In a world’s first, researchers have genetically engineered a dairy cow to produce hypoallergenic milk that’s high in protein.
Some infants are allergic to a milk protein called beta-lactoglobulin (BLG), which is found in milk from cows but not from humans.
To help decrease BLG levels in milk, a team led by Goetz Laible from AgResearch in New Zealand first had to identify the protein’s genetic code.
They, using the code for BLG, they made a complimentary genetic structure that can shut down BLG production when injected into a cell. (The process of inhibiting the expression of certain genes is called RNA interference.)
They first tested the process in mice engineered to mimic the mammary gland of a sheep – resulting in a 96% reduction of BLG.
Then they transferred a treated nucleus into a cow egg cell, which was fertilized and implanted into a cow. From this, a healthy female calf was born (although without a tail, curiously).
When the researchers induced lactation in the calf, the milk produced contained high levels of protein and a dramatic reduction in BLG levels (compared with nonengineered calves).
The method might allow researchers to modify other properties of milk, such as levels of antibodies and hormones.
The work was published in the Proceedings of the National Academy of Sciences this week.
[Via New Scientist]
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