WOULD you eat genetically modified cheese? That is the question food companies will be asking now that cows have been engineered to produce high-protein milk for cheese-making.
It is the first time that cows’ milk has been altered to produce food rather than pharmaceuticals. Dozens of extra copies of the genes for two milk proteins, beta and kappa-casein, were added to fetal cow cells, which were then cloned. Of 126 embryos implanted, 11 calves survived till weaning. The milk of nine of them contains twice as much kappa-casein as usual and up to a fifth more beta-casein (Nature Biotechnology DOI:10.1038/nbt783).…
