Transgenic Cow Raises Questions About FDA Approval Process
According to a recent report published in the Proceedings of the National Academy of Sciences, scientists have successfully engineered a transgenic dairy cow that produces milk with decreased levels of β-lactoglobulin (BLG), a major allergen which is not present in human milk. Anower Jabed, et al., “Targeted microRNA expression in dairy cattle directs production of β-lactoglobulin-free, high-casein milk,” PNAS, October 2012. After testing their hypothesis in a mouse model, New Zealand researchers apparently used a technique called RNA interference to effectively silence the gene responsible for expressing the BLG protein in cow’s milk. The resulting transgenic calf reportedly yielded milk with “no detectable BLG protein” but “more than twice the level of the casein proteins that also normally occur in cow’s milk.”
“People have long looked into reducing this enigmatic protein, or completely knocking it out, because there has been no definitive function able to be assigned to it. So, we developed this scientific model to investigate the effect of knocking BLG protein out on the composition and functional properties of milk, and to determine whether the absence of BLG produces cow’s milk that is hypoallergenic,” said one of the study’s authors in an October 2, 2012, AgResearch press release. “We now want to breed from Daisy and determine the milk composition and yield from a natural lactation. We also want to investigate the origin of Daisy’s taillessness [sic], a rare congenital disease in cows.”
Meanwhile, the report has prompted further public discussion about the Food and Drug Administration’s (FDA’s) plans to regulate genetically modified (GM) animals. As Rosie Mestel recounts in an October 1, 2012, Los Angeles Times article, the agency’s delay on the first application for fast-growing Atlantic salmon created by AquaBounty Technologies “has had a chilling effect on animal biotech efforts” ranging from environmentally friendly pigs to poultry and livestock that would require fewer antibiotics or other medical interventions.
“The process for getting government approval to sell food derived from genetically engineered animals appears to be at a hopeless logjam,” writes Mestel, citing many projects that have dried up or relocated for lack of both regulatory and financial support in the United States. Additional details about a coalition of industry and scientific groups concerned about FDA’s progress on the AquaBounty salmon decision appear in Issue 404 of this Update.
