People with milk allergies often turn to products like rice and soy milks. But now, in a twist, there is a new source of hypoallergenic milk in the offing: genetically-modified cows
. New Zealand scientists have produced a calf
that gives milk devoid of a protein, called beta-lactoglobulin (BLG), that causes an immune response in people with milk allergies. To get the milk this way, they had to engage in some fancy genetic footwork: They inserted a specially designed gene into cow embryos that prevented the production of BLG. When a gene is transcribed into a protein, a transcript called mRNA carries the relevant information from the cell's nucleus, where the gene is, to the protein-making machinery. The gene the researchers put into the cow embryos was specifically built to glom onto the mRNA for the beta-lactoglobulin protein, thus preventing it from reaching its destination, and preventing any beta-lactoglobulin from ...
