say they don't intend to use the technique to modify pets. Their plan, they've said, is to genetically alter dogs to better understand human disease. They are working on creating dogs with genetic mutations mimicking those found in Parkinson's and muscular dystrophy. "The goal of the research is to explore an approach to the generation of new disease dog models for biomedical research," Lai said. "Dogs are very close to humans in terms of metabolic, physiological and anatomical characteristics."

The dog on the left is a so-called "bully" whippet, which has a mutation in which the myostatin gene is deleted, making the animal extra muscular. Scientists have figured out how to knock out this gene using a method called CRISPR. PLOS ONE

The scientists intentionally created the muscled dogs by introducing a DNA-cutting enzyme that knocked out both copies of myostatin, although only one of the 65 embryos they edited made it to birth with the desired muscular phenotype, according to the study describing the findings, published this month in the Journal of Molecular Cell Biology. The research could have application for scientists who are already trying to block myostatin expression, which leads to muscle loss in people with Duchenne muscular dystrophy, Tech Review reported.

The scientists used a new technique called CRISPR to create the modification. That method allows the precise manipulation of genomes, and many have voiced fears that it could be used on humans. In April, a Chinese team reported using CRISPR to successfully modify the genes of a fertilized human embryo to correct a defect that causes a blood disease called beta-thalassemia.