Production of hypoallergenic milk from DNA-free beta-lactoglobulin (BLG) gene knockout cow using zinc-finger nucleases mRNA Reviewed by Jodie Jackson Found within cow's milk, B-lactoglobulin is a primary protein allergen for humans, accounting for 60% of immunoglobulin-E milk allergies. In recent years, there has been a growing interest in the production of hypoallergenic milk free of B-lactoglobulin for consumption. Most commonly in the production of this milk, gene modification techniques such as ZFNs (zinc-finger-nucleases) are used in cows to eliminate the genes responsible for the production of B-lactoglobulin. In accordance with the ethical standards disclosed and presented within in the study, I conclude that this study used ethical means during experimentation to achieve its conclusions. All of the experiments conducted using animals, including the genetically edited/transgenic cows as well as the mice used during the allergen testing were approved by the Animal Experimental Welfare and Ethical Inspection Committee as well as the Institutional Review Boards of China Agricultural University. In design, the study declares it follows the Guide for the Animal Experimental Welfare and Ethical (sic). The gene editing process itself was mediated by ZFN nucleases, in which 64 cow blastocysts were transfected with the enzyme (had their DNA edited) and were then transferred to 16 recipient mothers in which the embryos developed. The researchers had already previously found this method to be the most efficient and successful in previous studies, reducing the general use of live animals in invasive experiments. 16 mothering cows is an appropriate amount and is not wasteful of animal life. To test allergenicity, mice were given varying amounts of the BLG-free milk as well as controls to comparatively judge how immunoglobulin E might react to either milk variant. For the IgE experiment, only 90 rats were used; I consider this not to be an excessive amount, but enough for a sufficiently sized sample. Harmful or painful allergic reactions were never induced in the mice, and instead allergenicity was judged by the level of immunoglobulin E (or IgE), an immune-response-related antibody, detected in their blood samples. For the duration of the experiment, the mice were kept within specific-pathogen-free (SPF) rooms fit with 12-hour light/dark cycles and regular air exchange (15 times an hour), conditions which are humane. Humans which provided their blood serum for IgE binding tests and screenings to further test allergenicity provided their full informed consent and this component of the study was approved by the Institutional Review Boards of China Agricultural University. The participants had their blood drawn and their blood serum reacted with the BLG-free milk to gauge allergenicity, a more ethical and safe approach as opposed to ingestion of the milk, which may have elicited more strong negative reactions. Furthermore, no animal or human deaths occurred within/as a result of this study, and all genetically modified cows were free of morphological abnormalities.
The production of more humanised, hypoallergenic milk is not a morally pressing/urgent issue to resolve within science, though since the study took all possible measures to minimise suffering in animal