China looks at mass breeding of designer sheep

BEIJING - Chinese scientists claimed to have developed a new technique of genetic engineering that may lead to mass breeding of transgenic sheep.

The new “lentivirus” technique is more efficient and predictable than traditional method and it would give China an edge in breeding genetically altered sheep and establishing a new transgenic sheep species, said Liu Mingjun of the Xinjiang Academy of Zootechnical Science, who led the research.

Between February and April, 118 pregnant ewes carrying transgenic embryos delivered 162 lambs. Of the newborns, 92 were transgenic lambs, a record 56.8 percent hike in the rate of transgenic efficiency, Xinhua reported.

In traditional methods, the transgenic efficiency — proportion of transgenic lambs to the testing of newly born — ranges between one percent to five percent.

Earlier, scientists of Roslin Institute of Edinburgh University made seven transgenic lambs with somatic cell cloning in one experiment, with 2.25 percent efficiency.

Liu’s research team employed lentivirus technique to have 473 transgenic embryos transferred into 255 ewes. And 118 ewes got pregnant.

Liu said that the technique would require scientists to inject the cloned exogenous genes related to muscle- and wool-growth into lentivirus vectors.

The vector, a molecule invisible to naked eyes, can facilitate the integration of the desired genes with the host chromosome and thus improve the success rate of transgenic breeding, he said.

So far, 61 of the 92 transgenic sheep have survived.

Liu said that his research is aimed at enhancing sheep’s muscle growth and increase the productivity and quality of sheep wool.

“The next thing we will do is to monitor the growth of the transgenic sheep and conduct in-depth analysis and examination to screen out the best animals for the cultivation of a new species,” he said.