Scientists have collaborated to produce the first gene-edited calf that has resistance to bovine viral diarrhea virus (BVDV), which costs the cattle industry billions of dollars every year.
USDA’s Agricultural Research Service (ARS) partnered with the University of Nebraska-Lincoln, the University of Kentucky and industry companies Acceligen and Recombinetics to succeed in the scientific breakthrough.
{{tncms-asset app=”editorial” id=”f856d57a-f652-11ed-9d60-8356279320c6″}}
BVDV has been studied since the 1940s, as it is one of the most significant viruses affecting cattle worldwide. The disease can cause severe respiratory and intestinal diseases, according to USDA. The virus can infect developing calves, causing spontaneous abortions and low birth rates. Infected in-utero calves can survive to birth, but remain infected for life, shedding the virus to other cattle.
“Despite more than 50 years of vaccine availability, controlling BVDV disease remains a problem since vaccines are not always effective in stopping transmission,” USDA said.
Recent scientific advancements (over the past 20 years) have discovered the main cellular receptor CD46 and where the virus binds to the receptor, causing infection in cattle. In the recent study posted in PNAS Nexus, scientists modified the virus-binding site to block infection.
“Our objective was to use gene-editing technology to slightly alter CD46 so it wouldn’t bind the virus yet would retain all its normal bovine functions,” said Aspen Workman, lead author and researcher at ARS’ U.S. Meat Animal Research Center.
Scientists first tested the idea in cell culture, and Acceligen then edited cattle skin cells to develop embryos carrying the altered gene. The embryos were then transplanted into cows to test whether the method could reduce virus infection in live animals.
Success! The first CD46 gene-edited calf, Ginger, was born on July 19, 2021. She was housed with a BVDV-infected dairy calf for a week to see if she could become infected, after which Ginger’s cells displayed significantly reduced susceptibility to BVDV, and there were no observable adverse health effects.
Scientists will continue to observe Ginger and her ability to produce and raise her own calves.
“This proof-of-concept study demonstrates the possibility of reducing the burden of BVDV-associated diseases in cattle by gene editing,” USDA said. “The edited calf also represents another potential opportunity to lessen the need for antibiotics in agriculture since BVDV infection also puts calves at risk for secondary bacterial disease.” — Anna Miller, WLJ managing editor
