Genome editing enabled the creation of calves with resistance to bovine diarrhea virus, or BVDV, a finding reported by the United States Department of Agriculture. BVDV is a global concern because it can trigger reproductive failure as well as gastrointestinal and respiratory symptoms in cattle. While vaccines exist, the virus mutates rapidly, which sometimes limits vaccine effectiveness. In a study led by Aspen Workman and colleagues, the CRISPR-Cas9 genome editing system was used to substitute six amino acids in the bovine CD46 receptor in a calf. This alteration significantly reduced the animal’s susceptibility to the virus and showed no detectable adverse effects in the edited calf.
During the trial, one CD46-edited calf and one unmodified control cohabited with a BVDV-infected calf. Two days later, nasal swabs revealed comparable levels of viral RNA in both the normal and edited calves. Both animals developed fever, yet only the unmodified calves showed cough, rhinitis, and irritation around the nostrils. Blood tests confirmed that while both groups mounted an antibody response to BVDV, the genome-edited calf carried a substantially lower viral load by the time symptoms resolved. The researchers highlight that this approach could pave the way for breeding livestock with enhanced disease resistance, potentially reducing economic losses in cattle populations where BVDV is a persistent threat. Source: USDA and the study team.
The aim behind these findings is to contribute to a broader strategy for improving animal health through precise genetic interventions. By targeting the CD46 receptor, which plays a role in how BVDV interacts with bovine cells, scientists are exploring pathways to limit viral entry and replication without compromising the animal’s overall health. The work underscores the potential of genome editing to complement vaccination programs, offering another valuable tool in the effort to safeguard herds against evolving viral challenges. As the field progresses, ongoing assessment of long-term safety, off-target effects, and ecological implications will be essential to gauge how such technologies can be responsibly integrated into livestock farming. The broader hope is that disease-resistant animals could reduce reliance on chemical interventions and support more resilient agricultural systems.
In related reflections, researchers emphasize that rapid viral mutation presents a continual hurdle for disease control in cattle. Consequently, ongoing research into host receptors like CD46, along with alternative targets and delivery methods for gene editing, remains a priority. The ultimate goal is to establish robust, scalable strategies that improve animal welfare and farm productivity while maintaining rigorous safety standards and ethical considerations. This momentum aligns with a growing emphasis on using genetic insights to foster healthier animals and more sustainable farming practices.