Customized Dogs

Scientists in China are reportedly using gene editing in dogs – a first step in creating customized pets? The first DNA-modified canine is a beagle with twice the normal muscle mass, giving it stronger running ability for hunting, military and police applications. Other institutions have created miniature pigs (which sell for up to $1600) and monkeys to be used as models for studying human diseases.

A method known as CRISPR-Cas9 was used to introduce the DNA-snipping enzyme and a guiding molecule into the DNA of 65 dog embryos. The goal was to delete or damage a gene called myostatin, which normally inhibits muscle development. Out of the 27 puppies that were eventually born, only two displayed a disruption in the myostatin gene. In one of those, the disruption was complete, giving the female puppy known as Tiangou (named after the “heaven dog” in Chinese myth) thigh muscles that were clearly larger than any of her littermates.

The ultimate objective is to use the technique as a way to generate new disease models for biomedical research. But, while gene-edited pets may put a friendly face on the technology, many researchers fear that alteration of dogs and other large animals could open a Pandora’s Box of using the technique on humans.