Updated on 4 October 2012
Daisy was produced by scientists at AgResearch's Ruakura campus
Singapore: Scientists at AgResearch in Hamilton, New Zealand, have bred the first cow in the world to produce high protein milk that may be hypo-allergenic. The cow's milk can exclusively address allergies that are due to an immunogenic response against beta-lactoglobulin (BLG).
The work by the scientists at 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).
The AgResearch team, led by Dr Goetz Laible, wanted to discover if they could produce milk which contained less of a particular milk protein known to be allergenic."We were successful in greatly reducing the amount of BLG, a milk whey protein which is not in human breast milk and which can cause allergic reactions," said Dr Stefan Wagner, one of the lead authors of the paper. "Two to three percent of infants are allergic to cow's milk, and BLG allergies make up a large part of that percentage."
The news of the breakthrough comes even as dust over a controversial study on GM corn by a team of french scientists is yet to settle. The research published in the Journal of Food and Chemical Toxicology has faced much criticism from different quarters for being "politically motivated" and timed to coincide with the US presidential polls. The study claimed that dietary exposure to glyphosate and a Roundup Ready (RR) corn variety caused tumors, organ damage and premature death in lab rats. The mostly French research team was led by Gilles-Eric Séralini at the Université de Caen, France.
To come up with hypo-allergenic milk, the AgResearch scientists first tested the process in a mouse model engineered to produce the sheep form of BLG protein in mouse milk. Employing a technique called RNA interference, two microRNAs (short ribonucleic acid molecules) were then introduced into the mouse to knock-down the expression of the sheep BLG protein. This resulted in a 96 percent reduction in the sheep BLG protein in mouse milk.
They next produced Daisy, a female calf that was genetically engineered, to express the same two micro RNAs, this time to target the BLG protein that is also a normal constituent in cow's milk. They then hormonally induced Daisy to lactate. The resulting milk collected from Daisy had no detectable BLG protein and, unexpectedly, also had more than twice the level of the casein proteins that also normally occur in cow's milk.