Chinese Scientists Develop Gene-edited Sheep to Help Boost Mutton Output

Scientists in China have developed the world’s first myostatin gene (MSTN) edited Chinese Hu sheep, with the hope that the technology will boost mutton output and quality for the national industry.

Researchers at the Jiangsu Academy of Agricultural Sciences have succeeded in breeding five local Hu sheep (湖羊) by editing the MSTN gene, the institution said in a press release.

The MSTN gene provides instructions for making a protein called myostatin, which inhibits the growth and development of muscles.

When myostatin gene undergoes natural mutation, it results in accelerated lean muscle growth. An example of this phenomenon is the Belgian Blue, a breed of beef cattle from Belgium with extremely lean, hyper-sculpted, ultra-muscular physique following the genetic myostatin mutation.

Scientists at the institution employed this naturally occurring mutation in their research and used CRISPR/Cas9 — a new gene-editing technology — to modify the myostatin gene. The editing efficiency turned out to be more than 80%, according to Cao Shaoxian, the lead scientist of the project.

Growth rates of two out of five sheep were significantly higher, with their weights at two months 25% larger than that of their counterparts bred naturally, the Science and Technology Daily reported on Thursday.

The Hu sheep is one of the most distinctive local sheep breeds in China with origins in Mongolia, and is commonly recognized for its thick lambskins. The breed is best known for having high reproductive rates, large litters and being very adaptive to hot and humid climates.

Agricultural experts say the newly-developed technology can help establish optimal breeding programs and reduce the country’s dependence on imports.

Wang Zuli, a deputy researcher at the Institute of Agricultural Economics and Development at the Chinese Academy of Agricultural Sciences, told Global Times that the gene-editing technology could be a way to improve the production of mutton and the percentage of lean meat, provided that there is no major difference between the gene-edited sheep and foreign breeds.

The technology can also reduce the country’s reliance on foreign livestock imports, he added.

SEE ALSO： Gene-edited Babies: Against Natural Evolution and Free Will

In 2019, Chinese consumption of mutton hit 5.27 million tons, higher than the domestic mutton yield of 4.88 million tons, intensifying efforts to boost production. Mutton from Australia and New Zealand accounted for 97.6% of the country’s imports in the same year, according to the Global Times.

Per capita consumption of sheep meat is much higher in China than in other some major markets, including the United States: 3.5 vs. < 0.5 kg (1 kg = 2.2. lbs.). The Chinese do not seem to differentiate between lamb and mutton.