Researchers in China have used gene editing to delete myostatin in beagles, creating ones with twice the usual amount of muscle mass, according to MIT's Technology Review.
As they report in the Journal of Molecular Cell Biology, researchers led by Nanjing University's Xiang Gao used the CRISPR/Cas9 genome editing approach to knock out myostatin in two beagle puppies. The researchers transferred 35 zygotes injected with a mix of Cas9 mRNA and MSTN sgRNA into 10 female dogs, eight of which carried their pregnancies to term and gave birth to 27 puppies. But only two puppies, called Tiangou and Hercules, had disruptions in both copies of their myostatin gene.
In Hercules, the researchers say that the knockout was incomplete as a portion of his cells still produced myostatin, but Tiangou had complete knockout of her myostatin.
Tech Review notes that the myostatin gene is naturally lost in some whippets as well as in a breed of cattle, and that it has occasionally been reported to be lost in some people.
Gao and colleagues say in their paper that they plan use genome editing to develop dog models of disease. Co-author Liangxue Lai from the Guangzhou Institutes of Biomedicine and Health tells Tech Review they have no plans to breed the dogs as pets. Tech Review adds, though that other groups could — a BGI team, after all, has developed miniature pigs through gene editing to sell pets.