Genetically modified ‘super livestock’ to meet food shortage
ROBERT MENDICK and VICTORIA WARD
Elite species of pigs, goats and cattle could be developed after scientists announced a controversial breakthrough in genetic engineering.
Experts from the Roslin Institute at the University of Edinburgh have created livestock that can serve as “surrogate sires”, male animals that produce sperm carrying only the genetic traits of donor animals.
They said it could speed the spread of desirable characteristics in animals and improve food production for a growing global population.
The livestock could live longer as they would have a better life with less disease and could produce tastier meat.
Researchers said it could even create an option for genetic conservation of endangered species.
Prof Bruce Whitelaw of the Roslin Institute, famed for creating Dolly, the world’s first cloned sheep, said: “The intent of surrogate sires is to be a novel breeding tool for use in livestock production that hopefully we’ll allow for the cheap efficient and widespread dissemination of desirable or what some may call elite or superior genetics. “It removes the need for artificial insemination or any surgical intervention. Your animals become an artificial insemination unit.”
However, critics say genetically modified (GM) breeding is likely to harm animals and create so-called Frankenstein breeds that are too big or produce more milk than they should.
Starting on mice, the research team took animal embryos and then knocked out the gene specific to male fertility, creating males that were infertile.
The male animals — first the mice and then pigs, goats and cattle — grew up sterile. The infertile animals then received transplanted sperm-producing stem cells from surrogates.
The sterile animals, healthy according to the researchers in every other way, then began producing sperm derived from the donors’ cells.
The mice, according to the researchers, “fathered healthy offspring” that carried the genes of the donor mice. The larger animals have yet to be bred.
“With this technology, we can get better dissemination of desirable traits and improve the efficiency of food production,” said Jon Oatley, lead researcher and a biologist at Washington State University. “If we can tackle this genetically, then that means less water, less feed and fewer antibiotics we have to put into the animals.”
The scientists used a “geneediting” tool — called CRISPRCas9 — to produce mice, pigs, goats and cattle that were then born without the NANOS2 gene, which meant they grew up sterile.
The scientists admitted that although they can now produce “surrogate sires”, the technology could not be commercialised because of current regulations that prevent gene-edited animals entering the food chain.
Dr Helen Wallace, of GeneWatch UK, was critical of the research to make animals infertile and then fertile again.
Dr Wallace said: “The process of producing surrogate sires is likely to harm animals, as genetic engineering involves many failed attempts.” —