Hands up if you're lactose intolerant. Quite a few of you, huh? Well, welcome to the wonderful world of science, where researchers have genetically engineered a cow, just for you.
A team from AgReasearch and the University of Waikato in New Zealand have genetically engineered a cow to create milk that's hypoallergenic and extra high in other proteins. The calf — called Daisy — produces milk with majorly depleted levels of the milk protein β-lactoglobulin (BLG), and increased levels of all casein milk proteins.
The researchers got to this point by first using mice designed to "mimic the mammary gland of a sheep" (no, I had no idea that was a thing either) and then created an RNA interference to block the production of the particular protein. The calf was then engineered to express the same two micro RNAs, and so produced milk without the allergen.
However, this is a long, long way from being the lactose-free cow's milk that I know some people are dying for. It's extremely expensive, hasn't been tested for human consumption, and as one doctor pointed out, it only stops one of the allergen proteins that people can react to — and actually boosts another. There's also the curious and unknown cause of the calf being born without a tail. Still, give it a decade or two, and allergy-free milk might yet make it to the refrigerator shelves of your local store.