Scientists edit genes to breed colorful sheep

A team of Chinese scientists in the Xinjiang autonomous region have successfully used a gene editing technique to breed five sheep with colored fleece.

The researchers in Urumqi used a technique called CRISPR-Cas9, also known as the "molecular Swiss army knife", to alter the color of the animals' coats on a genetic level - paving the way for colored wool that does not need to be dyed.

Currently living at the Xinjiang Academy of Zootechnical Science, the sheep have eye-catching fleeces, with some resembling cows, others Dalmation dogs and one looking like an unstirred cappuccino.

"The lambs, born in March, have become our pets," said Liu Mingjun, head researcher.

According to Liu, this is the first time that scientists have altered the color of a large animal's coat using the CRISPR-Cas9 technique. Previous experiments on color alteration were limited to mice.

The breakthrough means that consumers in future will be able to purchase colorful wool products that do not need to be dyed, Liu said, while other applications include using the technique on pets, making their fur color customizable.

Liu's team selected ASIP, a key gene affecting the color of a sheep's fleece, to edit for the desired colors.

The CRISPR-Cas9 technique was invented in 2012 at the University of California, Berkeley in the US. It allows scientists to selectively trim away unwanted parts of an animal's genome and replace them with new strings of DNA.

"The application to large animals indicates more strains of animals, not limited to livestock, will be developed via the approach, with different patterns not limited to coat colors," Liu said.

"Compared with traditional gene mutation approaches in which researchers take decades to breed a new strain, gene editing is more much effective."

Liu's team used the technique last year to breed 38 sheep that had enhanced muscle and wool growth.

(China Daily 06/24/2016 page6)