COLUMBIA, Mo., Dec. 8 (UPI) — Researchers at the University of Missouri have developed a pig breed resistant to an incurable disease currently costing farmers $660 million annually.
Swine infected by the Porcine Reproductive and Respiratory Syndrome (PRRS) virus lose weight, rarely reproduce and suffer high mortality rates. But Missouri researchers, with help from scientists at Kansas State University, recently raised a litter of pigs resistant to the virus.
Their success is detailed in a new paper, published this week in the journal Nature Biotechnology.
“Once inside the pigs, PRRS needs some help to spread; it gets that help from a protein called CD163,” study author Randall Prather, an animal sciences professor at Missouri’s College of Agriculture, Food and Natural Resources, said in a press release.
“We were able to breed a litter of pigs that do not produce this protein, and as a result, the virus doesn’t spread,” Prather explained. “When we exposed the pigs to PRRS, they did not get sick and continued to gain weight normally.”
Early in their research, Prather and his colleagues identified the protein CD163 as key in facilitating the proliferation of the PRRS virus. Researchers hypothesized that the proteins work to “strip” or “uncoat” the virus, freeing it to infect the pigs. Gene editing experiments proved their hypothesis correct.
“We edited the gene that makes the CD163 protein so the pigs could no longer produce it,” said study co-author Kristin Whitworth, a research scientist with Missouri’s Division of Animal Sciences. “We then infected these pigs and control pigs; the pigs without CD163 never got sick. This discovery could have enormous implications for pig producers and the food industry throughout the world.”
Researchers confirmed that the newly resistant pig breed did not suffer any negative side effects from the absence of the CD163 protein gene.
Now, researchers are working in coordination with Genus plc, a British biotech company specializing in pig and cattle breeds. They hope to take the breed to market in the near future.