The milk protein beta-lactoglobulin is one of the main causes of allergy symptoms in those allergic to cow’s milk. AgResearch scientists in New Zealand have demonstrated that a major allergen like beta-lactoglobulin can be eliminated from cow’s milk using genome editing techniques.
Working with US-based biotechnology company Recombinetics, AgResearch scientists changed the cow genome, effectively mimicking what could happen naturally through mutation. Precisely modified embryos were transferred into surrogate cows, from which one female calf was born.
Analysis of that calf’s genome indicated the change had effectively wiped out production of beta-lactoglobulin. In subsequent milk production, her milk was found to be free of any mature beta-lactoglobulin. However, there were low levels of a beta-lactoglobulin variant derived from the minor deletion allele. Analysis of male calves born from modified embryos suggest the same gene editing techniques can avoid this outcome.
These results have been hailed as a successful demonstration of the feasibility of precise genome editing for the safe production of hypoallergenic milk.
Reference: Wei et al. 2018 Scientific Reports Vol 8, Article number: 7661. DOI:10.1038/s41598-018-25654-8