Milk allergy cured by a genetic switch

Posted by AFN Staff Writers on 4th October 2012

New Zealand’s AgResearch scientists have bred the first cow in the world to produce hypo-allergenic milk, by reducing the amount of milk whey protein, beta-lactoglobulin (BLG) which is known to cause allergies.

The process known as RNA interference, originally tested on mice, introduced two microRNAs (short ribonucleic acid molecules) to Daisy the cow to target the BLG protein. After hormonally inducing Daisy to lactate, scientists discovered that the cow had no detectable BLG protein.

It was also discovered that the cow had twice the amount of casein proteins that normally occur in cow’s milk, providing opportunities for calcium intake and cheese production.

The work by scientists at New Zealand’s AgResearch’s Ruakura campus has been published in the current edition of the prestigious American Science Journal Proceedings of the National Academy of Sciences (PNAS).

AgResearch Chief Executive, Dr Tom Richardson, said that the discovery was “incredibly significant in overcoming common milk allergies.”

“PNAS is one of the top journals in the world, and to be published in it reflects the world-leading quality of the science behind this discovery,” Mr Richardson said.

Reportedly, two in three infants suffer from an allergy to cow’s milk. The BLG protein is not found in human milk which can explain why many people suffer from the cow’s milk allergy.

The paper suggests that the process of using designer microRNAs to target other genes could provide an efficient tool to change additional livestock traits, for example to produce animals with enhanced disease resistance and/or improved lactation performance